Expert witness Professor Luke Bisby testifies about ACM panel rivet fixing experiments, the flawed transposition of National to European fire classifications, and the inadequacy of desktop assessments for building regulations compliance.
00:00:27 good morning everyone welcome to today's hearing uh today we're going to continue hearing evidence from Professor Luke Bisby so I'd ask uh Professor Luke Professor Bisby to come back in
00:00:47 [Music]
00:00:52 please good morning Professor Bisby good morning U ready to carry on with your evidence I I am thank you thank you very much indeed yes Mr thank you Mr chair good morning to you good morning members of the panel Professor Bisby good
00:01:03 of the panel Professor Bisby good morning to you good morning now we had arrived I think at the point of examining the harmonization uh of uh standards when we broke on Monday evening what I'd like to do before we go back to that question
00:01:15 do before we go back to that question please uh is to examine something that you said on Monday uh which involves us looking back into work package two and exploring that in a little bit more detail if I may sure so that's what we're going to do can we please have the
00:01:27 we're going to do can we please have the work package to report up on the screen lb y WP 270 is [Music]
00:01:42 1 that's the first page of it can we go in it please to page
00:01:47 75 now this is your table five which is a summary table showing a range of parameters of interest from all experiments these are discussed in more detail in the following sections and
00:01:58 detail in the following sections and then you set out the 37 experiments that you conducted M uh by row number 1 to 37 uh with the number of the experiment number listed uh and then organized by
00:02:10 number listed uh and then organized by group P PF MW HS and NC MH and what that stands for essentially uh and then foil fac yes no ACM fixing case Figure 8
00:02:24 fac yes no ACM fixing case Figure 8 we're going to come back to that in a moment uh and then Peak hrr heat release rate
00:02:30 rate uh measured in kilowatts time to Peak hrr in seconds critical time in seconds uh Mass loss in percentage terms uh uh insulation Mass loss in percentage terms
00:02:42 insulation Mass loss in percentage terms and then total heat released in mega so that's how the table works am I right about that yep yes now then if if uh you go please to the bottom of page 74 the previous page paragraph 439 you say this
00:02:56 previous page paragraph 439 you say this under the heading 7.2 summary results table five presents present summary outcomes for each of the individual experiments included within this report the initial 15 experiments that we performed have not been presented in
00:03:07 performed have not been presented in this report because they these were used to develop the experimental geometry and and procedures employed for the remainder of the experiments as well as to refine the choices of instrumentation types and locations
00:03:18 types and locations MH so is it correct that um when you um arrived at your conclusions you took into account all of the outcomes presented in table five that's correct
00:03:30 five that's correct yes now let's go to table five again please next page page 75 column six uh which is the ACM fixing case that I directed you to earlier uh and in that
00:03:41 directed you to earlier uh and in that as you can see we are directed to figure eight figure eight is on page 47 if we can please go to
00:03:49 that now page 47 Figure 8 is entitled at the foot of the page schematics showing rooting patterns or routing patterns and fixing locations on the inside face of
00:04:00 fixing locations on the inside face of the ACM rain screen sections I.E the ACM face exposed within the cavity for a edge routed B Edge and ins inside face routed and C and D Edge routed and face
00:04:13 routed and C and D Edge routed and face riveted cases all dimensions in millimeters not to scale you see that yes now is it correct that fixing case b on the top right hand corner of the page
00:04:26 on the top right hand corner of the page Incorporated a number of routing lines correct and you you can see those can't we in the top right hand corner blue panel with the with the lines across it yeah that's right in addition to the edge routing uh there was a line or a
00:04:39 edge routing uh there was a line or a series of lines routed across the face yes and that that exists in all of them I think doesn't it in all of the fixing case b cases yes yeah yes uh and in in all cases there is a vertical routing
00:04:51 all cases there is a vertical routing line correct down the sides down the sides now um if we go down to page 48 and look at T
00:05:02 three uh this is entitled overview of work package two experiments presented here in and parameters varied amongst them uh and then you can see the first is celotex cavity
00:05:14 is celotex cavity insulation uh and there are um some 12 I think experiments Row 1 to 12 is it right that those experiments used all
00:05:25 right that those experiments used all four types of fixing case a to d with RS 5080 as the insulation material yes let me just I'm just
00:05:36 material yes let me just I'm just looking at the ACM fixing case column yes
00:05:39 yes yes uh and yeah indeed and of those two only two uh were done without a foil facer namely rows three and four where there's an N that's right
00:05:52 there's an N that's right right um why was that why was what was the reason for using the four different types of fixing case in experiment incorporating only um the RS
00:06:03 incorporating only um the RS 5080 rather than any other type of insulation uh I mean just to keep the number of experiments down to a reasonable level you know we we could have there are so many factors that we
00:06:14 have there are so many factors that we are looking at in this experimental program that to do every combination with every other combination would have meant hundreds of experiments and you know you have to keep in mind performing
00:06:25 know you have to keep in mind performing a single one of these experiments takes about a half a day uh a half a day of about well a minimum of three and up to five or six people's time uh so it's not
00:06:36 five or six people's time uh so it's not an insignificant expense in time or money to be doing this work and we wanted to uh try to get a sense of the parameters of Interest without uh well without wasting resource to be honest
00:06:48 without wasting resource to be honest right did you form a view about the impact of that uh approach taking into account proportionality of resource and time uh on the outcome of your
00:07:00 time uh on the outcome of your work yes as we went through I mean obviously when you're looking at the effects of any parameter uh if you're a good experimentalist you're asking yourself
00:07:11 experimentalist you're asking yourself whether you are capturing the possible influences of other parameters to the extent that you can do that within your program so yes of course we were doing that and of the 12 um experiments that we can see using
00:07:22 12 um experiments that we can see using celotex RS 508 um only two had a foil faer sorry 10 had a foil faer only two had no foil faer why only two without foil facer uh
00:07:35 faer why only two without foil facer uh again just to keep the number of experiments at a reasonable level we could have done I suppose we could have done more uh without a foil facer um but the the fixing case series if you like
00:07:49 the the fixing case series if you like uh the the if if you were to set out to only understand the influence of the fixing case whether it's Edge routed
00:08:00 fixing case whether it's Edge routed face routed or Edge routed and riveted with the two riveting configurations that we used um you wouldn't necessarily want to vary another parameter that's just going to muddy the Waters of
00:08:11 just going to muddy the Waters of understanding how the fixing case influences the outcome so so what we did was we stuck with the one insulation case I mean you could equally ask why didn't we try it with mineral wool why didn't we try it with phenolic foam why
00:08:23 didn't we try it with phenolic foam why didn't we try it with no caety why didn't we try it with the water cooled uh opposing face and the answer is because we're trying to understand the influence of ACM uh routing and fixing case um and
00:08:36 ACM uh routing and fixing case um and what we were looking for was differences in behavior that would help us to understand how the product's behavior is going to change under that one set of conditions and I I I really feel like
00:08:49 conditions and I I I really feel like the differences that we observed between the performance of the systems
00:08:53 systems um uh did answer that question did help us to answer the question and and you know the question we trying to answer with those experiments was what impact does routing and uh riveting have on the
00:09:06 does routing and uh riveting have on the performance and and what are the physical mechanisms by which those influences would manifest in the outcomes and I think we did that if you look uh at all the other celotex well
00:09:17 look uh at all the other celotex well the other celotex tests lines 13 to 17 uh and on down the table kingsb K15 mineral wool heat sink and no cavity
00:09:28 mineral wool heat sink and no cavity they are all a that's right is there a scientific reason why you didn't or didn't need to go on to test uh those either with or without a foil facer
00:09:40 either with or without a foil facer under any other ACM fixing
00:09:45 case I mean is there a scientific reason uh I mean in so far as we felt that with the uh insulation the opposing face condition that we had used which was the
00:09:56 condition that we had used which was the celotex insulation the 5080 with the foil that we had sufficiently understood the influence of of the routing and fixing condition so there you know I
00:10:08 fixing condition so there you know I don't I don't think for an instant that that the conclusions that I've drawn about the way the fixing condition influences the outcome would change at all if I were to use some other
00:10:19 all if I were to use some other insulating case I suspect if I I suspect that if we had performed those experiments uh with without foil with the celotex with without foil for the kingspan product product or indeed with
00:10:30 kingspan product product or indeed with without foil for the mineral wool um that the influence of fixing case that we would observe would be the same I I don't think we'd see any difference I mean if the inquiry the chairman uh
00:10:43 mean if the inquiry the chairman uh wants to insist that we do those experiments we can do those experiments I'm not sure my colleagues will be very happy about that um but uh but we could certainly try no but really what I'm after is whether you can can in your opinion could tell us that it would be
00:10:55 opinion could tell us that it would be scientifically unnecessary I believe it's scientifically unnecessary yes now um do we go back to page 75 please table five
00:11:08 again page
00:11:11 75 table five thank you yes uh this is the summary table um is it right that the results for fixings a b and d were similar uh or comp from a b and d
00:11:27 similar uh or comp from a b and d d uh in Broad terms in that all three of those cases uh just thinking back to the diagrams all three of those cases resulted in in escalation the full
00:11:39 resulted in in escalation the full involvement of the ACM yes in so far as that's the case they were similar yes yeah is is it also the case that the results of your testing showed that the results for experiments using fixing Case C were better than all the other
00:11:51 Case C were better than all the other cases sa for heat sync and no cavity uh that's correct yes yes and it looking at the results for for C in
00:12:04 looking at the results for for C in table five that's row 9 and 11 um did the ACM sustain flame uh the ACM did yeah there was melting and dripping of polythylene INF
00:12:15 melting and dripping of polythylene INF flaming even with fixing Case C that's correct right and was there migration of the polyethylene yes but was it limited in any way it less so than in the other cases yes can you quantify that um
00:12:30 cases yes can you quantify that um by looking at the masses lost from the ACM I'm sure we could from memory I can't but I'm sure we have the data whether those data are in the report I can't remember actually is it the case
00:12:42 can't remember actually is it the case that could you say that the migration of the polyethylene was more limited uh what I from memory what I would say is that the migration of the polyethylene whilst the line burner was
00:12:54 polyethylene whilst the line burner was in place so in the initial four minutes of heating was broadly similar uh but that beyond that point uh once the line burner was removed there was
00:13:05 the line burner was removed there was less migration of the polythylene uh from the ACM yes uh and did the insulated
00:13:12 insulated cavity accumulate heat or did it not uh depends what you mean by accumulate um I mean yes there I mean there's a fire there's a fire in the
00:13:24 there's a fire there's a fire in the cavity so the cavity is going to get hot yes yes
00:13:30 now let's um uh go please to page 79 paragraph
00:13:39 449 you say there uh the following initial C this is 448 I should say the following initial comments can however be made on the basis of the data presented in table
00:13:51 basis of the data presented in table five and in figure 30 to figure 34 and then 449 says not all experiments progress Beyond critical time and grew to achieve full involvement of the ACM
00:14:02 to achieve full involvement of the ACM for example experiments with no cavity with a heat SN cavity and those in which the ACM was riveted at its base fixing Case C in figure8 did not progress to full involvement of the ACM in these
00:14:14 full involvement of the ACM in these cases the peak hrr insulation Mass loss and total heat released were as should be expected expected much less than in all other cases where full involvement of the ACM
00:14:26 of the ACM occurred now that's what you say there and let's go in addition please to page 111 figure
00:14:37 58 uh and that's uh entitled Mass loss of ACM measured during Baseline experiments on cladding Arrangements using celotex RS 508 for ACM fixing
00:14:48 using celotex RS 508 for ACM fixing conditions A B C or D and then you you identify the experiments and in particular 36/40 which I think was uh was fixing C
00:14:59 36/40 which I think was uh was fixing C wasn't it I'll have to take your word for it but if that's what the table says then and just looking at the table above it there's a key and fixing condition C is a long Dash followed by a DOT correct
00:15:13 is a long Dash followed by a DOT correct uh and you can see is this right you can see that the uh the graph the chart shows that instead of is this right instead of dropping away
00:15:24 away uh it it it it shallows out and moves across so those are those two lines are two experiments um so that the experiments were run yeah twice in in
00:15:35 experiments were run yeah twice in in indeed and are those that run across at around about Ju Just Over minus 200 Mass loss in grams those done under fixing
00:15:46 loss in grams those done under fixing condition C that's right right yeah so I mean so this answers the question you asked me before yes yes so thank you then then let's go to page 112 paragraph 583
00:16:01 where you say um the change from fixing condition a to fixing condition C which essentially entails installing nine aluminium rivets through both faces of the ACM panel over its lower third
00:16:12 the ACM panel over its lower third results in the cladding Arrangements tested never in italics never growing to full involvement of the ACM this can be attributed to the fact that the rivets mechanically hold the aluminium skins together provided that the rivets remain
00:16:24 together provided that the rivets remain in place and prevent opening up of the acm's aluminium skins this reduces the exposed surface of the area of PE that can burn and also discourages mobilization of molten PE into the drip
00:16:36 mobilization of molten PE into the drip tray this reduces stroke slows the supply of fuel to the pool fire burning at the base of the ACM and prevents escalation in our cladding system configuration and for our ignition
00:16:48 configuration and for our ignition Source um now the first is has is that evidence in that paragraph still your evidence Professor yes yes let's then go to the transcript please for Monday this
00:17:00 to the transcript please for Monday this week um day 290 and let's go within that to page
00:17:12 34 and at line six you say this but if one manages by any mechanism in one's installation of acmpe panels to prevent the aluminium skins from opening up
00:17:23 the aluminium skins from opening up either with rivets or with framing or bracketing or you know I'm aware that over the years in standardized testing of ACM products sometimes little U sections of metal would put around the edge of panels to try to keep the faces
00:17:34 edge of panels to try to keep the faces together that would improve performance now in our experiments what that tended to do was to make it take longer for escalation to full involvement of the ACM to occur but you still do get
00:17:45 ACM to occur but you still do get eventually full involvement of the ACM and you still do get approximately the same total amount of energy release so the presence of rivets or the presence of any mechanism that holds the
00:17:56 presence of any mechanism that holds the aluminium skins together what it does is it prolongs the time until things go really bad until you get a lot of burning and you get this rapid escalation that's right now are you able
00:18:09 escalation that's right now are you able to uh reconcile what you said in the transcript there with what I just shown you from your report in relation to appendix
00:18:20 C uh I'm not I'm not sure I understand the question uh well when you gave the answer that I'm showing you on the screen did you intend to include fixing Case
00:18:31 Case C yes uh so are you are you saying that even with if with fixing Case C your your experiments tend to show that it
00:18:42 your experiments tend to show that it would take longer for escalation to full involvement but you still do get eventually full involvement of the ACM yeah absolutely absolutely yes what is it about your experiment that show
00:18:53 is it about your experiment that show that very important Point very important Point uh our exper so we left so we left our line burner in as you recall from last week I I I I I intended and
00:19:04 last week I I I I I intended and hopefully I did labor the point that we left the line burner in for 4 minutes so you take the line burner in you leave the line burner in for 4 minutes why four minutes is an interesting question why not 3 minutes why not 10 uh and the
00:19:18 why not 3 minutes why not 10 uh and the answer is because after 4 minutes we observed uh in those initial experiments uh that I that I've mentioned when we were trying to to to figure out what our
00:19:30 were trying to to to figure out what our Baseline experimental scenario ought to be um 4 minutes was the amount of time that the line burner was left in where we we mobilized sufficient PE that we
00:19:41 we we mobilized sufficient PE that we got uh a a pool of polyethylene burning in the drip tray uh and that when that line burner was removed we were if you like on the
00:19:52 like on the edge of
00:19:55 edge of escalation uh if we had taken the line burner out after 3 minutes maybe there wouldn't have been sufficient polyethylene to then heat the system above if we left it in for s or 8
00:20:06 above if we left it in for s or 8 minutes maybe um we would have uh have such a large pool fire that no matter what we did they would escalate so what we were trying to understand was uh the
00:20:17 we were trying to understand was uh the extent to which uh changes in various parameters would either increase or decrease the prognosis for that fire going to full involvement of the ACM um
00:20:28 going to full involvement of the ACM um now again one could say okay well let's repeat the the entire experimental program but instead of leaving the line burner in for four minutes let's leave it in for 6 minutes or 2 minutes and
00:20:39 it in for 6 minutes or 2 minutes and what changes do we observe um but again you end up in the situation where your questions become sort of how long is a piece of string questions we could test
00:20:50 piece of string questions we could test everything um and you know the the the the point uh the point really of the the fixing case C outcome in my mind is the
00:21:03 fixing case C outcome in my mind is the point that I made uh I think on Monday uh of this week which is that when when when we perform experiments when we perform standardized
00:21:15 experiments when we perform standardized compliance tests uh on these products like the bs476 part 6 and 7 tests like the uh SBI test
00:21:28 everybody knows how an S SBI test is performed because it says in the SBI test standard this is how you perform the
00:21:36 the test if you are a manufacturer um you you could and I suspect you would uh think quite hard about how your
00:21:47 would uh think quite hard about how your product is going to perform in that very specific standardized test scenario because what you need in order to access the market is your your B Class or whatever it is
00:21:59 is your your B Class or whatever it is that you need think about the Euro class probably if you're manufacturing ACM what you want is a Class B for your product um and and you know the time duration of an SBI test
00:22:12 know the time duration of an SBI test you know the heat output of the burner and you
00:22:17 and you know maybe uh what your product is going to do under those scenarios and and maybe you increase the aluminium skins a little bit to give them a little bit more thermal Mass Maybe maybe you fold
00:22:29 more thermal Mass Maybe maybe you fold the edges of your aluminium around to give you a little bit more time maybe you add one or two more rivets in your experiment because you know that the rivets are going to help you to get just
00:22:40 rivets are going to help you to get just past the 5 minutes or the 10 minutes or the 20 minutes that you want and so what fixing Case C shows us is that for a system that would otherwise fall foul of
00:22:51 system that would otherwise fall foul of my very specific experimental scenario I can't engineer it to get through that scenario if I know what's going on and so when you run an SBI test on an acmp
00:23:04 so when you run an SBI test on an acmp product and you run it with a rivited system and you get a class B and you run it with a c with a cassette system and you get a Class D or E you know why that happens I think uh
00:23:20 E you know why that happens I think uh and that's why you run the riveted case uh and then you claim that your product has achieved Class B because that's the result you want you don't claim that your product has achieved the class E uh
00:23:31 your product has achieved the class E uh and I and that that that me that method that is used I suspect quite widely across this
00:23:42 used I suspect quite widely across this industry
00:23:44 industry uh is is very dangerous it's very dangerous uh and and it's a problem professor in in the light of the
00:23:55 problem professor in in the light of the question that Mr milet asked you couple of moments ago you still have on the screen I think the transcript of day 290 is that right yes in which you said in
00:24:07 is that right yes in which you said in lines 14 to 19 it took longer for escalation to full involvement with the riveted system is that
00:24:16 that right that's right but eventually you still get approximately you still get full involvement of the ACM and you still get approximately the same total energy released ah now that's an interesting point so in in in the case
00:24:28 interesting point so in in in the case of fixing Case C no maybe that's why this has come up yes no you're absolutely right to pick up on that that is not true that statement is not true in the case of fixing Case C in our experiment that's what I wanted to check because I was looking back at paragraph
00:24:40 because I was looking back at paragraph 583 of your report in which you say that the cladding Arrangements never grow to full involvement and I think that was thank you point Thank you for
00:24:51 thank you point Thank you for highlighting that and know you're absolutely that is absolutely right what I would say is however uh if we had if we left the line burner in for few more minutes it it would have in my view yeah
00:25:02 minutes it it would have in my view yeah all right thank thank you but we didn't didn't and you're absolutely right to to pick me up on that you're absolutely right yes yes that that was that that's that's the point but your your um additional evidence is of course
00:25:16 additional evidence is of course um useful um but leads to another question I think which is whether the fire that you used in the burner um bore any resemblance to
00:25:28 burner um bore any resemblance to um your average external fire on an ACM cladding
00:25:34 cladding system what's an average fire on an acmn system no it didn't probably in what way not uh any number of any number of fires in an external clading system is
00:25:46 in an external clading system is possible you know um do you have uh do you have a a kitchen fire because a fridge has ignited in a kitchen and you have fire venting out the window uh do
00:25:57 have fire venting out the window uh do you have a fire because the fire has not vented out the window it's vented out the side of the window uh do do you do you have um some children playing with matches do you have a a some rubbish
00:26:09 matches do you have a a some rubbish that's been set on fire as occurred at NOS Ley uh do you have some other do you have an electrical fault in a lighting system that causes a lighting fixture to night and I mean again how long is a
00:26:21 night and I mean again how long is a piece of string the the the the the point of our experiment as I as I I know I labored the point uh um last week is is these are not reconstructions we are
00:26:32 is these are not reconstructions we are not attempting to simulate any particular scenario we're attempting to understand what happens under a scenario that we have chosen semi- arbitrarily and yeah I mean I think that's a really
00:26:43 and yeah I mean I think that's a really important Point um you say semi arbitrarily uh you got a line burner in there for 4 minutes does that represent any kind of uh any kind of minimum or
00:26:54 any kind of uh any kind of minimum or positioning in relation to the kinds of heat that you would need uh to generate the fuz that you get in your
00:27:04 experiments it represents what I would consider to be a a very small uh thermal insult if you like ignition Source uh that is that line
00:27:16 ignition Source uh that is that line burner is not a big fire that line burner is a very small fire and one of the reasons we chose a very small fire um is because once you have a once you
00:27:27 um is because once you have a once you have a big fire the uh the acmp in particular uh is away once you have a big far yes now do you consider that that it is the case that
00:27:39 consider that that it is the case that you can conclude from your experiments that the better performance of the ACM under fixing Case C is attributable to the rivet fixings precluding or inhibiting the delamination of the
00:27:50 inhibiting the delamination of the aluminium faces of the panels uh yes I think it's a combination of two things I think it's I think it's it's that the um as we saw when we looked at the video of
00:28:02 as we saw when we looked at the video of uh in work package one of the acmp with the rear uh face held uh I don't if you can remember back but hopefully you can but what we observed in that experiment
00:28:13 but what we observed in that experiment was that the polyethylene you know when I talk about melting and dripping and flowing of the polyethylene I think people have this idea that I'm talking about water uh melting dripping and flowing and if you had water between
00:28:25 flowing and if you had water between those two skins it would just flow out and flow all over the place uh the polyethylene uh is not um does not flow like water it it it oozes uh and and
00:28:36 like water it it it oozes uh and and drips and we saw that in those experiments so so the the the factors that are relevant one having the rivets hold those two aluminium skins together makes it harder for the polyethylene to
00:28:47 makes it harder for the polyethylene to mobilize and flow out from between the two aluminium skins um you know if you take two sheets of glass um uh and you put water between them and you stick them together they will stick together
00:28:59 them together they will stick together just with water there right and so and that's because of the surface tension and what's going on so so there's that factor and there's also that if you rivet the aluminium skins together then as the aluminium uh plates heat up
00:29:13 as the aluminium uh plates heat up experience thermal gradients they want to to warp and deform as they warp and deform we observed in our experiments and I think you have to expect it uh once the polyethylene can no longer uh
00:29:25 once the polyethylene can no longer uh maintain adhesion you get them kind of opening up against each other and you get large gaps form and if you get a large gap form and you get air in between the Gap then now your polyethylene doesn't need to mobilize to burn it can burn in the Gap um so
00:29:38 burn it can burn in the Gap um so there's those two factors it's the it's the mobilization and the opening up right that causes the fire to escalate Professor can I just sorry to interrupt again can I just ask you this looking at
00:29:49 again can I just ask you this looking at the um figure eight which is the schematics of your testing regimes um I note that the in the case of both fixing Case C and fixing case
00:30:03 of both fixing Case C and fixing case D there were uh a number of rivets I think the most interesting one probably for this purpose is fixing Case C where you had nine rivets all at the base of
00:30:14 you had nine rivets all at the base of the
00:30:15 the plate um Mr chairman can we just have that up on the screen you may have it but it's 848 I don't think it's generally available page 48 is
00:30:28 47 47 I apologize 47 figure
00:30:35 eight we got that up yet back of page 48 47
00:30:47 yes 47
00:31:06 Mr chair I'm sorry about that don't I've interrupted you well we've got it now we've now got it um we can see that in fixing Case C you've got nine rivets at the bottom of the plate and in fixing
00:31:17 the bottom of the plate and in fixing case D I think you have nine rivets in the middle of the plate is that right that's right now um if you were fixing these plates to a building on the riveting system and not sure quite how
00:31:28 riveting system and not sure quite how many rivets you would put in but let's assume for the present purposes that you have one at Each corner because you're not the purpose is not to hold the plates together the purpose is simply to
00:31:39 plates together the purpose is simply to attach the plates to the building on a real building yes yes do your experiments and these configurations enable you to express any opinion about
00:31:50 enable you to express any opinion about the way in which a plate fixed with four rivets one at Each corner would perform uh no in uh you know in in specific terms
00:32:04 no in uh you know in in specific terms no um but of course I think it's quite unlikely that on a real building you would have a panel that's a half a meter by a meter anyway you probably have much larger panels on an actual building uh
00:32:17 larger panels on an actual building uh and then you know with scale potentially changes everything it what's interesting about I mean you've picked up on a very important Point Mr chairman which is um the difference between fixing case C and
00:32:29 the difference between fixing case C and fixing case D both with nine rivets but the rivets in different locations and an obvious question which I didn't cover in my presentation last Friday is why did we why did we do that um and the answer
00:32:40 we why did we do that um and the answer was linked to the question I was asked a few minutes ago about the mechanisms by which um the rivets are assisting if you like um these panels to perform better in a fire um and and the rivets in
00:32:52 in a fire um and and the rivets in fixing case D were moved up because we were interested in um seeing uh we were interested in seeing the extent to which the ACM panel would open
00:33:03 extent to which the ACM panel would open up at its base as a consequence of there not being rivets and therefore open up allow burning mobilize PE now to do that properly as a controlled study you'd want to do a lot more different
00:33:14 want to do a lot more different configurations of rivets but again with limited time and resource we felt that that that that and I think for fixing case D we only ran a single a single experiment as opposed to the duplicate
00:33:25 experiment as opposed to the duplicate that we were doing CU it was really I remember the conversations it was really when we did fixing Case C we thought oh that's interesting let's just do one more thing just to satisfy ourselves
00:33:36 more thing just to satisfy ourselves that we that we know what's happening here and after we did it we were satisfied that we did understand what was happening yes I mean the impression one gets is that fixing Case C demonstrates that uh any mechanism which
00:33:49 demonstrates that uh any mechanism which holds the two skin aluminium skins together is effective in reducing the amount of uh combustion yes of the PE um but of course the
00:34:03 yes of the PE um but of course the configuration of the rivets in fixing Case C involves um quite quite good fixing of the of the bottom of the panel quite closely spaced rivets yes quite closely spaced rivets exactly whereas if
00:34:14 closely spaced rivets exactly whereas if you had much the rivets placed much further apart inde you might find that it wasn't as effective yeah I mean one one way that that could have been done and again I hesitate um to suggest we
00:34:25 and again I hesitate um to suggest we should perform more experiments because I do think we understand everything that we need to understand uh would would have been to do if you like fixing case a without Edge routing the
00:34:37 fixing case a without Edge routing the panel and just have because the the white dots you can see on these diagrams are the uh through bolts that attach the ACM to the aluminium frames MH uh and if
00:34:48 ACM to the aluminium frames MH uh and if we had done uh simply that case then we would have seen what is probably a more realistic uh situation to What would on a building but again with the panel size
00:35:00 a building but again with the panel size and uh you know there's all sorts of of subsequent questions so the the aluminium frame to which the ACM plate is fixed is going to provide some rigidity and prevent deoration and so
00:35:11 rigidity and prevent deoration and so that you know it's it's much too complicated to try to say this is representative of a building um it's it's not representative of a building it's interrogating mechanisms in physics
00:35:22 it's interrogating mechanisms in physics that's the point of it all right thank you very much yes and and does that tell us that then May well be some riveting configurations such as fixing Case C uh which uh will uh
00:35:38 fixing Case C uh which uh will uh perform much better uh yes and some that will perform much worse yes now I mean the I think it's an important point
00:35:49 it's an important point the I'm not suggesting for an instant that people should be encouraged to use ACM MP but just rivet it uh I'm I'm
00:36:02 ACM MP but just rivet it uh I'm I'm saying exactly the opposite of that I'm saying you know this this is not a product that should be used ever because of the way once it goes It goes um and
00:36:13 of the way once it goes It goes um and whether you rivet it or you or you route it or you fold it or you twist it or you bend it I don't I don't mind it has a core of polyethylene of
00:36:24 mind it has a core of polyethylene of unmodified polyethylene that will burn a lot
00:36:28 lot uh and uh and whether or not it burns a lot in a standard testing scenario where the specific configuration used has been
00:36:39 the specific configuration used has been engineered or gamed if you like in order to get through the test is not the right question you know the right question is uh under the full range of fire scenarios that I might get in my
00:36:51 scenarios that I might get in my building with this product applied in the way that it's applied on my building does it have the potential to cause a very big fire and the answer is going going to be unless it's used in in
00:37:03 going to be unless it's used in in substantial quantities yes it does have that potential and therefore given that there are other Alternatives that are only incrementally more expensive don't use
00:37:11 use it well now you saying that last answer um
00:37:18 um that whether you rivet it or route it or fold it or twist it or bend it
00:37:25 it uh uh it it it it will go eventually um and I I've perhaps misp paraphrased what you've told us but how does
00:37:34 does that reconciled with what you said paragraph
00:37:38 paragraph 583 and the answer you gave the chairman about what you said in the transcript yesterday on
00:37:46 Monday uh okay maybe I'm being maybe I'm being slightly too definitive it will go if you don't have a fire that is sufficient to make it go then maybe it won't go
00:37:59 to make it go then maybe it won't go sure but the kinds of fires that we imagine when we think about external fire spread on buildings uh the kinds of fires that Professor Terrero has expressed
00:38:12 Professor Terrero has expressed previously uh we need to assume that there's a probability of one that that we will get this fire uh as a designer you know we're required to assume that that we that we will get a fire that's
00:38:24 that we that we will get a fire that's why we're designing the building to resist fire if we could assume that there isn't going to be a fire then I mean all of this is a bit moot um but given that we have to assume as designers that there is going to be a fire the fire that we are going to get
00:38:35 fire the fire that we are going to get is going to be a more onerous fire than our little line burner that we've used in our
00:38:41 in our experiments Mr M I'm sorry to interrupt you yet again but I think it's quite important that we get the transcript right on page 27 line 8 um Professor Bisby is recorded as
00:38:54 8 um Professor Bisby is recorded as having said the answer is going to be unless unless it's used in substantial quantities and I'm pretty sure he said or meant insubstantial unless it is used in insubstantial quti that is an
00:39:07 in insubstantial quti that is an important
00:39:08 important distinction so we can get that corrected I think it could be corrected right now I think in the
00:39:17 transcript and obviously the word insubstantial is
00:39:23 subjective yes now can I take you back to page 75 five then please same
00:39:34 report Table five uh and you can see fixing class or fixing Case C rows 9 and 11 that's experiments 36 and
00:39:46 experiments 36 and 40 uh and um if you go to page 77 please you can see figure 31 there uh which is the peak heat release
00:39:57 there uh which is the peak heat release rate
00:39:59 rate and at page 111 just have that in front of you first of all before I come to the question uh you see at figure 58 on page 111 the mass loss of
00:40:10 111 the mass loss of ACM uh measured during the Baseline experiments and we and we looked at that before going back if we can then having shown you that to page 75 and table five
00:40:21 shown you that to page 75 and table five on that
00:40:22 on that page you can see the heading for Peak hrr
00:40:27 hrr um what what does that tell us what does that statistic tell us so far as um the fixing Case C is concerned uh Peak heat release rate in
00:40:40 concerned uh Peak heat release rate in the context of these experiments is actually not that useful a metric uh it should be said uh We've included it because Peak heat release rate is a is a value that is typically given when people run um fire tests and fire
00:40:53 people run um fire tests and fire experiments uh what's interesting if if we can go if you go back to the figure that we showed a minute ago I can't remember what number it was it was the figure that gave the P release rates for the different experiments uh figure uh
00:41:06 the different experiments uh figure uh 58 I think on page 111 uh no no sorry 31 page
00:41:16 77 yeah so you can see you know there's a huge variance in the uh py release rates that are given in this uh in this yes figure fixing cases a b and
00:41:31 yes figure fixing cases a b and d uh all if we were to go back and look at the table they all escalated the full involvement of the ACM and yet they have very different Peak heat release rates if we were to do a comparison of total
00:41:43 if we were to do a comparison of total heat released from start to finish of the experiment we would see them agree much more closely with one another so the peak heat release rate is giving you a snapshot of one instant in time but it's not telling you really anything
00:41:55 it's not telling you really anything about how you get to that point in time or what then happens after that time and how much energy is released in total um what's interesting about figure 31 is the fixing uh condition D case uh
00:42:10 the fixing uh condition D case uh because in fixing condition D which is the case where you have nine rivets sort of halfway up uh or two3 one third of the way up the the panel um uh it
00:42:22 the way up the the panel um uh it progressed much more much more slowly um so it took longer to escalate the full involvement of the ACM if I remember correctly but when it went it
00:42:33 remember correctly but when it went it went very suddenly and very violently and and we we we believe I believe that that's because because it took so long to get there that a lot of preheating of
00:42:44 to get there that a lot of preheating of the polyethylene in the sample had occurred over that long period And so when the rivets eventually let go and the aluminium skin skin uh is is removed um it really takes off very
00:42:56 removed um it really takes off very quickly
00:42:57 quickly and so the time scales over which you have like you have a preheating of the ACM panel um the the manner in which the inside aluminium skin drops off does it
00:43:08 inside aluminium skin drops off does it does it gradually get eaten away as was the case where we have the lines routed across it and the plates fall off sequentially or does it all drop off in one go and you've just got a big surface of polyethylene um is what influences
00:43:20 of polyethylene um is what influences this peak heat release rate um but so this the peak heat release rate is telling us more if you like more about the mechanism by which the polyethylene is becoming exposed than it is about
00:43:31 is becoming exposed than it is about sort of the the consequence if you like of that I don't I don't know if that's a perhaps not a very clear answer but the short answer is Peak heat release Peak heat release rate for these experiments
00:43:42 heat release rate for these experiments is not a very useful metric in comparative terms unless you think quite hard about what you have observed from a mechanics perspective right yes now um let me revisit one or
00:43:54 right yes now um let me revisit one or two things we've covered already this morning just by reference to transcript again uh from day 290 if we can get back to that please and go to page
00:44:08 35 and this covers ground I'm afraid we covered this morning but just to just to complete the the picture on it you set line one there you know the fact that riveted systems are apparently able to
00:44:20 riveted systems are apparently able to achieve a Class B result in the Euro classification system when tested in an SBI but a cassette system does much work what's interesting about that is that if you let an SBI test run with a riveted
00:44:32 you let an SBI test run with a riveted system my expectation is that eventually you would see the same result it's just that because of the time scales that are involved you don't necessarily push the panels to that point now given your
00:44:43 panels to that point now given your results and your conclusions from your experiments with fixing Case C as we've now seen why would your expectation be that you would see the same
00:44:52 result um if you let an SBI test run for long enough eventually it's going to get to that polyethylene core and that polyethylene core is going to burn it's going to release all its energy and the
00:45:03 going to release all its energy and the fire is going to to escalate going to get big I mean thinking about fixing Case C is it isn't it the case that it doesn't necessarily follow that an SBI test on a panel in a riveted system
00:45:14 test on a panel in a riveted system would lead to full
00:45:17 combustion I mean nothing is certain in life uh but I think it's probable I mean the the uh the line burner that we used uh I think is is 30 or 40 kilow in an
00:45:31 uh I think is is 30 or 40 kilow in an SBI I think you've got was 100 300 kilowatts you got bigger Source um bigger Source left for longer I think it would I think it would
00:45:42 longer I think it would I think it would go uh I mean and I I believe there's some evidence that later attempts to achieve a b result even with a riveted system were unsuccessful um I can't remember where that evidence
00:45:55 is and then if we go back to your report please at page
00:46:07 112 uh you say there at paragraph
00:46:15 585 that's not I think the right report sorry it's the wrong
00:46:22 report can we go back to the report we were on please uh which is at lb WP 2701 page
00:46:40 112 thank you uh page 58 page 112 paragraph
00:46:46 paragraph 585 uh and you say uh in the last sentence thus the potential benefits of riveting are not always realized and indeed under some circumstances riveting may actually result in more
00:46:57 may actually result in more severe burning eventually do you consider that the results for fixings A and B were broadly similar uh in so far as the total amount
00:47:08 similar uh in so far as the total amount of energy released when the system escalated to full involvement yes yes uh although the I mean from the plot we just looked at the uh Peak release rates were less I'd have to look at the data
00:47:20 were less I'd have to look at the data to look at the time to escalation to know how that varied uh right let's go back to page 48 and table three on that page just to make that
00:47:30 clear there it is um does this show that the differing extent of the routing doesn't affect the results
00:47:39 results uh this table doesn't have the results in it I think it's the next or a different table that we need uh let's go to page 111 yeah this table just shows
00:47:50 to page 111 yeah this table just shows what we did yes but it has the that's true uh let's go to page 11 one
00:47:59 um maybe it's 75 apologies paragraph page
00:48:04 75 table eight table five looking at that does that tell us that the differing extent of the routing um allocated by case
00:48:16 routing um allocated by case fixing
00:48:19 fixing uh I'm just having to go through it now quite carefully yes uh so d
00:48:27 uh so d uh takes longer C you've got 232
00:48:34 232 B
00:48:36 B 500ish okay so the A and B cases look broadly similar in terms of their time to
00:48:41 to escalation uh C
00:48:55 uh see is pretty
00:49:01 variable D yeah I mean it's I mean c doesn't go to escalation I mean I yeah sitting here looking at it I I I don't know I'd need
00:49:12 looking at it I I I don't know I'd need a bit more time to go back and make sure I'm looking at the right data right I mean it's it's perhaps a simpler point that I'm putting to you but do your results here show that uh the differing extent of the routing doesn't affect the
00:49:23 extent of the routing doesn't affect the results materially uh the different extent of the routing uh again from from memory without trying to figure out sort out
00:49:34 without trying to figure out sort out the way these are presented in the table um the more routing uh we did I think the faster it goes to escalation very slightly yeah let's just go to paragraph
00:49:46 slightly yeah let's just go to paragraph 581 then and have a look at that please on page
00:49:51 111 where we have your conclusions as a result of the figures and you say at the bottom the change from fixing condition a to fixing condition B which essentially entails creating additional
00:50:02 essentially entails creating additional routed lines on the inside face of the aluminium panels results in shorter critical times and higher Peak release rates this can be attributed to the fact that the additional routing lines offer additional Pathways for mobilization of
00:50:13 additional Pathways for mobilization of molten PE and more critically because the additional routing lines make it more likely that the inside aluminium skin of the ACM will completely separate earlier in the fire thus making larger surface areas of PE available for
00:50:24 surface areas of PE available for surface flaming increasing fire growth rates and making fire growth to full involvement of the ACM more likely and more rapid I therefore consider that routing of acms with PE filler core is
00:50:35 routing of acms with PE filler core is likely to worsen their overall fire performance in most relevant scenarios that's right I mean that's why we did case b was to check that uh hypothesis yes thank you do you consider that the
00:50:46 yes thank you do you consider that the propensity of the polyethylene core of panels to ignite and to sustain fire growth in the way that you you've observed in your experiments is linked mainly to the delamination of the panels
00:50:58 mainly to the delamination of the panels or some other factor I think escalation of burning of acms is linked to those factors uh in work package
00:51:11 work package one uh our results demonstrated that the ignition of the ACM for our our little 100 by 100 mm squares uh was not very strongly
00:51:23 squares uh was not very strongly influenced by whether they were uh through fixed which would be more representative of a routing condition or rear fixed which would be more representative of a of a cassette condition so in terms of uh the
00:51:35 condition so in terms of uh the prognosis that they will start to burn locally that you will start that you will ignite some PE core uh I don't think it's that significant an issue in terms of the extent to which that fire uh will get big um to use lay language
00:51:48 uh will get big um to use lay language uh I think it is important so no to ignition but yes to sustaining a fire growth uh that's right yes to the the rate at which uh a fire will grow
00:52:05 yes and how would you describe the extent of delamination during the fire at Grandfield Tower once I mean once you have a big
00:52:16 Tower once I mean once you have a big fire
00:52:17 fire um uh the ACM you know it doesn't care once you have a a big fire
00:52:27 big fire uh if you ask me to quantify big I can't do that in any sensible way but once you have once you have a very large external fire plume and you have um fire spreading up the outside of the tower the
00:52:39 the ACM the fire is so big the thermal insult is so intense that the ACM doesn't really care how it's fixed um it has no you know the polythylene is
00:52:50 has no you know the polythylene is coming out at that stage regardless yeah now having covered quite a bit of the ground this morning on this Point looked at in the round would you say that using fixing Case C for 100% polyethylene
00:53:05 fixing Case C for 100% polyethylene ACM uh would allow it to comply with the functional requirement under regulation B4 or
00:53:13 B4 or not I think I mean again never say never my gut instinct is to say absolutely not I absolutely don't agree with that I mean uh regulation B4 requires us to
00:53:26 mean uh regulation B4 requires us to adequately limit the external spread of fire uh if you have acmp used in anything other than in substantial quantities uh I don't think you can be
00:53:37 quantities uh I don't think you can be confident that you've done that as a designer uh so no I disagree strongly with that statement I think that would be a very very dangerous statement to make can I then turn to a slightly different topic which is insulation and
00:53:50 different topic which is insulation and um paraph
00:53:52 um paraph paraphrasing heavily uh you've told us already in your evidence and in your presentation uh that the presence of insulation in the tested systems was critical in facilitating the
00:54:03 critical in facilitating the acceleration of the spread of fire particularly because of its insulating effect that have I got that right that's your your that's right conclusion of a conclusion some yeah the key the key
00:54:15 conclusion some yeah the key the key issue for escalation seemed to be the fact that the opposing faces were insulating if you like yes and and are we also right to understand in general terms that the absence of foil faces on
00:54:27 terms that the absence of foil faces on the insulation gives rise to earlier heat release rates for the polymer foam insulations yes yes and did that have the effect of increasing the uh speed to
00:54:40 the effect of increasing the uh speed to of ignition in the ACM panels no the ACM panels ignited uh long before there was any issue with the insulation right now if the insulation around the windows at
00:54:51 if the insulation around the windows at Grenville had been foil faced on all sides including the cut edges how would that have affected the growth in the heat release rate coming from the
00:55:04 insulation uh if the cut edges I mean that's I think it's impossible to say I think it I mean if if there was no exposed polymer
00:55:18 mean if if there was no exposed polymer foam anywhere within the clading system versus the situation where you have foil facers on the flat faces but you don't on the edge is uh I would not want to
00:55:29 on the edge is uh I would not want to Hazard a guess I suspect that uh I mean my
00:55:33 my gut based only on a gut feeling which is never a good idea in a situation like this uh is to say that I don't think that that impact would be huge I mean could you say with any
00:55:44 huge I mean could you say with any degree of reasonable confidence that that the ignition of the acmpe would have been delayed in any way
00:55:58 for the fire at Grenville Tower yes um I no I don't I don't think
00:56:08 so and is it is it the case that if non-combustible insulation had been used and I use the Expression non-combustible in the reg in the sense
00:56:19 non-combustible in the reg in the sense anticipated by approved document B uh fir spread through the window surrounds would have been delayed
00:56:29 potentially but not not substantially I would say I don't think I don't I I mean again uh you're asking me to to speculate in an area where I've said it's very dangerous to speculate so I'm
00:56:41 it's very dangerous to speculate so I'm a bit uncomfortable with the question but I I you know maybe maybe maybe I know you I'm assuming that if I asked you to quantify
00:56:52 assuming that if I asked you to quantify the maybe I would say that I can't you would say you can't now let's then turn to where we had left off on Monday evening uh and I want to go back to the harmonization uh process in the early 0s
00:57:06 harmonization uh process in the early 0s um can we go back to your paths to grenfell uh report please uh which we will find uh at lb uh lb Y
00:57:20 p2701 and I want to go please to page 117 paragraph 609
00:57:31 Lely thank you and you say here under the heading radar 2 and the quotes transposition unques of European classifications despite these shortcomings UK governments were obliged by the Construction Products directive
00:57:42 by the Construction Products directive to update the relevant guidance and to include reference to the new European classification method however an inter an immediate and wholesale change to the new classification system without a suitably long transition period could
00:57:54 suitably long transition period could have led to Market disruption within the construction
00:57:59 sector uh now uh do I understand it right that in order to do so the research compared and correlated the classifications achieved by the various
00:58:11 classifications achieved by the various different products when tested both to the National and to the European standards that's right well a number of products yes a number of products and if we go please to page 117 uh lower down at paragraph 611 you say there the
00:58:24 at paragraph 611 you say there the stated objective of the study was to ensure that no significant change to the regulatory status quo would occur due to the introduction of the new reaction to fire tests now uh and you footnote that to
00:58:37 tests now uh and you footnote that to 389 Briggs 2002 do you consider Professor that that is significant as an objective for a technical
00:58:49 technical study
00:58:50 study um well I mean it's important to say I mean it's probably important to say that that quote quot comes from Briggs 2002 uh
00:59:01 2002 uh Briggs from recollection was the gentleman who worked for Warrington fire at the time who had been commissioned to perform the radar study I don't know if Briggs was in the room when the decision
00:59:12 Briggs was in the room when the decision to to undertake the work was made so that's that's Brigg's assessment of of what the uh of what the uh objective was um whether that was the objective we
00:59:23 um whether that was the objective we would have to ask Mr Briggs um but
00:59:31 um no that's not a scientific objective that's a that's a if you like that's a political imperative if you like that's not a scientific in is it your understanding that that was the
00:59:42 understanding that that was the objective as you've quoted there uh I can only evaluate it based on the outcome um and the outcome suggests to me that that um that yes um not
00:59:53 me that that um that yes um not disrupting the status quo was important Professor just help me with this the way that paragraph 611 reads suggests that the the approach to the study was
01:00:05 the the approach to the study was circular in the sense that they were assuming the outcome which they were seeking to uh study absolutely all right thank you yes and um my next question but one
01:00:18 you yes and um my next question but one is um did that approach have scientific
01:00:24 Integrity I mean I'm not am
01:00:29 not am I do I have the authority to adjudicate over scientific Integrity I'm not sure well uh I wouldn't consider that a scientific objective and so I would probably have to answer no what would your what would you tell your
01:00:41 your what would you tell your students uh I would say that's not a scientific objective right now let's go please to page 118 next page paragraph one uh 615 615 uh where you uh explain that the
01:00:54 615 uh where you uh explain that the testing data obtained by Warrington fire was used to propose a transposition of the national classifications into the European system and we can see the overall results of the transposition in figure 12 on page
01:01:05 the transposition in figure 12 on page 119 and I think you've taken that from the radar report haven't you as you say there and we've looked at that in in module six in this inquiry is is it right do you agree that in general terms
01:01:17 right do you agree that in general terms the study found that there was no overall correlation between the Euro class system and the UK system that's right and I think the study uses almost almost forbade them those words to describe the outcome what does indeed
01:01:29 describe the outcome what does indeed what does no overall correlation mean uh I guess you you would have to ask the authors I think what what it would mean if we're looking at this
01:01:40 would mean if we're looking at this figure is that all the points lie on a perfect diagonal uh so you would have nothing but a line of points along that diagonal right where you know where you have a one toone correlation a12 NC and
01:01:53 have a one toone correlation a12 NC and so on let's look at it the other way can we go to page 121 then and paragraph 622 of your report here uh and you say uh there um under figure
01:02:04 there um under figure 13 uh however to highlight the lack of true equivalence and you put that in uh italics the lack of true equivalence between the European method and the national class method the guidance noted
01:02:16 national class method the guidance noted that National classification did not automatically equate with equivalent European classifications as shown in figure
01:02:24 figure 14 now what do you mean there by true equivalence uh that if you if you test a a product for instance and you
01:02:36 a product for instance and you achieve um a Class B that doesn't looking at the table above that doesn't necessarily mean that if you tested that product to the National class the British class as it's called in this
01:02:47 British class as it's called in this table that you would achieve class not you might achieve something else or vice versa if you if you tested a product to class not you might not achieve Class B you might achieve class D or worse is true equivalence well what do you mean
01:02:59 true equivalence well what do you mean by true equivalence I just what I essentially mean there's not a onetoone correlation between these between in this table I mean is there any equivalence between at all uh between
01:03:10 equivalence between at all uh between the national and the European classifications there might be a coincidental one can you tell us where well it might it might be that a product that achieves class not does achieve
01:03:21 that achieves class not does achieve Class B or vice versa right um but there's no um there's no scientific reason why you should expect that to be the case it would that would be a coincidental thing
01:03:32 would that would be a coincidental thing you you might get lucky so to speak well just by doing a test under 476 part six and seven and getting a class not uh and then testing it under the European regime it might just happen that you end up with the correspondence working in
01:03:45 up with the correspondence working in that case for that product but you say as you say you might just get lucky I I think you would be very hardpressed to say that the reason that you got the same result is because of Any fundamental physical truths that those
01:03:56 fundamental physical truths that those testing methods have have right interrogated if you like now we know uh following this work that approved document B
01:04:07 document B 2002 carried amendments to recommend that the external surfaces of WS on toall buildings could be either class n or Class B S3 D2 or better yes yes I'm
01:04:19 or Class B S3 D2 or better yes yes I'm summarizing Y what became diagram 40 um and they proposed as an alternative are you able to
01:04:31 alternative are you able to explain
01:04:33 explain um are you able to explain whether there's any Integrity or validity in in that the way you're presenting these two classifications in that
01:04:46 way
01:04:50 I depends what you mean by integrity and validity I mean they are not the same the test methods are different they're interrogating different physics um and the radar reports um and
01:05:03 physics um and the radar reports um and indeed the CC1 1924 contract that was running at around the same time both showed without a shadow of a doubt that there were problems that the correspondents um that they weren't
01:05:15 correspondents um that they weren't equivalent um in approved document B in the revisions uh diagram uh 40 uh as it came to be can't remember if it was diagram
01:05:26 to be can't remember if it was diagram 40 at that stage um we can turn the page if we go to page 122 yeah I mean it it it it sort of it it warns in the footnote uh that these things aren't
01:05:38 footnote uh that these things aren't equivalent um using class notot and Class B as Alternatives within the the diagram I do consider to be
01:05:50 diagram I do consider to be problematic because for certain products uh
01:05:56 uh a class KN and a and a and a for certain products a class KN might be a Class D and if one presumes that the European classification system is intended to
01:06:07 classification system is intended to prevent uh hazards then I think that begs a question how you know how can that be how how can it be that we're demanding Class
01:06:18 Class B uh but we would be happy with class not when class not might be class D you know I there's clearly some there's clearly a problem here for certain products now um if we go to paragraph
01:06:34 products now um if we go to paragraph 617 uh page uh n uh page 119
01:06:40 119 617
01:06:43 617 you um page 120 I think actually is where we find it but the graph is useful you say that whilst it was determined that several of the products which achieved class not in the National classification system achieved Class B
01:06:54 classification system achieved Class B in the European system there were some significant discrepancies um now um what were those significant discrepancies uh I think I mean the paragraph goes on uh I wouldn't be able
01:07:06 paragraph goes on uh I wouldn't be able to tell you exactly what the products were from memory but it goes on and it says for example where foil faced right uh p and phenolic foam insulation products achieve class not they achieve classes D and C
01:07:17 classes D and C respectively um so that I mean that's yeah two cases and why were they significant is really the question why did why is your opinion that the discrepancies you've identified were
01:07:29 discrepancies you've identified were significant be because we if we didn't have the national classification system then we would not accept those products
01:07:41 products um uh if they you know if they turn out to be class D uh we would not accept them because we would we would assume uh that they present too significant Hazard if you're following the so-called linear
01:07:53 if you're following the so-called linear route right is there any or was there any scientific justification as a scientific justification for the proposed
01:08:05 equivalence no I don't I don't think so so was there a justification for the equivalence uh there was a there was a political justification there was a
01:08:17 political justification there was a justification based around the idea that market disruption should be avoided when introducing the European classification system you know the European if if I
01:08:28 system you know the European if if I mean I'm not a lawyer and I you know I'm I'm certainly not a a lawyer with respect to European law on the Construction Products directive but it's my
01:08:37 my understanding that uh the British government was obliged to include the European classification system and that uh in doing so they had
01:08:49 uh in doing so they had to uh or else they would be in violation of the European laws that they had agreed to they they had to come up with an equivalence um they had to uh include
01:09:01 an equivalence um they had to uh include European classifications or the relevant European classifications in approved document being the relevant guidance um uh you know you you they could have
01:09:12 um uh you know you you they could have chosen um class nod is Class C or is class
01:09:16 class D uh or is class A2 or is class A1 you've got to make a choice and it it seems to me that that choice was based around the idea um that market disruption should be minimized that those people who were who were selling
01:09:29 those people who were who were selling products uh and using products on the basis that they were class not should not going forward be prevented from doing so that explains the retention of class
01:09:40 class n but is was there a scientific no I don't uh justification for retaining class n alongside the introduction of Class B which as you've exped no I think there was only a there was only a justification spaced around the idea
01:09:52 justification spaced around the idea that that market disruption should be avoided to the extent possible now um I want you to go with me to what Dr Smith of the BR told us about these
01:10:03 of the BR told us about these discrepancies uh and if we go please to day
01:10:14 235 uh she uh says at page
01:10:21 188 um and she answers my question at line four and I'll put the question I'll show you the question I asked her at line one my point is this or my question is this you knew there was a real risk that a
01:10:33 you knew there was a real risk that a product could achieve class not but not achieve Class B if tested answer there were some outliers but there were a large group where they either achieved better performance or they did achieve Class B question and how was the risk
01:10:46 Class B question and how was the risk presented by these outliers assessed answer it was flagged it was clear that there were outliers you know it was reported in the radar results to the Department question was any error Factor
01:10:57 Department question was any error Factor built into the transposition process to cater for the 208% of outliers you call them outliers but I mean two out of seven answer yeah but I mean they were when you look at the whole grouping for
01:11:09 when you look at the whole grouping for class n in so far as I mean we couldn't alter the classification limits there's no scope to vary those you know you basically had to come up with some kind of correlation and I sat here now don't know how else you could have done it
01:11:21 know how else you could have done it done that
01:11:23 done that because and then she says line 20 before uh given the two regimes are completely different you know you'll never let me turn the page please you'll never going to get 100% correlation
01:11:37 never going to get 100% correlation you're just not now um do you I've shown you that do you consider Professor that the risk presented by the outliers should have been addressed in some way over and above being flagged yes and how would
01:11:49 above being flagged yes and how would that be
01:11:51 that be done by I mean
01:11:58 by asking
01:12:02 why what why are these outliers what are these products what are these products doing that is that is causing them to be outliers you know this is something that we see time and time again in this
01:12:14 we see time and time again in this evidence uh where are the people who are asking
01:12:19 asking why I I just I just I struggle to understand the lack of inquisitive uh around you you have two
01:12:30 uh around you you have two classification systems based on different tests they're giving you substantially different results the differences between those two results generate a potential Hazard within the building regulatory system why what is the building
01:12:43 system why what is the building regulatory system missing what are the behaviors what are the factors mechanical thermal chemical whatever that are causing causing these differences in Behavior Uh it's completely absent from this conversation
01:12:55 completely absent from this conversation the question of why and if somebody had just asked why uh then I don't think we'd be here so is it the case that you wouldn't propose simply building in some
01:13:07 wouldn't propose simply building in some kind of error Factor some kind of margin for error into the exercise of transposit of um transposition you would investigate why these were outliers maybe that would
01:13:18 these were outliers maybe that would have been an answer maybe building in some conservatism into the transposition uh would have been an answer uh you know maybe going for A2
01:13:30 answer uh you know maybe going for A2 instead of B I don't know um but the to get to get to that conservatism to build that conservatism in you would have to
01:13:41 that conservatism in you would have to ask why you would have to understand why these specific products are behaving in this specific way and only then could you know with any certainty that the
01:13:52 you know with any certainty that the conservatism that you've built in is actually sufficient is actually going to going to eliminate these hazards to the extent that you can you know I just um
01:14:03 extent that you can you know I just um yeah you could have you could have done that but you would have have to you would have had to understand what was going on you would have had to ask the question and there's i' I've seen no evidence that anyone really did it seemed that people sort of shrugged
01:14:15 seemed that people sort of shrugged their shoulders and said this is the best we can do yes now Mr chairman we haven't quite finished this line of examination but it will take a little longer than five minutes I think to finish not much
01:14:26 minutes I think to finish not much longer but a little bit longer than five minutes to finish well I'm in your hands Mr mil would you uh would you like to stop there no I think let's let's I would I would like if I may to finish it if it's possible we can and I'm sure
01:14:37 if it's possible we can and I'm sure that Professor bis can C with another five minutes that's fine yes um now um there's another aspect of the radar 2 testing then that I want just to explore with you um uh Dr Smith was uh examined
01:14:49 with you um uh Dr Smith was uh examined about some comments that she'd made in a Brack Part B working party meeting on the 10th of May 2001 uh H H and let's just have that up it's CLG
01:14:59 CLG 47308 please page 7 paragraph
01:15:05 5.7 the panel has seen this before a number of times during module 6 and uh Dr Smith was on the panel in an advisory capacity and underneath radar 2 reaction
01:15:17 capacity and underneath radar 2 reaction to far top of your screen she's recorded as saying this Dr Smith explained that for radar 2 there had been 60 60 back-to-back BS and PR n tests with wide variations in results Dr Smith explained
01:15:29 variations in results Dr Smith explained that one problem was that there was an uneven distribution of products submitted for testing since pii is 50% industry-led industry sent in the products that it wanted to send in there
01:15:40 products that it wanted to send in there is a natural reluctance by industry to put in poor performing products uh now she was asked uh and I'll just give the reference date 235
01:15:51 I'll just give the reference date 235 page 179 line 20 whether to her knowledge at that time
01:15:58 time um the the radar work or the meeting considered whether the data set used to transpose National classes to Euro classes was fairly representative of what was on the market in the United Kingdom at the time that was what she
01:16:09 Kingdom at the time that was what she was asked and in summary her her evidence was that she thought there would have been discussions and my question for you is should the representativeness of the product submitted for testing have been a
01:16:21 submitted for testing have been a material consideration in a study of this kind
01:16:26 this kind I I believe so yes in other words should there have been an examination of whether for example some of the outliers that Dr Smith
01:16:35 Smith described might be the most commonly used products on the market yes and is there any other reason why there should have been a an examination
01:16:46 there should have been a an examination of the why question I
01:16:51 mean if it's your if it's your job uh to to write building regulations uh then then you need to make sure that
01:17:02 then then you need to make sure that what you are doing is representative of what is happening in the world and if you don't then you're not doing your job um then let's go against that background to approved document
01:17:14 background to approved document B which if we go to page 122 of your report if we can just get back to your report please that's the path to the path to Grandfield report at lb y p270
01:17:25 path to Grandfield report at lb y p270 one page 122 you can see diagram 40 that we looked at earlier um we didn't examine the footnote note one let's do that if we can have that expanded please so that everybody can see it clearly uh
01:17:37 so that everybody can see it clearly uh I'll read it to you it says if we can expand that thank you the national classifications do not automatically equate with the equivalent European classifications therefore products
01:17:48 classifications therefore products cannot typically assume a European class unless they have been tested accordingly now looking at the words do not a automatically equate do they equate at all in your
01:17:59 all in your opinion I mean as I've said maybe sometimes by
01:18:04 coincidence is it technically accurate to to refer to the equivalent European
01:18:13 classifications I mean given that it says that they don't automatically equate then I agree with you you you the immediate use of the word equivalent is a bit in congruous yes well as a matter of language one can one can debate that
01:18:24 of language one can one can debate that of course but are would you say uh that class B is equivalent to class not it uh I mean in reality no when you
01:18:35 not it uh I mean in reality no when you say in reality do you mean in terms of how in terms of how we would expect a product to react in the case of fire then no thank you but they're not they're not even conceptually the same are they because the tests are
01:18:46 are they because the tests are different that's right yeah yeah so um to talk in terms of equating whether automatically or otherwise to equivalent European
01:18:58 otherwise to equivalent European classifications ones using language which suggests that they are conceptually uh that they may conceptually equate in some circumstances whereas as you've already
01:19:10 circumstances whereas as you've already said they may equate but only by a matter of coincidence and not not conceptually at all that's right I mean I I I I would read this language as saying the the uh European
01:19:23 saying the the uh European classifications that are deemed by radar 2 to be equivalent as opposed to the fact that they actually are if you see what I
01:19:32 mean yeah one one I mean one could argue that radar 2 had deemed them to be equivalent in a way in their table uh I mean obviously there's no true equivalence in in physical terms
01:19:49 yes yes yes now um then finally this topic page 254 of your report paragraph
01:20:03 1584 you say this when the harmonized European reaction to fire testing standards and classification system which was also developed based on a reference scenario linked to the growth of Fire Within A compartment rather than
01:20:14 of Fire Within A compartment rather than on the outside of a building where introduced in 2002 government again opted to retain the status quo rather than revisiting or shelving the standards of performance that they had
01:20:26 standards of performance that they had until then apparently considered appropriate for cladding the external wall indeed the new European system was imprecisely benchmarked against the existing National classification system enabling the use in England of certain
01:20:39 enabling the use in England of certain composite products that would not be considered permissible under the European system in the context of meeting its European obligations whilst not disrupting the status quo by placing new constraints on English industry for
01:20:51 new constraints on English industry for government this decision was a technical solution to a PO itical problem in your opinion Professor could the European system have been more precisely benchmarked against the national
01:21:03 classes was it possible probably not it could have been more conservatively benchmarked against the European system
01:21:14 the European system but you the the idea that you could somehow make two different sets of tests interrogate precisely the same physics is I think unlikely and is it your
01:21:26 is I think unlikely and is it your opinion that the national standards should during this period at the very least have been Revisited if not shelved absolutely Mr chairman is that a convenient moment is it have you got to
01:21:38 convenient moment is it have you got to the end of your topic yes then it is thank you very much yes well we will now have a break Professor bis we'll stop there we'll resume at 20 to 12 please and again please don't discuss your evidence while away from the room
01:21:50 evidence while away from the room certainly thank thank you very much
01:22:02 thank you Mr minute 20 to 12 please
01:22:23 okay
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01:41:11 uh would you ask Professor Bisby to come back in please
01:41:26 right Professor Bisby ready to carry on yes thank you thank you very much yes Mr yes thank you very much uh Professor I now want to ask you about BR 135 and specifically desktop assessments uh I say thereunder but in
01:41:39 assessments uh I say thereunder but in relation to the criteria uh and for that youve produced a report that is now already in evidence of the 30th of May this year 2022 and that is LBP 2604
01:41:54 there it is uh could we go please to page8 paragraph
01:42:00 39 and we can see the your instructions please comment on the extent to which you consider that undertaking a desktop study to assess a proposed external wall arrangement for a building over 18
01:42:11 arrangement for a building over 18 meters in height against the criteria in BR 135 is a valid and appropriate method by which to establish the compliance or otherwise of the external wall arrangements with the functional requirements in B4 or of the building
01:42:23 requirements in B4 or of the building regulations and you say you consider this request as two distinct Parts yes uh and you draw a distinction between assertion uh and establishment yes yes
01:42:36 assertion uh and establishment yes yes yes now um let's uh look at the criteria first if we go piece to page 26 and paragraph 188 of this report you tell us and today remind us I think that
01:42:50 tell us and today remind us I think that b135 doesn't set past criteria um but only means by which systems can be shown to have failed yes that's right and the BSA 414 and classification to
01:43:01 and the BSA 414 and classification to b135 can only ever show that an external wall Arrangement is inadequate it doesn't show that it's adequate for the purposes of compliance with um B4 of the
01:43:12 purposes of compliance with um B4 of the of the regulations that's my view yes now if we go back um just briefly to the the other report the the path to grenfell report at LBP 270
01:43:25 1 and go please to page
01:43:35 42 paragraph 207 there on the screen in the middle you say this the extent to which the pass criteria you use the word pass in in quotation marks in b135
01:43:47 pass in in quotation marks in b135 represent conservative assessments of the performance of external wall and cladding systems as regards the likelihood of such systems leading to unacceptable external upward vertical far spread when applied on real
01:43:58 far spread when applied on real buildings is very difficult to assess quantitively as far as I'm aware this question has never been explicitly addressed in any BR or BSI Publications on this matter this is to say that I'm
01:44:09 on this matter this is to say that I'm not aware that the real world rationale for the chosen performance criteria in BR 135 have ever been clearly articulated uh uh My Hope Is that such
01:44:20 articulated uh uh My Hope Is that such questions can be addressed bya witness statements Etc and You' had you could say footnote 886 at the foot of the screen this is not to say if we go to the foot of the screen foot of the page foot of the
01:44:31 foot of the page thank you sorry foot of the page footnote 86 this is not to say that the rationale for the performance criteria cannot be
01:44:39 cannot be inferred
01:44:42 inferred uh is it
01:44:44 uh is it correct uh that having followed the re relevant evidence in module six of this inquiry it's your opinion that the rationale for the selection of the performance criteria in b135 remains
01:44:55 performance criteria in b135 remains largely unarticulated and
01:44:59 unexplained um yes I mean a number of witnesses I think as I explained in the in the in the um v135 desktop assessment report that I've
01:45:10 that I've submitted uh a number of witnesses uh notably Colwell Martin and Smith I believe uh sort of commented on various aspects of the performance criteria uh
01:45:22 aspects of the performance criteria uh none of
01:45:24 none of them at least in my assessment sort of were very clearly articulated yes this is exactly what it was and this is who decided this I was sort of left
01:45:36 left um you know all all of those Witnesses seemed to sort of say you know there will there will have been discussions uh and there will have been people who expressed a view but that nobody seems to have known who those people necessarily were are you able from your
01:45:49 necessarily were are you able from your researches independently of the evidence of those witnesses to throw any light
01:45:56 light on the the origins of the criteria in BR 135
01:46:04 135 um I mean this is something that I've thought quite hard about and was thinking about um throughout my work for the inquiry when we think about BSA 414 testing and the various criteria that are applied I think there's an obvious
01:46:16 are applied I think there's an obvious question why you know why why uh why 5 m above the hearth for the temperature why 600° why 30 seconds um uh you know
01:46:28 why 600° why 30 seconds um uh you know why 9 M for the rig why no windows all sorts of questions that we've talked about uh to some extent over the past few days um the the the the I mean the only the only
01:46:41 the the the the I mean the only the only thing that hasn't come up in module six from the witnesses where I think there may be a link which is what I had assumed the link was but none of them mentioned it so I may well be wrong was that some research that was done looking at the effectiveness of spandrel panels
01:46:53 at the effectiveness of spandrel panels to prevent external fire spread um this is the langon Thomason Law uh paper uh and work that came up I can't remember when at some point within the past week
01:47:04 when at some point within the past week or so um I think Professor Terrero mentioned it in his evidence um last week um and that work was looking at um the extent to which uh non-c combustable
01:47:18 the extent to which uh non-c combustable uh or fire resisting spandrel panels should be demanded essentially the question of whether or not you can have a floor to sealing window or do you have to have a an inert bit of the building above every window or in between Windows
01:47:29 above every window or in between Windows on a building or do you need to have um protrusions uh balconies if you like uh that come off the building in order to prevent story to story fir spread recognizing that um in the absence of
01:47:42 recognizing that um in the absence of each of those things you might get fir spread from window to window there was a significant research program was performed um and the the conclusions of it
01:47:53 it uh I'll prob I'll get the words wrong but the conclusions of that work essentially were that uh whether you had a spandrel panel or not um you would get fires spread from story to story in
01:48:05 fires spread from story to story in those experiments in up to 15 minutes um I believe were the words that they used and so there you know there's a 15 minutes that kind of pops into the psyche of the
01:48:17 psyche of the community um and that 15 minutes is in the BR 135 criteria the limiting temperature 615 minutes um 5 m above the Hearth uh and that's the only kind of
01:48:29 Hearth uh and that's the only kind of technical basis that I've ever been able to find for the 15 minutes beyond that I have to take the witnesses at their at their word now if we go please to page 25 of uh your uh uh report
01:48:47 please um you uh sorry I'm so sorry your desktop report that's
01:48:55 that's lby
01:48:59 p264 page
01:49:04 25 you say there at paragraph 184 as follows um that you note that b135 does not set any performance criteria for mechanical performance uh it simply states that
01:49:17 performance uh it simply states that ongoing system combustion following extinguishing of the ignition source shall be included in the test and classification reports together with details of any system collapse spoiling delamination flaming debris or pool
01:49:31 delamination flaming debris or pool fires uh now uh the the words should be considered as part of the overall risk assessment when specifying the system uh is what follows next and you
01:49:42 system uh is what follows next and you go on to explain that in paragraph 185 to 187 over the page
01:49:53 uh and at 186 you you quote from Dr colwell's
01:49:59 colwell's evidence uh as you can see she says in in the context of the mechanical response it was so system dependent that setting a criteria sick for that was to
01:50:10 setting a criteria sick for that was to be found was was was found to be in a standardization process something that couldn't be achieved and even today in the later most recent work in this area by other bodies that performance value still has not been formalized it's a
01:50:21 still has not been formalized it's a quite a technical challeng I note that the above statement is factually inaccurate the UK loss prevention standard LPS 1581 and the as5 13 large scale clading test standard
01:50:33 13 large scale clading test standard both of which are based on testing to BS 8414 incorporate criteria for mechanical performance Andor the generation of falling and or burning debris in the light of that is there any
01:50:46 debris in the light of that is there any scientific reason why such criteria could not have been or cannot be introduced into BR 135 no I mean I I I would agree with Dr
01:50:58 135 no I mean I I I would agree with Dr colwell's characterization of it as challenging given the range of systems and products that might be used um and given uh some need if if one was going to do that one would have to somehow
01:51:10 to do that one would have to somehow Define what adequate looked like uh and that would that is a not insignificant challenge but it's not impossible it could have been done it has it indeed it has been done for
01:51:21 has it indeed it has been done for instance as511 3 has criteria as 5113 is a more difficult um uh a more difficult test to pass as a consequence of those criteria
01:51:33 pass as a consequence of those criteria so systems that would pass a BSA 414 b135
01:51:36 b135 classification not withstanding my comments about pass should always be in quotes when we have these conversations um uh would not pass an as 5113 uh in some
01:51:48 5113 uh in some cases turning to the question of desktops specifically let me see if I've understood your opinion and please correct me in at any stage if I've got this wrong Professor but does it work like this um your basic
01:52:00 but does it work like this um your basic thesis is that meeting the functional requirement whether via ADB or via b135 specifically within ADB or or otherwise requires a wide range of subjective
01:52:13 requires a wide range of subjective assessments for which there is no objectively identifiable body of matching
01:52:19 expertise um
01:52:25 I I uh can you give that to me one more time I want to make sure it's the last bit I want to make sure that I agree with right uh is it your basic thesis that in in in meeting the functional requirement somebody uh has to do uh a a
01:52:40 requirement somebody uh has to do uh a a potentially w a wide range of subjective assessments yes I mean that is uh as I've as I've said in in my report
01:52:55 um subjective judgments uh in the absence of full and complete knowledge I.E subjective judgments in the absence of knowing the truth of the
01:53:06 truth of the matter um that that is what engineering is you know we we we every day make decisions on the basis of incomplete information and we have to rely on our professionalism and our competence in order to do that that's what we do and
01:53:19 order to do that that's what we do and given the potentially wide range of subject assessments is it correct that it's your opinion that there is no uh no body of matching expertise which can be objectively identified you can't point
01:53:31 objectively identified you can't point to a pool of expertise out there and say that expertise is what is needed to no no I mean I couldn't clearly point to that pool of expertise no so it does it
01:53:43 that pool of expertise no so it does it come to this that even if you tested your intended system and you met the BR 135 criteria performance criteria using the Lang language of
01:53:54 the Lang language of 12.5 of
01:53:55 12.5 of ADB that would not automatically guarantee that you would achieve the outcome required by regulation B4 because of the differences between a test and the real world application of
01:54:07 test and the real world application of the thing tested that's right there is in in my view um uh and as we discussed the other
01:54:15 the other day based on my reading of br-135 I think it's br13 5's view as well uh the the the competent professional the designer whoever that is must assess
01:54:29 designer whoever that is must assess whether or not the result from a br 135 classification in a lab on a bs8 414 rig is applicable to a real building out there in the world they must do that um that that I mean that's yeah anyway
01:54:41 that that I mean that's yeah anyway sorry yeah no no keep continue no that's it I'm right finished so I think it follows from what you just said that that somebody always has to do some kind of expert assessment which you might
01:54:52 of expert assessment which you might call a desktop some kind of uh scientific assessment even on the system that has been tested uh and has met the criteria that's right yeah and what what
01:55:04 criteria that's right yeah and what what I was going to say which is relevant in my last answer um is that's why it is so important that we um we Society people
01:55:18 important that we um we Society people who rely on the safety of buildings that's why it's so important we we can identify who that person is who is that person who has made that decision and that person Bears the responsibility and
01:55:29 that person Bears the responsibility and they bear the liability for having taken that decision and if we can't identify that person then uh in a way we get what we deserve if we don't choose to make sure we can
01:55:40 if we don't choose to make sure we can identify that person I'll come back to the that person issue in in just a second but is it the case also that when you do a
01:55:50 you do a desktop in lie of a test and assessment in lie of a test based on test data from other tests that the gap between the
01:56:01 other tests that the gap between the conclusions reasonably available from that test data and the real world application widens further requiring even more or greater judgment from the
01:56:12 even more or greater judgment from the the person uh I would expect it to yes and is it your opinion that the fundamental or a fundamental problem with the regulatory regime uh I I I in the building regulations so
01:56:25 uh I I I in the building regulations so far as external fires spread is concerned is that it is premised on the availability of of a pool of expertise that has never existed um for for many of the
01:56:38 existed um for for many of the assessments I think that's probably true yes I mean it it may be that for a very very small number of uh small extensions
01:56:49 very small number of uh small extensions of existing assessments one could I think inedibly argue in favor of that but I think by and large um uh I think the community's
01:57:00 um uh I think the community's understanding of the relevant physics and the factors at play is is inadequate yes and is the problem
01:57:08 problem exacerbated is this part of your thesis that the problem is exacerbated by the fact that BR 135 as we discussed on Monday in any event does not cover the entire ground occupied by the functional
01:57:21 entire ground occupied by the functional requirement that's part of the argument yes yes now let's then go into your report please page nine paragraph
01:57:34 48 uh you say there uh and you quote from your regulatory testing and Pastor grenfell
01:57:42 grenfell report at paragraph
01:57:46 48 uh and uh you run down to paragraphs 50 and 51 with two questions in question 1.1 is a desktop assessment a valid and appropriate
01:57:57 assessment a valid and appropriate method to establish whether a given external wall Arrangement would meet the requirements of b135 if it were tested in accordance with BSA 414 part one or two in lie of actually performing the
01:58:08 two in lie of actually performing the BSA 414 tests and assessing the resultant data in accordance with b135 and then question 1.2 to what extent it is is it valid and appropriate quotes unques to assume that meeting the
01:58:20 quotes unques to assume that meeting the the requirements of b135 by desktop assessment or indeed by testing to bs8 414 is sufficient to demonstrate compliance of the external wall arrangement with functional requirements given in B4 of the building regulations
01:58:32 given in B4 of the building regulations so those are the questions now if we go back to paragraphs 44 and 45 please on the previous page page
01:58:43 eight at the foot of the
01:58:48 screen uh can you tell us what do you understand to be the regulatory basis on which a designer who can validly assert that an external wall Arrangement would
01:58:59 that an external wall Arrangement would meet the B the requirements of BR 135 would be entitled to do so without establishing the fact through a
01:59:08 test
01:59:12 um I I mean I guess I would go back to the building act 1984 uh and I I mean I'm not as as I've said a number of times I'm a lawyer um
01:59:24 said a number of times I'm a lawyer um uh and and it's clear to me that I don't understand the inner workings of the law um more so every day uh as it happens uh but it's my understanding that in our regulatory system in the United Kingdom
01:59:35 regulatory system in the United Kingdom that anyone can do anything they want uh there is no requirement for anyone to follow any particular rules ever under any
01:59:44 any circumstances uh they can choose to meet the requirements of the approved document in some other way any other way now and as as you told us a test an actual test under BSA 414 is just a test
01:59:57 actual test under BSA 414 is just a test and there's always a difference between the test and real world use operational use yes unless you happen to be building a BSA 414 test rig yes indeed but a real but in the in real
02:00:11 yes indeed but a real but in the in real life a BS 8414 test rig does not comprise the entirety of an external wall in any building absolutely as we established on Monday is it your opinion that the framers of ADP decided that the
02:00:23 that the framers of ADP decided that the results of a successful test under BSA 414 which met the performance criteria under under BR 135 would sufficiently and reliably indicate the outcome under
02:00:35 and reliably indicate the outcome under B4 in real operational use namely meeting all of the elements of the functional
02:00:42 requirement I well I mean I I can't speak obviously I can't speak for those people who did frame uh ADB um but
02:00:53 ADB um but um whether it's in bs8 414 or b135 or ADB I can't remember right now but uh there is a statement somewhere in there in one of those documents that uh for
02:01:05 in one of those documents that uh for instance achieving a classification with respect to v135 in accordance with testing or indeed desktop study um doesn't
02:01:16 doesn't address uh fir spread from building to building for instance so there there are certain requirements of B4 that it simply doesn't address so somebody has to make that assessment in order to assure that B4 is being satisfied I mean
02:01:27 assure that B4 is being satisfied I mean that would be one example of would another be use and you'll recall the words in B4 having regard to the uh height position and use of the
02:01:39 height position and use of the building um in in in so far as one has to I think yes is the answer to your question in in so far as one one has to look at the
02:01:50 so far as one one has to look at the outcome of a BSA 414 test one has to look at
02:01:55 look at the uh failure criteria of a br 135 classification and then as a as a competent professional as a designer one has to ask oneself if the use of one's
02:02:09 has to ask oneself if the use of one's building is commensurate with the outcome uh or with the with the assessment of adequacy that's been used in the in in the BR 135 classification yeah you have to you have to say Okay
02:02:20 yeah you have to you have to say Okay well this is this is what has been deemed adequate with respect to BR 135 what does that represent with respect to my building is those are the kinds of questions that we expect professionals to ask themselves yes yes does
02:02:31 to ask themselves yes yes does that answer tell us that there's nothing in BR 135 itself the criteria which are met Let It Be assumed uh which would take account of the of the use of the
02:02:44 take account of the of the use of the building
02:02:46 building um no no no it doesn't say if your building is a high residential building this is what's acceptable and if your building is a shopping center this is what's acceptable no it doesn't do that
02:02:58 what's acceptable no it doesn't do that nor nor indeed would this be right that there's anything in b135 that tells you how you should interpret the results in the light of the occupancy profile of the building who you have in it certainly not no is it your opinion that
02:03:10 certainly not no is it your opinion that meeting the performance criteria under b135 on the basis of full scale test data achieved from a BS 8414 test would mean that you've always achieved adequate resistance to spread of fire
02:03:21 adequate resistance to spread of fire under B4
02:03:22 under B4 having regard to the height use and position of the building absolutely not so even successfully meeting the performance criteria under BR 135 could never provide a complete answer as to
02:03:33 never provide a complete answer as to whether your external wall buildup met the functional requirement I think that's right no absolutely not so the build just to be clear the building designer would still need to go on to investigate whether the wall build up
02:03:44 investigate whether the wall build up would
02:03:46 would adequately that's the word in the in the functional requirement adequately resist the spread of fire having regard to the position and intended use of the building and the height too indeed I mean even even if a designer chooses to
02:03:59 mean even even if a designer chooses to follow the so-called linear route they need to do that no matter what they do they need to do that so if a test of a system under bs8 414 is as you put it just a test then
02:04:11 414 is as you put it just a test then it's is this right it's not even a test the results of which would satisfy the entirety of the functional requirement for that system no so do you agree that that meeting the
02:04:22 no so do you agree that that meeting the BR 135 performance criteria even with test data on the very system you intend to
02:04:28 to build doesn't get you home under b41 because you've still got to apply a subjective assessment to the other aspects of the functional requirement such as the position of the building or
02:04:39 such as the position of the building or the use of the intended use of the building Absolut yeah but but even I mean even even more than that and perhaps I think more importantly with respect to some of the issues we're talking about you you have to decide how
02:04:51 talking about you you have to decide how much
02:04:52 much if you like to use lay language you have to decide how much your building looks like a bs8 414 rig and how the differences between those two things might change the outcome For Better or For Worse and did is it also your opinion that the
02:05:05 opinion that the assessment uh should extend uh to whether the the outcomes of a BS 8414 test to to b135 criteria support the far
02:05:18 test to to b135 criteria support the far strategy if there is one for that building or not yeah and I I mean I think that's the point uh that that Professor Terrero made very well um the other day in his presentation and those are the considerations that we expect
02:05:30 are the considerations that we expect from competent professionals who are designing real buildings out there in the world um you have to look at the the way the test is performed you have to look at the assessment criteria that have been used to to to to classify the
02:05:41 have been used to to to to classify the system and you have to decide whether or not those all of those things um are in line with your overall fire strategy for your building and and and the extent to which the adequacy that's been assessed
02:05:53 which the adequacy that's been assessed will actually be adequate in your building given all of the ways you've addressed um functional requirements B1 B1 through B5 yes now we we in the last run of questions and answers our
02:06:05 run of questions and answers our exchanges Professor we've covered quite a wide range of subjective assessments which I think in your opinion must be applied not withstanding uh that you can assert uh
02:06:16 withstanding uh that you can assert uh that uh your build your W buildup would comply with or would meet v135 criteria if
02:06:24 if tested uh and even if in fact tested uh what is the pool of expertise or what was the pool of expertise out there in the market between 2012 and
02:06:38 there in the market between 2012 and 2017 do you mean do you mean who had the expertise that could be applied to these questions
02:06:46 questions yes
02:06:49 um there would be people people who come from the well I mean so the people who were working in the test houses the people who run BSA 414 tests will have had some experiential
02:07:01 had some experiential understanding uh some kind of puristic knowledge of uh what types of you know they will have seen a number of experiments or a number of tests rather
02:07:12 experiments or a number of tests rather uh and they will observed the outcomes they will have observed the types of behaviors that were exhibited by different products and systems when assembled in different ways and they will have had some knowledge um based on that experience and then you'll have
02:07:24 that experience and then you'll have people out there in in the in the fire science and Consulting world who will have some technical understanding of fire science and fire Dynamics and the relevant physics the way things burn all of these
02:07:35 of these issues um uh so there's there's people out there in the world who had all sorts of different um types and amounts of knowledge did did they
02:07:46 knowledge did did they coales
02:07:48 coales no I don't and I would I would say not I would say
02:07:53 would say not but unless they cares how
02:07:58 cares how would the necessary subjective assessments be carried out in practice well uh as I've and I've
02:08:09 out in practice well uh as I've and I've labored the point I think quite heavily in the introductory sections of my my my report on on these issues you know I I've never done a br 135 desktop report
02:08:20 I've never done a br 135 desktop report uh I should think I would agree to do it based on my assessment of the available knowledge uh all I can tell you is that having looked at um the six specific desktop study reports that I was looked
02:08:32 desktop study reports that I was looked I was asked to look at in generating this report as well as a number of others that I've looked at over the years that I've been involved uh with the inquiry uh is that that knowledge base was not good um is probably the only way
02:08:44 was not good um is probably the only way I could characterize it it was um insubstantial let's put it that way let's then go to page 39 of your report paragraph
02:09:01 287 and you say there and this comes back to a point we've covered briefly uh just a little earlier you say taken together the building act 1984 the building regulations 2010 and and
02:09:13 building regulations 2010 and and approved document B very clearly in my opinion permit the use of desktop assessment permit the use of Assessments in lie of tests do you say that that extends to the external wall
02:09:25 buildup yeah I mean I mean if you I mean thinking as broadly as we can about Assessments in lie of tests as I've said that's that's engineering engineering is one gigantic assessment in lie of test
02:09:37 one gigantic assessment in lie of test right now you say very clearly in my opinion permit the use of Assessments in Le of tests are you able to point to any particular wording in the act or the regulations or approved document B that says that you can use Assessments in Li
02:09:49 says that you can use Assessments in Li of tests for an external wall Construction ction no so what is the basis on which you say that taken together those three elements the act
02:10:00 together those three elements the act the regulations and approved document be very clearly in your opinion permit the use of Assessments in Le of tests because I I take the view that taken together those documents permit you to do anything an an assessment in in L of
02:10:12 do anything an an assessment in in L of test is simply something right it's a I follow so in essence it's your understanding of the permissive nature of the regulatory regime that's correct
02:10:23 now if we then go to paragraph 109 please sorry yes paragraph 109 page 17 of your
02:10:32 of your report you uh quote from ADB paragraph 12.6 there and these are now familiar words I W read them out um have you
02:10:43 words I W read them out um have you considered when you formed your opinion how that language could support the use of Assessments of an external wall build up in Li of tests I think it doesn't does it
02:10:55 it um no
02:10:57 um no but no I mean doesn't say anything explicit about Assessments in Li of tests but I don't I don't necessarily think it's obliged
02:11:06 to so to be clear you don't get this permissive uh Liberty from any wording within ADB or indeed within the regulation or or within the ACT it's a
02:11:19 regulation or or within the ACT it's a an glomeration of of all three which create a permissive regime which allows you to approach the matter in the way you've
02:11:26 you've described is that right yes I mean there I mean as I as I cover in the report um there is uh in one of the appendices of ab there are some statements about um
02:11:37 ab there are some statements about um Assessments in Le of test uh and and and the permissibility thereof if you dig down into the words and and I mean if you want to if we want to go into the
02:11:49 you want to if we want to go into the the literal words we could argue about this specific words used in the specific references to other types of documents that
02:11:55 that support um Assessments in lie of tests that are provided within that appendex and and as I've done in my report I've gone through that quite carefully and sort of said well um despite the fact
02:12:06 sort of said well um despite the fact that this appendix of ADB does highlight Assessments in Le of tests as being um permissible for various types of fire tests both fire resistance tests and reaction to fire tests it then
02:12:19 reaction to fire tests it then specifically calls out a number of other documents uh uh and none of those specifically called out documents are specific to external wall Assessments in
02:12:32 specific to external wall Assessments in Le of test so you you could I guess one could argue that by exclusion ADB actually says the opposite of that they're okay but my
02:12:45 of that they're okay but my overarching um I mean we could argue about those the specific words all all day of course but my over arching view is the broad view that regardless of what an appendix and approved document B
02:12:57 what an appendix and approved document B says that um a designer in the United Kingdom is permitted to do whatever a designer wants to do and provided that they can get someone in the building
02:13:09 they can get someone in the building control uh system within the process of having their designs approved to agree with them then that is all that they are required to
02:13:19 do by our system of Regulation so if you know if someone wants to do a if someone wants to do a a desktop assessment of the external wall assembly they are free to do so in my view regardless of
02:13:31 to do so in my view regardless of whether ADB explicitly says it um ADB I mean I the opposing view of course would be you know ADB doesn't say that you can't do it um and nor nor does the the
02:13:43 can't do it um and nor nor does the the law the building regulations or the building act but if if I've understood you correctly you're really I think resting your view on the fact that the functional requirements in the
02:13:55 the functional requirements in the building regulations are what they are and there is no prescriptive way of satisfying
02:14:08 them yes yes I mean if you in so far as you have to demonstrate compliance which I imagine means to the building control body
02:14:21 building control body you there is no one way or indeed any prescribed way of achieving that and therefore if you can put before the building control
02:14:32 building control body a sufficiently persuasive uh we'll call it a desktop assessment but I think we both know what it involves yeah that is
02:14:43 it involves yeah that is sufficient uh yes um and you know I would also say that that is always um the case as I've said whe even
02:14:55 always um the case as I've said whe even if you were to follow even if you were to go through 125 through 129 follow all of those rules with apologies to Mr Millet
02:15:06 Millet um uh you would you would still in my view um be the person who is expected to have made an assessment as to whether or
02:15:17 have made an assessment as to whether or not that is an appropriate course of action right I think I think I mean as I say I'm not a lawyer but that is that is how I read those documents right thank thank you very much yes now looking at
02:15:29 thank you very much yes now looking at you mentioned 12.5 12.5 to 12.9 and the so-called
02:15:35 so-called rules um the text is on the screen in front of us um did did you consider or have you ever considered whether if you were to meet the the guidance under 12.6 to
02:15:47 12.6 to 12.9 which would include diagram 40 and 12.6 or the um MC requirement for 12.7 for
02:15:56 for insulation you could do that by an opinion that a product for example like an external wall panel would satisfy class n or Class B if tested but in the
02:16:09 class n or Class B if tested but in the absence of a test so it's a very interesting question it never crossed my mind until recently uh uh uh and based on what I've
02:16:21 recently uh uh uh and based on what I've said yes you could based on what I've said
02:16:27 yes and that would have to follow wouldn't it if you were going to have desktops based on the alternative uh which is BR meeting br1 135 criteria the same must apply in
02:16:39 135 criteria the same must apply in relation to a putative class n panel that's
02:16:48 right have you ever come across in your work for this inquiry or otherwise any case where somebody used a desktop assessment in order to assess what would happen to a particular external wall
02:17:00 happen to a particular external wall panel or piece of insulation which hadn't been
02:17:09 tested I mean maybe maybe the um but you haven't seen one well maybe I have uh well I've not seen the desktop but i' I've seen maybe we've seen the outcome
02:17:21 I've seen maybe we've seen the outcome of that having been done uh the I mean for instance the I think it's a BBA the BBA certificate I think for conic forab Bond I believe uses the
02:17:32 for conic forab Bond I believe uses the terminology something to the effect of maybe considered class not uh maybe that's what's happened there but you you right but I've not seen anyone write a report that says that's what's happened that's that was
02:17:43 that's what's happened that's that was really my question but thank you for thank you for clarifying
02:17:48 that uh now um let's go please to paragraph 216 of your uh report please uh which we'll
02:17:59 uh report please uh which we'll find uh on um forgive me um page
02:18:07 um page 30
02:18:09 30 competencies uh and this is a long passage uh although it's headed competencies and is immediately followed by qualifications on the next page um you set out in this report some
02:18:20 you set out in this report some criticisms that you make of the institution such as the pfpf for not rigorously laying down clear and high standards have I I summarized or perhaps over summarized your
02:18:31 your opinion but is that right yeah well for not I mean yes sure for not laying really laying down any standards
02:18:46 right is it um have you consider the possibility that one reason why um those standards don't lay down a rigorously
02:18:58 standards don't lay down a rigorously clear set of high standards is because there was not a demand for it have you have you looked into that you mean that out out there in the world of practice nobody was demanding it correct uh I
02:19:10 nobody was demanding it correct uh I think that I think that must be true I don't know but I think that must be true right why must that be true because of the nature of all of the desktop reports that I've been asked to
02:19:21 desktop reports that I've been asked to review right now turning to those I think you offered a detailed critique of six desktops for six separate external W buildups done after 2014 yes um more detailed for some than for others but
02:19:32 detailed for some than for others but yes I looked at six reports indeed and and just summarizing those we've got the the um one done by BR for total facade Solutions of the 29th of June 2015 which we looked at with Steven Howard of the
02:19:43 we looked at with Steven Howard of the BR when he gave evidence um and let's let's cover that that's at page 51 of your report at paragraphs 374 and
02:19:53 following yes y now um your opinion on that desktop and again I'm summarizing but is this correct was that it was inadequate at least in showing its workings and calcul calculations um was
02:20:06 workings and calcul calculations um was in part unsubstantiated by reference to technically credible supporting evidence that's right yes and it didn't conform to the principles in the pfpf guide no
02:20:17 to the principles in the pfpf guide no um the the next one is at 440 page 61 I'm get summarizing back to you the your opinion and its effect page 61 paragraph 440 this is the second one this is H&H
02:20:28 440 this is the second one this is H&H done on the 26 21st of April 2016 by H&H fire prepared by fire quotes fire engineer unquote Francis Lee reviewed by quote senior engineer Jay
02:20:39 reviewed by quote senior engineer Jay endan and approved by quotes director Glenn Horton Glenn Horton uh now I think your opinion on that was that it was inadequate and lacked basic competence not least cuz
02:20:50 lacked basic competence not least cuz it's signed off the use of RAB Bond pacm as cladding materials which quotes will not propagate fire close quotes uh that's right I mean this this one I thought was particularly uh what's the
02:21:01 thought was particularly uh what's the word upsetting if you like upsetting because it offended your scientific principles or in some other way U yes because it offended my scientific principles because it
02:21:12 scientific principles because it highlighted um some of the misconceptions that this inquir has been dealing with because it said that um ACM PE was was fine um without apparently
02:21:25 PE was was fine um without apparently recognizing any fire hazards whatsoever associated with acmp it's just a it's just a I mean I don't I don't use the word incompetent lightly but it's a from
02:21:36 word incompetent lightly but it's a from my perspective it's an utterly incompetent report now go back to paragraph 440 just look at it on the screen you've put the words fire engineering quotation marks why was
02:21:48 that um I mean while we're here should point out I did notice the other night there is an error in 441 the following small paragraph where I say it's unclear which is relevant to the question you've just asked me uh fire engineer uh and
02:22:00 just asked me uh fire engineer uh and Glenn Horton is listed as senior engineer uh that's wrong Glenn Horton is listed as director he's not listed as senior engineer so probably just highlight that for you um uh why have I put fire engineering quotations uh
02:22:11 put fire engineering quotations uh essentially because there is no such thing uh if you like as a fire engineer there there is no legal protection to the title fire engineer uh we could there's we we could
02:22:26 engineer uh we could there's we we could we could talk about um uh professionals who uh are ceng under the engineering counil via the
02:22:37 under the engineering counil via the institution of fire Engineers is that a fire engineer um I don't know if um uh Francis Lee is ceng via
02:22:48 um uh Francis Lee is ceng via engineering Council and the institution of fire Engineers um but but the reason it's in quotes is that anyone's entitled to call themselves a fire engineer in the United Kingdom and that as I've said before and we'll say again is a very
02:23:00 before and we'll say again is a very significant problem in my
02:23:07 view and then I think you also point out that one of the errors beving this report was the the assertion that Euro Class B is equivalent to class not that's right
02:23:19 equivalent to class not that's right yeah
02:23:20 yeah uh now um I think you also examined four uh assessments by xover done between May 2015 and may 2016 and we can find that on page 68 and following if we go to
02:23:31 on page 68 and following if we go to that please paragraphs
02:23:37 493 uh uh Under The Heading 6.3 xover Warrington far desktop assessment reports uh and you set them out uh what was your overall opinion about the
02:23:48 was your overall opinion about the quality of these assessments uh pretty
02:23:53 uh pretty inadequate in my view by which I mean not not evidence-based uh uh you know the the depth of information was insufficient
02:24:05 depth of information was insufficient for me
02:24:06 for me to
02:24:08 to understand uh the opinions that have been given or to interrogate them for myself um the extent to which uh I was provided information that would allow me
02:24:19 provided information that would allow me to understand materials and products from which the systems either tested or proposed uh were built up was was inadequate um few if any drawings provided to help
02:24:32 um few if any drawings provided to help me understand how the systems went together you know very what I would consider to be just absolutely basic information that one would expect in these reports was not there and and and as a consequence you're left or I was
02:24:45 as a consequence you're left or I was left in any case with um with view that you know what these reports basically say is here's a here's a someone wants to do
02:24:57 is here's a here's a someone wants to do something on a building um I've looked at some other tests that we've done on systems that aren't the same as that system and I feel that everything is going to be fine on the basis of the criticisms that
02:25:09 fine on the basis of the criticisms that you've made both in the report just for reference purposes at paragraph 525 page 72 and on what you've just told us Professor are you able to form any opinion of the competence experience and
02:25:21 opinion of the competence experience and qualifications of those who prepared
02:25:25 them uh well I don't know the background of those individuals um so I don't know I don't know what their uh sort of demonstrable credentials or competence or experience would have been I could
02:25:37 or experience would have been I could only base it on what I saw in front of me on the basis of the reports and I would say that that that either the people who were doing those reports lacked the requisite competence to do a proper job um or
02:25:50 competence to do a proper job um or chose not to do a proper
02:25:54 job well perhaps we're just having an off
02:25:57 off day I don't think you're allowed to have an off day when you're dealing with matters like this that's I mean that's why we have checks and reviews by other competent professionals within the system that's
02:26:09 professionals within the system that's why this is never left up to one person which is particularly important comment with respect to the exova Warrington fire desktop
02:26:18 reports and is it your opinion that the questions of competence and quality are crucial because the entire system depends on a series of subjective assessments to be made by the relevant
02:26:31 assessments to be made by the relevant person uh that our ENT our entire system of building regulations as I've said in this report is predicated on the assumption that we can rely on the competence and professionalism of the
02:26:42 competence and professionalism of the individuals who are acting within it now just picking up the point um about checks and balances and other competent professionals within the system can we go please to page 39 of
02:26:54 system can we go please to page 39 of your report which is back a a few pages back 30 pages page 39 at paragraph 290 the foot of the screen you say nor am I aware that prior of the
02:27:06 say nor am I aware that prior of the Grandfield Tower fire any legal or regulatory requirements existed to compel anyone to demonstrate any particular level of knowledge skills or experience in order to offer their services in performing desktop
02:27:17 services in performing desktop assessments no serious attempt appears to have been made to Define to independently assess or to provide any form of rigorous independent oversight of the competence of practitioners so as to ensure that across the industry such
02:27:29 to ensure that across the industry such individuals could credibly be deemed suitably competent to produce such assessments now as you note in other sections of your report practitioners are required to decide for themselves
02:27:40 are required to decide for themselves whether or not they are competent to undertake those assessments do you consider that to be a satisfactory situation no so in any revised
02:27:51 situation no so in any revised system would it be your opinion that there needs to be built into it a solid robust and rigorous system of peer review independent peer review
02:28:03 review um yes yes uh but I but I would caveat that by saying when we insist on uh peerreview there's there's two aspects
02:28:15 peerreview there's there's two aspects to peer review one is peer review of the project so you could say yes I'm going to demand peer review uh of this particular desktop assessment report so I'm going to have
02:28:26 assessment report so I'm going to have two sets of eyes if you like look at it uh and
02:28:29 uh and agree so we can assess the projects or the reports but we can also assess the people um and I think that is perhaps even more
02:28:40 important so there there there should be some assessment of the professionals themselves and there should be some ongoing review and some requirement in order to essentially have a license to
02:28:51 order to essentially have a license to practice in this space in many spaces now um if we go please to um paragraphs uh 72 to 81 of this
02:29:02 uh 72 to 81 of this report uh which you'll find just go back to it um
02:29:10 please uh thank you um you deal under paragraph 2.1.2 with pass
02:29:18 9980 uh
02:29:23 which you then set out at that paragraph and in paragraph 73 and then at paragraph 76 you say pass 9980 neither clearly defines what is
02:29:34 9980 neither clearly defines what is meant by competence nor provides much assistance in terms of how this competence should be assessed verified maintained controlled or monitored across the sector it appears to leave these questions up to clading fire risk
02:29:45 these questions up to clading fire risk assessors to Simply satisfy themselves in italics themselves that they have quotes adequate and relevant competence close quotes and that they quotes have
02:29:56 close quotes and that they quotes have sufficient knowledge skills and experience in relation to fire safety of external walls to be able to complete an assessment at the level required close quotes and you go on to say and make other CR you make other criticisms at
02:30:08 other CR you make other criticisms at paragraph 78 7778 and 7 79 and at 79 you say as a result my impression is that pass 9980 whilst appearing well intentioned does little to raise the bar
02:30:20 intentioned does little to raise the bar of the clading fire risk assessment community and instead offers a formulaic methodology for undertaking such assessments which I believe ought to be obvious to anyone who genuinely has the
02:30:32 obvious to anyone who genuinely has the requisite competencies in Fire Safety Science and Engineering General fire risk assessment and clading fire risk
02:30:41 assessment and then you go on to say at 80 I also believe that it should be recognized that the existence of pass 9980 could perhaps counterintuitively generate in italics generate a risk that
02:30:53 generate in italics generate a risk that fire risk assessors who lack the requisite competence might be given a full sense of confidence and might therefore use P 9980 to undertake cladding fire risk assessments that they or their professional Indemnity insurers
02:31:05 or their professional Indemnity insurers might otherwise
02:31:08 refuse now in in Paris 79 you you use the expression of formulaic methodology what do you mean by that I mean p 9980 says you follow these steps
02:31:21 mean p 9980 says you follow these steps steps if you want to you know if you want to do a risk assessment you follow these steps and what's wrong with that
02:31:28 that uh uh following steps does not help someone who lacks the the the fundamental understanding uh or or has
02:31:41 fundamental understanding uh or or has experience of dealing with these systems um it doesn't give them the knowledge they need to make the subjective judgment that need to be made all it tells you is that you you you you do
02:31:53 tells you is that you you you you do this and then you decide using your subjective judgment and your self assessed competence that you can say yes this is fine or no this isn't fine but it doesn't help that
02:32:04 isn't fine but it doesn't help that person to understand what is or is not fine it just kind of walks them along the path um and uh it doesn't it doesn't
02:32:15 the path um and uh it doesn't it doesn't generate the knowledge or experience that we talked about a few minutes ago that I've said was so sorely lacking what it what it what it does um is it creates the
02:32:26 creates the impression of substance of knowledge and experience uh without actually if you read the document um it you know it sort of says
02:32:40 document um it you know it sort of says the goal of this document is to um is to is to increase the competence of of people doing these assessments and I don't think it does that I think think what it does is it helps people to feel
02:32:52 what it does is it helps people to feel that they have The Confident competence when in reality they don't and that's why I think it's dangerous you know I think I've said I've said before I don't know it was in the context of the inquiry that one you know one of the one of the problems with setting up
02:33:06 of the problems with setting up formulaic
02:33:07 formulaic rules uh one of the dangers of rules is that people will follow them uh and they might follow them in situations where they shouldn't follow them and what's important is not to have rules that people can follow what's
02:33:19 rules that people can follow what's important is that people understand the rules and and past 999998 I don't think does much to help people understand why they're doing what they're doing it just tells them that they'll be fine if they
02:33:31 tells them that they'll be fine if they do
02:33:34 it Professor I come to the end of my prepared questions uh and so I'm going to ask the chairman to take the usual short break yes while we see whether any other questions I have for you which
02:33:45 other questions I have for you which I've missed or whether there are others who wish me to ask further questions of you sure I should think 10 minutes ought to be enough shouldn't it uh yes I think so well if you need more time you can
02:33:56 so well if you need more time you can obviously let us know yes thank you well Professor Bisby as you know we we have a break at this stage for reasons you're well aware of so we'll stop now we'll return Please at quarter to 1 and then we'll see whether there are any more
02:34:07 we'll see whether there are any more questions to be put to you sure thank you right thank you very
02:34:18 much thank you Mr milet we'll say course to one if you need more time you can let the Usher come and tell us thank
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02:57:39 and would you ask Professor Bisby to come back in please
02:57:49 [Music]
02:57:53 all right Professor we'll see if there are any more questions sure yes Mr chairman first of all thank you for staying out for a little bit longer there are two questions first of all Professor uh you told us earlier this morning the raw transcript it's page 32
02:58:05 morning the raw transcript it's page 32 at line lines 21 to 25 that uh the line burner you used was 30 to 40 kilowatt but in an SBI you've got a 300 kilowatt burner a bigger Source left for longer
02:58:18 burner a bigger Source left for longer is it right that in an SBI test it's it's a 300 kilowatt I'd have to check certainly more than our burner but I'd have to check the standard to know for sure right I I would you accept uh that
02:58:31 sure right I I would you accept uh that in fact it delivers a nominal heat release rate of 30 kilowatt oh interesting okay uh which would translate to a maximum heat flux input on the samp on samples of less than 40 kilowatt per square
02:58:44 kilowatt per square meter I'm surprised by that but if that's the truth then we have to accept it yes now um second question um I asked you about competence and particularly competence of people to do desktops
02:58:56 competence of people to do desktops under uh under um what one might call the alternative within paragraph 12.5 uh namely meeting the performance requirements uh under BR 135 uh would a
02:59:10 requirements uh under BR 135 uh would a similar uh pool of competence or level of competence be required to apply what I might call the linear route to compliance through 12.6 to
02:59:31 12.9 I would probably argue it's interesting question I would probably argue that the the linear
02:59:42 probably argue that the the linear route it's hard to say in general terms but the the linear route and the the tests upon which the linear route is based are these unrepresentative tests and as model tests pardon me model tests
02:59:55 and as model tests pardon me model tests sorry model tests and as I've as I've as I've discussed uh as we discussed uh on Monday the kind of the the burden of uh
03:00:06 Monday the kind of the the burden of uh of uh consideration increases as you go from unrepresentative tests to model tests through to uh the system tests the technological proof tests so I
03:00:18 technological proof tests so I I think I would probably argue but I I don't know how you would quantify this I would probably argue you need slightly you would need slightly less detailed understanding to apply the results of the linear route than you
03:00:30 results of the linear route than you would for uh a br 135 assessment but at at the end of the day the people who are making these decisions they need to um have some understanding
03:00:44 to um have some understanding of what what the tests are assessing what the outputs mean and therefore how to apply those to a real building
03:00:54 building uh I don't really see any significant difference in terms of the kinds of knowledge and experience we would expect people to have for those two scenarios if I'm
03:01:03 if I'm honest no I think I think you could probably be slightly more confident uh although I can't quantify that in any sensible way that um a clouding system
03:01:14 sensible way that um a clouding system that Accords with the requirements of the so-called linear route ER is something you could have a bit more confidence with without without thinking about it at all but of course I would expect you to think about
03:01:25 would expect you to think about it and and would that go for taking a class not panel to be used in a highrise building above 18 MERS but still having to ask the question how will it perform
03:01:37 to ask the question how will it perform mechanically in the event of a fire how will it interact with the other elements of the external wall buildup what is the use of the building absolutely yes yeah thank you very much well I've come to
03:01:48 thank you very much well I've come to the end of my prepared questions uh and the end of your evidence uh as a whole um I just wish to express the inquiries gratitude to you and my own gratitude to
03:01:59 gratitude to you and my own gratitude to you for answering our questions thank you very much Professor thank you and Professor Bisby before you go it's right that I should thank you personally and on behalf of uh my colleagues on the panel for all the work you've done you
03:02:11 panel for all the work you've done you have in fact done an enormous amount of work for the inquiry we've read your reports and they are Illuminating and if I may say so very interesting and uh We've benefited enormously from hearing
03:02:22 We've benefited enormously from hearing your evidence so thank you very much indeed we're greatly indebted to you you're very welcome and and I mean I should say thank you for um for the patience uh and tolerance of of allowing me and my team to do the things that we
03:02:34 me and my team to do the things that we that we said we needed to do in order to try to answer the questions we were asked so thank you very grateful I should also Express uh the inquiry's thanks not only to you Professor but to your entire Team without his work I I know you would have perhaps had greater
03:02:47 know you would have perhaps had greater difficulty uh to put it mildly yes thank you thank you good thank you very much well then that's the end of the questions you're now free to go thank you
03:03:02 you thank you very much Mr mlit well that's it for the morning we have another witness this afternoon Professor Terrero is coming back then Professor Terrero will come to assist you at uh this afternoon at a time to be fixed uh
03:03:14 this afternoon at a time to be fixed uh and um he will be assisted uh through his evidence by Miss gra Queen's Council thank you very much well we've slightly overrun this morning I think we'll say five fast two thank you thank you very
03:03:25 five fast two thank you thank you very much 5 F two