Fire Engineer Expert Presentation - Tuesday 10th November 2020 (2/2)

Full transcript

00:00:13 would you ask dr lane to come back in please

00:00:22 [Music]

00:00:35 so chairman before dr lane begins right i'm sorry right dr now before you start ms granger's been asked to repeat the warning so that people who join us part

00:00:46 warning so that people who join us part way through yeah aren't taken by surprise yes thank you mr chairman so um i need to give a trigger warning about some of the content of this presentation included in this presentation are some

00:00:57 included in this presentation are some images

00:00:58 images and videos of friar scenarios and also included some images of grenfell tower on the night and when on fire including some images taken from inside the tower after the fire so

00:01:10 inside the tower after the fire so anyone who doesn't want to see those kind of images um shouldn't watch this presentation um okay thank you very much thank you very much um

00:01:22 much um yes stop playing well i think we're ready to continue okay if you are thank you

00:01:26 you yes okay so for the next hour i'm going to cover two final subjects so uh first the european

00:01:37 so uh first the european reaction to fire test classification system

00:01:40 system so i've explained the four european reaction to fire tests so now i need to explain the classification system which is published to use with them i will explain how the

00:01:53 to use with them i will explain how the classification system considers all that data produced from those tests and explains how to use the data to classify

00:02:01 classify construction products

00:02:04 the overarching classification standard for european reaction to fire testing is presented in bsen 13501-1

00:02:15 is presented in bsen 13501-1 the fire classification of construction products and building elements using test data from reaction to fire tests the scope of the standard states this

00:02:26 the scope of the standard states this european standard provides the reaction to fire classification procedure for all construction products including products incorporated within building elements

00:02:38 elements products are considered in relation to their end-use application this document applies to three categories which are treated separately in this european standard

00:02:50 european standard i will focus on construction products only today

00:02:56 i have exerted some key definitions set out in the standard for substrate standard substrate and end use application it's important

00:03:07 and end use application it's important to understand those definitions substrate is a product which is used immediately beneath beneath the product about which information is required

00:03:18 information is required the classification standard also communicates something called a standard substrate

00:03:25 substrate a product which is representative of the substrate used in end-use applications and the end use application is also given a definition the real application of a product

00:03:37 the real application of a product in relation to all aspects that influence the behavior of that product under different fire situations

00:03:49 first in the classification standard it provides a table one all the different european classes these are in letter form unlike the

00:04:00 these are in letter form unlike the national classes which are typically numeric in form for each class this table states a classification can only be obtained

00:04:11 only be obtained by undertaking the tests or the extended application process required for that particular product the table lists the specific tests relevant to the

00:04:23 the specific tests relevant to the particular european class as presented on the slide now it provides a narrative explanation of the requirements in the main body of the text in the

00:04:34 in the main body of the text in the standard that follows table one contains seven material classifications possible ranging from the highest european class a1

00:04:45 a1 down to the very lowest european class f it lists the combination of specific tests required and it lists the specific classification classification criteria

00:04:57 classification criteria required within each test and you will start to see where all this extensive analysis to form parameters is starting to become relevant

00:05:10 is starting to become relevant i will now go through each of the european classes starting with the highest performance a1 the limits i am about to describe our firm are far homogenous materials and

00:05:22 firm are far homogenous materials and substantial components of non-homogeneous products note that for composite materials each layer

00:05:29 layer must be tested composite materials use the same tests however the relevant limits

00:05:37 limits are a little more complicated depending on where each material sits relative to each other and the thickness of the layers evidence of an a2 cord acm panel has

00:05:50 evidence of an a2 cord acm panel has been submitted to this inquiry and this was considered as a composite and hence the limit for composites was applied and i just wanted to make that point clear

00:06:01 that point clear no relevant test evidence has been submitted to the inquiry for an insulation material achieving a1 or a2 so i'm actually not clear

00:06:10 clear whether it would be treated as a homogenous material or whether the foil facing would result in it being a class considered a composite material

00:06:23 [Applause] class a1 requires test data from two reaction to fire tests the gross heat of combustion measured in the bomb calorimeter

00:06:34 the bomb calorimeter and the non-combustibility furnace test on the screen we have shown the requirements and a reminder of the test apparatus to be classified as a1 the material must

00:06:48 to be classified as a1 the material must also

00:06:48 also be tested in the bsen iso 1182 furnace and cause a rise in furnace temperature no greater than 30 degrees celsius the

00:06:59 no greater than 30 degrees celsius the specimen should not degrade by more than 50

00:07:02 50 during the test and there should be no sustained flaming observed on the specimen

00:07:08 specimen only where a material meets all these criteria

00:07:11 criteria cannot be classified as a1

00:07:18 there are two combinations of tests that can be used to classify a material as class a2 remember that a class a2 material would be considered a material of

00:07:30 would be considered a material of limited combustibility under approved document b and so would apply to an insulation material in either company combination the single burning item test is required

00:07:42 burning item test is required and that's the test with the corner specimen shown in the bottom photograph the material must achieve a fire index growth rate figure of less than 120 watts per second

00:07:54 figure of less than 120 watts per second in the single burning item test the flame front must not extend to the edge of the long wing and the total heat release in the first 600 seconds

00:08:05 seconds after the primary burner is ignited must not exceed 7.5 megajoules in addition to the single burning item test the material should be tested in the bom

00:08:16 the material should be tested in the bom calorimeter or the electric furnace as part of the non-combustibility test for bsen iso 1716 the requirement for class a2 is that the

00:08:29 the requirement for class a2 is that the heat of combustion does not exceed 3 megajoules per kilogram for the non-combustibility test the furnace thermocouple temperature must not rise by more than 50 degrees c

00:08:41 must not rise by more than 50 degrees c and the material specimen must not degrade by more than 50 percent and finally the specimen must not flame more than 20 seconds it is at the discretion of the sponsor

00:08:52 it is at the discretion of the sponsor whether they test in accordance with combination 1 or combination 2 to demonstrate class a2 both are acceptable means under the european classification system

00:09:09 european classification system the next european classification is class b

00:09:13 class b from european class b downwards there is a different set of test combinations required

00:09:19 required the non-combustibility test and the bomb calorimeter are no longer used and the remaining classifications rely on the single burning item test and the

00:09:30 on the single burning item test and the single flame source tests only the next five slides highlights the requirements to classify a material as class b c d e and down to the lowest

00:09:42 d e and down to the lowest classification possible f as you'll see the testing remains much the same

00:09:49 the same but the requirements when analyzing the data recorded in the test become less onerous as the classifications move down to f a class b material must achieve a fire

00:10:01 a class b material must achieve a fire growth index a fire growth rate of less than 120 watts per second in the single burning item test the flame front must not extend to the edge of the long wing

00:10:13 of the long wing and the total heat release in the first 600 seconds must not exceed 7.5 megajoules in the single flame source test a class b material must have had a 30

00:10:24 a class b material must have had a 30 second exposure and the flame must not have spread to the reference line at the end of the test

00:10:30 test which is 60 seconds material must satisfy the criteria for both the single burning item test and the single flame source test to be classified as class b

00:10:42 as we move down to a class c material you'll notice the testing combination required doesn't change

00:10:49 change but as i've highlighted in blue the fire index growth rate may now go up to 250 watts per second and the total heat release rate in the first 600

00:11:00 heat release rate in the first 600 seconds has increased to 15 megajoules and this is class c for class d the fire index growth rate figure increases to 750 watts per second

00:11:14 figure increases to 750 watts per second note that the lateral flame spread and total heat total heat release rate are no longer criteria

00:11:22 criteria in the classification standard there is no change in criteria from the single flame source test

00:11:32 the next important change occurs at class e

00:11:35 class e now only a single test the single flame source test is required and the exposure time has decreased to 15 seconds with the five second observation period

00:11:48 with the five second observation period class f is applied when a product has no performance criteria it is it also applies if a product fails to obtain class e when tested to the single flame source

00:12:00 when tested to the single flame source test

00:12:04 i have summarized the classifications and the tests required to obtain them here for the seven european classes for reference

00:12:16 now i need to talk again about little s and little d

00:12:22 the image on the screen now is taken from section 14 from the classification standard it lists

00:12:29 lists all the possible combinations of european classification as i have just presented

00:12:35 presented and it shows the sliding scale from a1 down to f but each of these is further subdivided based on the volume of smoke production

00:12:47 based on the volume of smoke production and flaming droplets production

00:12:55 classification s1 s2 s3 for smoke production are deduced from the measuring data obtained in the single burning item test

00:13:06 in the single burning item test specifically from the data that produces the smoke growth rate or smogra classifications d0 d1 and d2 for flaming droplets and particles are

00:13:19 for flaming droplets and particles are deduced from observations of flaming droplets and particles in the sink in the single flame source test and

00:13:25 test and the single burning item tests i have set out the limits for all the s's and d's i'm not going to go through them again now but it is important to

00:13:37 them again now but it is important to understand that the approved document b cited s3 and d2 only in 2013 and therefore set no limit for smoke production

00:13:48 production or flaming droplets and particles

00:13:56 a final note regarding classification to the european standards

00:14:05 the classification standard states the field of application of the classification is identical to the field of application resulting from the tests or from or from the extended application

00:14:16 or from or from the extended application process

00:14:18 process if different end-use applications are envisaged for a particular product this may result in different classifications in considering substrates and backings

00:14:29 in considering substrates and backings which can be applied in practice the classification specifies standard substrates for use in tests and also gives rules

00:14:40 in tests and also gives rules for the field of application of test results obtaining obtained using those standard substrates the use of standard substrates is not mandatory

00:14:51 mandatory instead the product may also be tested in its end use conditions with the substrate

00:14:58 substrate representative of the end use when such a representative substrate is used

00:15:05 used the test result is limited only to that same

00:15:08 same substrate in its end use application the applicability of test results obtained for products attached to a substrate is limited to the method

00:15:20 to a substrate is limited to the method of attachment used in the test

00:15:24 an extended field of application is the outcome of a process involving the application of defined rules

00:15:33 rules that predict a test result but based on one or more test results to the same standard

00:15:44 for any product or material a fire test report

00:15:48 report and a classification report is required these photos are taken from the french test reports for renault bonds it is not possible to understand

00:15:59 understand the substrate or the full details of the fixing for the system being tested by this visual means only

00:16:10 on screen now is the specific field of application stated in that particular assessment report

00:16:17 report for the archonic renault bond 55 pe riveted system it's important to read the specific nature of the field of application

00:16:28 of the field of application it refers to a system riveted on any metallic

00:16:32 metallic substructure and it makes clear the substrate

00:16:36 substrate must be to an a1 or a2 standard with a particular density greater than 700 kilograms per meters cubed it also specifies a minimum air gap

00:16:48 it also specifies a minimum air gap of 50 millimeters

00:16:58 the european classes are also referred to from approved document b back to table a6 but this time in the european class

00:17:10 european class part of the table there there are two definitions of non-combustible provided as you can see highlighted on the screen the first blue box at a relies on

00:17:22 the first blue box at a relies on testing and classification as i've just described

00:17:26 described the second option in the lower blue box is by means of specific materials deemed to satisfy the performance back up at paragraph a it states there

00:17:38 back up at paragraph a it states there that non-combustible materials are any material classified as class a1 to the classification standard

00:17:52 the second fire definition provided in approved document b is in table a7 this is a key definition regarding the insulation products

00:18:03 insulation products you can see in paragraph a that any material defined as non-combustible will also satisfy the european class for limited combustibility too

00:18:15 combustibility too secondly as marked at point b a material of limited combustibility is defined as a material or product classified as class a2 s3 d2

00:18:26 as class a2 s3 d2 or better this relies on the test evidence from the two combinations of testing i explained earlier

00:18:37 however a material of limited combustibility which has a european class designation is also referenced for another part of the external wall so back again to table a7

00:18:50 so back again to table a7 up at row 6 marked here class 0 materials meeting the provisions in appendix a paragraph 13a state

00:19:01 paragraph 13a state if a material or the surface of a composite product is one of two performances again the first being composed throughout of materials of limited combustibility

00:19:13 limited combustibility and that means class a2 s3 d2 or better as i have just described it's essential to be aware this is not in the insulation row

00:19:25 this is not in the insulation row in table a7

00:19:29 but i want to discuss diagram 40 when considering the european classes

00:19:37 taking grenfell tower as the building example

00:19:40 example the external surface classification was class b

00:19:43 class b s3 d2 or better for the building because it had a dimension over 18 meters and it was 000 millimeters more from the relevant boundary to adjacent

00:19:54 from the relevant boundary to adjacent buildings

00:19:55 buildings and this applied to the parts of the building over 18 meters so looking at the yellow box highlighted on the building there on the screen and the reference to class b in the blue

00:20:06 and the reference to class b in the blue box marked on the screen this meant the composite product used for the external surface needed to have been tested as a minimum to the single burning item test

00:20:17 to the single burning item test and a single flame source test exactly are set out on the right hand side of diagram 40.

00:20:26 but if you look at the national and european classes together for the external surface of the building this means the surface must either be class

00:20:35 class naught or class b s3d2 but the issue is by definition using european classifications class naught can only be achieved via

00:20:47 class naught can only be achieved via class 13

00:20:48 class 13 clause 13 a and so must be class a2 s3 d2 or better this is a higher performance standard than set out in diagram 40 which refers

00:20:59 than set out in diagram 40 which refers to class b there is therefore a disparity

00:21:03 disparity between the national class designation and the european class designation

00:21:14 finally when i was explaining the test procedures for the european tests i referred regularly to various calculations required from the test data i now want to show briefly their

00:21:26 i now want to show briefly their relevance to the european classes

00:21:32 first for insulation required to achieve class a2

00:21:35 class a2 s3 d2 or better table 1 states data is required from two test standards and the limits from the data recorded in the test is also made

00:21:47 the test is also made clear in the classification standard and those limits are shown on the screen it can be also a2 can be obtained using these two test standards

00:21:58 test standards and again the limits when using this combination are clearly shown on the screen

00:22:07 the requirement for the external surface was to achieve class b d2 and table 1 of the classification standard

00:22:16 standard again sets out clearly the criteria for the classification standard using the data and calculations from those tests so for

00:22:27 those tests so for all the possible combinations of european classification and the sliding scale down from a1 to f the test data and the calculations are clearly set out in the classification

00:22:39 clearly set out in the classification standard

00:22:40 standard and each one has limits set for the relevant european class

00:22:50 the inquiry has made me aware of a study on equivalency regarding the national and european classes

00:22:59 in 2000 xover warrington fire research issued a report titled radar 2 project correlation of uk reaction to fire classes

00:23:10 fire classes for building products with euro classes and guidance on revision of approved document b a total of 64 products were tested

00:23:21 a total of 64 products were tested to the national and european reaction to fire tests across seven so-called sectors of wood mineral wool paints

00:23:32 of wood mineral wool paints cellular plastics wall coverings boards and sheets and plastics

00:23:41 the introduction to part two of the report states the objective of this part to work is to consider how the test results and classifications obtained in the part one report may be compared

00:23:54 in the part one report may be compared so that classification transpositions may be identified and if satisfactory correlations can be established to propose to detr how a supplementary

00:24:06 to propose to detr how a supplementary guidance document for approved document b

00:24:08 b may be prepared

00:24:13 when comparing the equivalence of class naught and the european classifications 35 class north products were compared four wood based three mineral wool

00:24:25 four wood based three mineral wool insulation products six types of paint seven types of cellular plastic insulation product six different wall coverings six board and sheet products

00:24:36 and sheet products and three plastic based products

00:24:41 i do not understand the purpose of testing three mineral wool insulation products

00:24:45 products nor the cellular plastic insulation for class naught as this was not the relevant performance requirement as i've stated earlier the only cladding panel tested was a an

00:24:57 the only cladding panel tested was a an fr

00:24:58 fr high pressure decorative laminate panel on screen now is table two taken from part two

00:25:06 part two of the report that shows products that were tested and achieved class naught and their subsequent european classification

00:25:16 i've taken these results and i've shown them on the screen now it can be seen that the majority of the class naught samples achieved class b however one of the samples was as low as class e

00:25:29 samples was as low as class e this was a wood fiber meat board the class c product was an aluminium faced phenolic foam insulation and the class d product was an aluminium phase pir

00:25:41 an aluminium phase pir insulation the only panel tested was an fr hpl

00:25:46 fr hpl panel and it achieved class b

00:25:52 on screen now i have exerted the conclusions of part two of the radar report with regards to pir and phenolic foam insulation with these products it was observed that

00:26:05 with these products it was observed that in the single burning item test the aluminium foil facing was penetrated such that the underlying foam was then available

00:26:13 available to contribute to the rate of heat release calculations whereas in the bs 476 part 6 the heat release found in the test was not sufficient

00:26:24 not sufficient to displace sorry excuse me displace the classification away from the uk class naught clearly the introduction of a simple

00:26:35 clearly the introduction of a simple replacement of the uk class note by eu euro class b requirement in any regulatory procedure would discriminate against products listed on the slide against the

00:26:47 products listed on the slide against the practical experience of their acceptability in the uk market for class note applications i find the radar reports are very detailed and require

00:26:58 detailed and require careful study but i found this particular paragraph particularly striking

00:27:03 striking any reference to class naught being equivalent to euro class a2 would severely restrict the market choice in terms of materials for specifiers and clients

00:27:14 specifiers and clients this applies to virtually all organic containing materials in germany and france the authorities have a single classification thus euro class b could be a

00:27:25 thus euro class b could be a cross-border compromise which is supported by the high product density obtained at the class naught euro class b transposition point

00:27:38 finally the european classes were referred to regarding the grantful tower primary refurbishment external wall products only one product installed on

00:27:50 products only one product installed on grenfell tower was presented as relying on the european classification system and this was the renault bonds 55 pe panel celotex did not test their

00:28:01 55 pe panel celotex did not test their insulation to the european tests until after the grenfell terror fire on screen now is the bba agreement certificate for the archonic renault panels i have

00:28:12 for the archonic renault panels i have highlighted how the bba represented the standard sample it relied on

00:28:17 relied on with the classification of bs2 d0 no field of application information was provided

00:28:26 provided this concludes my presentation on the european classification and reaction to fire testing methods thank you

00:28:57 okay the last section

00:29:02 this is the final section of my presentation and it focuses on the subject of cladding systems and not individual products as i have dealt with so far

00:29:13 products as i have dealt with so far i explained the fire tests for clouding systems referred to within the approved document b and these are called british standard 8414

00:29:21 8414 parts one and two i explain the performance criteria given in the bre report br 135 on the subject of fire performance of external thermal insulation

00:29:33 external thermal insulation for walls of multi-story buildings also referred to within approved document b this explains the performance criteria to assess the test data from the 8414 tests

00:29:47 as a reminder paragraph 12.5 of adb states the external envelope of a building should not provide a medium for fire spread if it is likely to be a risk to health

00:29:59 if it is likely to be a risk to health or safety

00:30:00 or safety the use of combustible materials in the cladding system and extensive cavities may present such a risk in tall buildings external walls should either meet the guidance given in paragraphs 12.6 to

00:30:12 guidance given in paragraphs 12.6 to 12.9

00:30:14 12.9 or meet the performance criteria given in the bre report for clouding systems using full-scale data from british standard 8414 parts one and two

00:30:27 so the full-scale data adb refers to is generated using the 8414 test and it is then evaluated using the performance criteria and classification

00:30:38 performance criteria and classification method described in the bre document

00:30:44 first however i want to explain the derivation of these tests and their performance criteria these methods are founded on principles aired since the nineteen eighties

00:30:55 since the nineteen eighties in 1988 regards getall undertook experiments at the bre cardington laboratory due to the rise in what was then the new

00:31:06 due to the rise in what was then the new technique

00:31:06 technique of the application of thermal insulation on the outside face of buildings ragawski stated the use of appropriately designed systems

00:31:17 designed systems particularly on the walls of high-rise buildings

00:31:20 buildings provides an attractive method of energy conservation he stated the need for improved thermal insulation of buildings had led to the introduction of a range

00:31:31 had led to the introduction of a range of systems originally designed for external application to solid masonry walls but noted they were now being extended in application by means of installation on

00:31:43 application by means of installation on the outside of multi-story developments done so as not to disturb occupants during the installation

00:31:52 raganski as part of the introduction to the report identified that control over the external surface of walls of buildings particularly those of multi-storey flats was controlled by reference to bs

00:32:04 was controlled by reference to bs 476 part 6 and part 7. however he advised that this only provided information on the surface fire behavior

00:32:14 behavior going on to state that the overall fire performance of ventilated cladding systems

00:32:19 systems could only be investigated under actual fire conditions on a full-scale building facade to identify the design principles

00:32:30 to identify the design principles affecting the safety of occupants and the probable extent of fire spread rugowski of the bre conducted large-scale tests in a four-story experimental building

00:32:42 experimental building that was 9.2 meters high and 3.7 meters square

00:32:46 square in plan

00:32:47 in plan [Music]

00:32:50 [Music] on screen now are three of the key conclusions made by rogowski as a result of his large-scale experimental work to reduce the risk of vertical fire spread in existing

00:33:01 spread in existing and proposed external insulation systems the following recommendations based on this test program are proposed to the department of the environment

00:33:12 environment proposed systems incorporating combustible insulin which sheeted over cladding should be designed to incorporate fire barriers in the ventilated cavity every two stories

00:33:24 stories surface protection applied directly to all combustible insulins must be carefully designed and installed around windows and other openings timber clouding should continue to be used

00:33:36 continue to be used only in low low-rise developments to avoid extensive self-propagating flame spread over the surface the bre were at the time an executive agency of the department of the

00:33:47 agency of the department of the environment

00:33:51 three years later in 1991 a fire occurred in an 11-story tower block called nowsley heights in merseyside the fire occurred when rubbish was set alight outside the

00:34:02 rubbish was set alight outside the building

00:34:03 building the fire spread from the ground floor up the full height of the external wall of the building and this triggered further work at the bre undertaken by dr raymond connolly in 1994.

00:34:15 1994. in relation to noseley heights fire dr connolly states in his 1994 report which was titled investigation of the behavior of external cladding systems

00:34:26 behavior of external cladding systems and fire

00:34:27 and fire a report on 10 full-scale fire tests that the overcladding system involved achieved a class naught rating and the insulation was non-combustible

00:34:39 and the insulation was non-combustible he also stated that one of the reasons for the rapid spread of the fire was an unusual construction detail which effectively created a flu that traveled up through the height of

00:34:50 that traveled up through the height of the building

00:34:53 dr connolly's 1994 report goes on to detail out an an experimental investigation into the performance of external clouding systems on exposure to fire

00:35:06 on exposure to fire the objective of this particular investigation was to assess the effectiveness of installation of fire barriers

00:35:13 barriers in reducing the fire hazard non-combustible insulation was used in each test

00:35:19 each test and two types of external overclouding that achieved class naught relying on british standard 476 part 6 and 7 tests were installed the test rig was of a

00:35:30 were installed the test rig was of a similar scale to rigalsky at all the overall conclusions formed by connolly included the need to install fire barriers in external clouding systems with cavities to reduce the

00:35:43 systems with cavities to reduce the potential fire spread that fire protection solely around the windows was inadequate that reduction of the width of a cavity reduced the surface spread of flame

00:35:54 reduced the surface spread of flame over the cladding material of particularly relevance was he concluded that small-scale reaction to fire properties of the cladding materials

00:36:04 materials did not reflect the fire hazard associated with the full-scale cladding system he concluded too that the provision and nature of fire barriers and cavity width

00:36:15 barriers and cavity width needed to be considered finally he concluded the clear need for full-scale testing of performance and fire for what he termed rational design of cladding systems

00:36:30 it is important to note that within his overall paper connolly highlighted in his discussion for results for surface spread of flame over the over the facade the following two key

00:36:42 over the facade the following two key points

00:36:43 points connolly states it is clear that the bs-476 part six and seven tests do not accurately reflect the fire hazards that may be associated with clouding systems

00:36:54 clouding systems reasons may include the fact that the flame movement in a real cladding fire is in the vertical direction as opposed to the horizontal direction in the test

00:37:05 to the horizontal direction in the test secondly he states that it is clear from experimental work undertaken at cartington that a clouding material achieving a class naught rating may suffer extensive surface burning

00:37:20 on the 11th of june 1999 a fatal fire occurred at garnok court in scotland this fire involved the external wall of the building as was the case with the knowlesley

00:37:32 as was the case with the knowlesley heights fire

00:37:35 on screen now is an excerpt from the parliamentary inquiry into this fire firstly the inquiry references the previous fire at nosley heights it then appears to reference the conley

00:37:47 it then appears to reference the conley tests in 1994 as i have just presented this inquiry then goes on to state bre proceeded to develop an appropriate full-scale fire test

00:37:58 full-scale fire test known as a test for assessing the performance of extending external clouding systems this test was submitted to the detr in 1996.

00:38:09 submitted to the detr in 1996. this test standard which had been submitted to the detr prior to the fire had not been adopted into the approved document b at the time however in the garner

00:38:20 at the time however in the garner conquiry

00:38:21 conquiry detr themselves stated that going forward

00:38:24 forward this test will be referenced in approved document b and that it was intended that had become a british standard

00:38:36 the inquiry has disclosed to me one test standard created by the bre in 1996 titled cr213

00:38:47 in 1996 titled cr213 the inquiry has also given to me a second test standard created by the bre in 1998 one year before the garnok fire this is called fire note 3.

00:38:59 this is called fire note 3. neither of these documents were publicly issued by the bre and the authors were morris caldwell connolly smith and andrews noting morris only worked on

00:39:10 and andrews noting morris only worked on fire note 3. i've compared these two bre documents and there's no material difference between them however one month following the garner court fire in 1999 the bre published another

00:39:24 in 1999 the bre published another large-scale clouding test document titled fire note 9 they should not be confused with fire note 3.

00:39:47 i have reviewed the test rig in these three

00:39:50 three publications and there is no material difference between them so i will now only refer to fire note 9. but i have compared it right back with

00:40:01 but i have compared it right back with rogowski's work in 1988 and connolly's work in 1994 as i wanted to understand how fire note 9

00:40:10 9 had been adapted over the years and i wanted to know if any fundamental issues observed in those founding experiments have been either retained or omitted

00:40:22 have been either retained or omitted fire note 9 was written by s caldwell and d smith of the bre

00:40:29 i have provided in the script to my slide information on the dimensions of the test rig which were in general the same as rogowski and connolly's test rig the

00:40:42 test rig the file fire note 9 rig did contain a wing wall which i will explain later whereas rogowski and connolly's test rig did not importantly

00:40:54 test rig did not importantly fire note 9 does not include windows in the test rig whereas rogowski and connolly did

00:41:05 the proposed crib in fire note 9 9 was very similar to rygayskiy and somewhat similar to dr connolly's experiments again an extensive read of these publications as

00:41:17 extensive read of these publications as needed

00:41:19 needed fire note 9 contained pass fail criteria for a proposed full-scale fire test these were a fire test would fail if the temperature rise above ambient

00:41:31 temperature rise above ambient 5 meters above the top of the combustion chamber

00:41:34 chamber exceed at 600 degrees celsius for at least 30 seconds within 15 minutes of the start time these pass fail criteria continued into

00:41:45 these pass fail criteria continued into later versions of br 135 with additional failure criteria introduced in the third version of br135

00:41:56 this is important because fire note 9 was first referenced in approved document b 2000 as an alternative means for complying with the building regulations

00:42:07 complying with the building regulations for external surfaces this aligns with what detr had said to the garnok inquiry years later in 2002 fire note 9 was

00:42:19 years later in 2002 fire note 9 was converted into a british standard british standard 8414 part 1 as shown on the slide here the approved document b was not updated

00:42:31 the approved document b was not updated to refer to this british standard at that time there were minor changes made to the test rig for the publication of the british standard these included

00:42:42 of the british standard these included the main wall width being reduced from 2.8 to 2.6 meters this british standard did not contain pass fail criteria for the fire tests

00:42:53 pass fail criteria for the fire tests however instead the second edition of br 135

00:42:57 135 was published again approved document b was not

00:43:01 was not updated to refer to this this second edition was authored by brian martin and sarah caldwell

00:43:09 caldwell annex a of the second edition contained the performance criteria and classification method of british standard 8414 part 1. the performance criteria were

00:43:22 part 1. the performance criteria were unamended when compared with those presented in fire note 9.

00:43:28 from 2005 onwards various amended versions of bs 8414 and the classification method publication br 135 were made and i have listed them

00:43:41 135 were made and i have listed them here on this slide

00:43:47 i will now explain both the british standard test method and the br 135 classification method in the following slides i will explain the fire test procedure first and then the classification method

00:44:00 first and then the classification method in the same style as all the other tests i've explained to you today

00:44:10 [Music]

00:44:13 first the tests

00:44:19 british standard eight four one four is a two-part british standard the scope of both is defined as a test method for determining the fire performance characteristics

00:44:30 performance characteristics of non-load-bearing external clouding systems

00:44:34 systems when exposed to an external fire under controlled conditions the fire exposure is representative of an external fire source or a fully developed post flash over

00:44:46 or a fully developed post flash over fire in a room venting through an opening such as a window aperture that exposes the cladding to the effects of external flames or from an external fire source

00:44:59 or from an external fire source part one shown on the left image on the screen

00:45:03 screen is the test method for non-load-bearing external cladding systems when applied to the masonry face of a building

00:45:10 building so this scope includes rain screen over cutting systems and external wall insulation systems when applied to the face of a building part two on the right of the screen

00:45:23 part two on the right of the screen is the test method for non-load-bearing external cladding systems fixed to and supported by structural steel

00:45:32 steel frame its scope includes curtain walling infill panels and insulated composite panels

00:45:39 panels fixed to and supported by a structural steel frame so the primary difference between the two standards is the substrate and framework of the final clouding

00:45:50 and framework of the final clouding system

00:45:52 system the purpose of the test is to evaluate the ability of the system to resist the propagation of the fire upwards or penetration through the system part one was the

00:46:03 through the system part one was the relevant standard for grenfell tower

00:46:09 br 135 contains two annexes and each provides performance criteria to be observed and measured during the eight four one four tests annex a

00:46:19 annex a and annex b address bs8414 parts one and two respectively

00:46:32 regarding the test rig used in the british standard test the test apparatus consists of combustion chamber in which a fuel source is located at ground level

00:46:43 ground level with an opening area of two meters by two meters the chamber is positioned such that the fire can project through the opening at the base of the main vertical test

00:46:54 at the base of the main vertical test wall

00:46:55 wall there are two eight meter high test walls arranged at 90 degrees to represent the inner angle of a corner the test specimen on the main wall must

00:47:07 the test specimen on the main wall must be a minimum of 2.6 meters wide when measured from the corner and a minimum of 6 meters in height when measured from the top of the combustion chamber the return wall must be a minimum of 1.5

00:47:20 the return wall must be a minimum of 1.5 meters wide and 8 meters in height british standard 8414

00:47:26 8414 states that the test specimen shall include all relevant components assembled and installed in accordance with the manufacturer's instructions where clouding systems are defined as

00:47:39 where clouding systems are defined as includes sheeting rails fixings cavities insulation and membranes coatings flashings are joints this is provided at note one of the

00:47:50 this is provided at note one of the definition of external clouding systems

00:47:58 during the test two types of data are recorded

00:48:01 recorded temperature and visual observations of significant events first i will explain how temperature is measured

00:48:09 measured an array of thermocouples are located on the exterior surface of the clouding system

00:48:14 system at 2.5 meters and 5 meters above the test opening thermocouples do not make direct contact with the cladding

00:48:24 cladding and are positioned at a distance of 50 millimeters from the surface those located at 2.5 meters are considered representative of a level one those located five meters

00:48:37 of a level one those located five meters above the combustion chamber are considered representative of a level two

00:48:44 two thermocouples on the main wall are positioned on the center line of the wall

00:48:48 wall and then at 500 or 1000 millimeters either side of this center line this creates an array of five thermocouples at level one and level two on the main wall

00:49:01 and level two on the main wall thermocouples on the return wall are positioned at 150 600 and 1050 millimeters from the junction with the main wall

00:49:12 from the junction with the main wall this creates an array of three thermocouples at two heights on the return wall internal thermocouples are also placed within the cladding system in

00:49:23 within the cladding system in any combustible layers that are greater than 10 millimeters in thickness or more these internal thermocouples are positioned at level two only all internal thermocouples are

00:49:35 only all internal thermocouples are positioned at the midpoint of the layer and temperature measurements taken for the duration of the test as shown in the image on the right of the screen in this example on the right hand side

00:49:47 in this example on the right hand side there is an external thermocouple by the gray layer and two additional internal thermocouples one at the midpoint of the cavity and one at the mid depth of the insulating material

00:50:03 if the external cladding system does not offer any protection to openings and practice

00:50:08 practice i.e there are no cavity barriers around the openings then the interface between the test specimen and the combustion chamber must also remain unprotected this is as stated at note 1

00:50:21 unprotected this is as stated at note 1 to the definition of external clouding systems in the british standard if horizontal and vertical joints are incorporated into the external cladding system the

00:50:32 into the external cladding system the test specimen shall be representative of these joints in practice if the size of panels in their end use are smaller than the area of

00:50:40 of wall represented by the apparatus there may be multiple horizontal and vertical joints

00:50:47 joints on the left hand image is an elevation of a panel system and i have over marked the joints in orange on the right

00:50:58 the fuel source used in the test is a timber crib comprising alternating layers of softwood sticks the crib has a plan area of 1.5 by 1 meter

00:51:09 meter and a height of 1 meter the crib is ignited with strips of fibre board soaked in white spirit and is designed to represent a nominal total heat output of megajoules

00:51:22 output of megajoules with the peak release rate of three megawatts

00:51:26 megawatts to give that size some comp some context in in the eurocode one action on structures the typical reset apartment is assumed

00:51:37 the typical reset apartment is assumed to contain a fire load density of 780 megajoules per meter squared this translates approximately into an area of 5.7 meters squared when fully

00:51:49 area of 5.7 meters squared when fully alight

00:51:50 alight i have over marked a 5.7 meter squared area

00:51:53 area in the drawing of flat 16 on the image on the left of the slide just to give a sense of scale

00:52:05 just to give a sense of scale secondly visual observations of significant events are to be recorded the standard states the times of significant events such as a change of flaming conditions

00:52:17 such as a change of flaming conditions and mechanical behavior of the clouding systems are to be recorded especially detachment of any part of the cladding system whether flaming or otherwise or any other fire penetrations through

00:52:29 other fire penetrations through fire stops incorporated within the clouding system a continuous audio visual record of the full height of the test face is taken throughout the test to allow

00:52:40 is taken throughout the test to allow for analysis cameras should provide coverage of the entire external surface of the material in addition internal

00:52:49 internal audio visual cover coverage is required for tests

00:52:53 for tests to the part 2 standard to assess any burn through to the internal face of the cladding system

00:53:04 five minutes before the crib is ignited the thermocouples and audio visual equipment begin taking measurements the crib is ignited temperatures and visual recordings are made from five

00:53:15 visual recordings are made from five minutes before ignition until 60 minutes after ignition the crib is allowed to burn for 30 minutes at which point it is extinguished the test continues for a further 30

00:53:28 the test continues for a further 30 minutes during which time any observed flaming on the test specimen is allowed to continue burning the test is stopped early if at any point during the test

00:53:39 point during the test flames extend above the test apparatus or if there is a risk to the safety of personnel within the test facility this stopping of the test aspect was only introduced

00:53:50 only introduced into the test standards in 2005. it was not cited within part one of british standard 8414 until 2015 when both parts one and two

00:54:02 until 2015 when both parts one and two were updated the reference to this early termination was added

00:54:07 was added to the third edition of br135 in 2013 and this is important to note when reading historic test reports

00:54:22 i'm just going to show the video first

00:54:28 in this short video we see a test being carried out you can see that the fire in the crib in the combustion chamber has ignited with flames projecting above the combustion chamber and impacting on

00:54:40 the combustion chamber and impacting on the cladding assembly several meters above the graphs of temperature shown on the right here are measurements taken at level two so five meters above the opening

00:54:52 five meters above the opening these are measured by thermocouples external to the clouding surface inside the cavity between the cladding and insulation and within the insulation product itself and i'll explain

00:55:03 and i'll explain this later a test report should be provided for each test undertaken including if the test is terminated early

00:55:14 early and this is required by the british standard it should include a full description of the cladding system together with details of materials and components used and fixing details details of the

00:55:27 and fixing details details of the results of the test and observations we discussed

00:55:30 discussed earlier and a record of visual observations made during the test including flaming and mechanical response

00:55:37 response supplemented by suitable photographic records

00:55:41 records for tests to part two full details of the test frame must also be included it's worth noting that by the time of the grant for fire the bre were the uk's only testing lab

00:55:53 the bre were the uk's only testing lab with accreditation to undertake british standard 8414

00:56:00 testing finally i will summarize the performance criteria and classification method set out in the classification standard

00:56:11 three editions of br135 have been published by bre the first was rigawsky's work the second in 2003

00:56:19 in 2003 and the third in 2013.

00:56:24 br 135 makes clear the application of its classification only applies to the system as tested and detailed

00:56:33 detailed in the classification report when specifying or checking a system therefore it is important to check that the classification documents cover the end use application

00:56:47 br 135 focuses on three main performance criteria

00:56:51 criteria external fire spread internal fire spread

00:56:54 spread and mechanical performance failure due to external fire spread is deemed to have occurred if the temperature rise above ts that's

00:57:06 if the temperature rise above ts that's the initial ambient temperature before the crib is ignited

00:57:09 ignited of any of the external thermocouples at level two

00:57:13 level two and it exceeds 600 degrees celsius for a period of at least 30 seconds and within

00:57:19 within 15 minutes of the start time ts this start time isn't the point at which the crib is ignited it is defined as the point at which any thermocouple at level 1

00:57:31 thermocouple at level 1 equals or exceeds 200 degrees celsius for a period of 30 seconds if the temperature of 600 degrees

00:57:39 degrees celsius is not exceeded within 15 minutes

00:57:43 minutes then the system passes the external fire spread performance criteria

00:57:51 to explain the context of this 15-minute window

00:57:54 window relied upon in the classification method i have as an example marked up the level 2

00:58:01 2 external temperature versus time graph taken from a recent mhclg test report by the fire protection association and the references are provided here

00:58:12 and the references are provided here this was a part one test of a hpl panel over a class a1 insulation material the grey dashed line shown on the screen now indicates 600

00:58:25 shown on the screen now indicates 600 degrees above ambient temperature the blue dashed line indicates 15 minutes

00:58:31 minutes after ts the area in the green box indicates the envelope of time and temperature within the test that br135 considers for external fire spread performance

00:58:44 external fire spread performance you can see the peak external temperatures in this particular test do not occur in this window and instead occur later at around 30 minutes after ts

00:59:00 [Music] next failure due to internal fire spread is deemed to have occurred if the temperature rise above ts of any of the internal thermocouples at

00:59:11 of any of the internal thermocouples at level 2

00:59:12 level 2 exceed 600 degrees c for a period of at least 30 seconds within 15 minutes of the start time an example graph taken from br 135

00:59:23 example graph taken from br 135 is shown at figure a6 on the screen now please note the clear peak occurring in this graph at 15 minutes after ts [Music]

00:59:34 [Music] again to give some context regarding the 15 minute

00:59:38 15 minute window relied upon in the br 135 classification method i have assessed the level 2 cavity temperature versus time graph from those mhclg tests again

00:59:49 mhclg tests again but considering the measured internal fire spread data again the gray dashed line indicates 600 degrees celsius above ambient temperature limit

01:00:00 temperature limit and the dash blue line indicates 15 minutes after ts limit you can see in this particular particular test the measured peak internal temperatures

01:00:11 the measured peak internal temperatures occurred at around 32 minutes after ts

01:00:19 i decided to take this analysis a little further and i've analyzed 21 bs 8414 test reports 12 were tested to part 1 and 9 to part

01:00:31 12 were tested to part 1 and 9 to part 2.

01:00:33 2. of these 21 seven were the mhclg tests undertaken after the grantful fire one of which was the hbl test i've referred to already and the remaining thirteen were from

01:00:45 and the remaining thirteen were from tests disclosed to the inquiry by kingspan celetex and ciderise on screen now are individual dots representing the peak temperatures measured at level 2

01:00:57 measured at level 2 in each of the 21 tests on the time they occurred

01:01:01 occurred i have also colored the graph to indicate and read what would be considered a failure to meet the current br 135 performance criteria as shown in the red

01:01:14 performance criteria as shown in the red area there on the left hand side of the blue dash line

01:01:20 if one takes the performance criteria as not exceeding 600 degrees c so the red dash line in 30 minutes instead

01:01:30 instead of the current 15 minutes please note the increased number of failed tests above the dash red line the panel should consider if modern

01:01:41 the panel should consider if modern materials and modern facades typically reach peak flame and combustion within 15 minutes of the start of the bs-84

01:01:52 bs-84 test

01:01:58 but back to the third performance criterion in the bre classification method which is mechanical performance no failure criteria are set in br 135

01:02:10 no failure criteria are set in br 135 annex a from mechanical performance when considering test data from part one reading from the extract shown on the screen no failure criteria have been set for

01:02:21 no failure criteria have been set for mechanical performance however ongoing system combustion following extinguishing of the ignition source

01:02:28 source shall be included in the test and classification report together with details of any system collapse spoiling delamination flaming debris or pool

01:02:39 delamination flaming debris or pool fires

01:02:40 fires the nature of the mechanical performance should be considered as part of the overall risk assessment when specifying the system this extract tells us that occurrences

01:02:51 this extract tells us that occurrences of mechanical failure such as system collapse or delamination can be recorded in the test report but do not constitute a failure when classifying in accordance with

01:03:02 when classifying in accordance with br135

01:03:07 and finally references to this test and and classification method during the grenfell refurbishment

01:03:17 these were referred to as part of the primary refurbishment works on screen now is the celatex rs 5000 data sheet i've marked up the sections that refer

01:03:29 i've marked up the sections that refer to british standard 8414 and br 135

01:03:37 page 3 of the datasheet provides the following description of the celetex assembly that was stated as tested

01:03:44 as tested and formed part of the classification report

01:03:47 report that system was not installed on grenfell tower

01:03:53 [Applause]

01:03:56 to some to just to make a final point um the image on screen now shows the sizes of the small scale test requirements for

01:04:07 of the small scale test requirements for the sample sizes to determine material performance as we have discussed today the final item on the far right is representative of the smallest size

01:04:20 is representative of the smallest size flat panel of renault bond 55 pe that are kind of archonic sold as referenced in the bba agreement certificate i have redone that slide including

01:04:34 redone that slide including the 841 fortes which is the very large sample

01:04:37 sample before the archonic panel

01:04:43 i have also summarized the test duration for each one of the tests i have told you about today and that ends my um

01:04:55 and that ends my um explanation of the cladding tests and i was just going to provide some final points to consider after what has been a very detailed

01:05:06 after what has been a very detailed presentation

01:05:09 throughout this presentation i have made reference to various issues i thought the panel might like to consider and i wanted to sum them up now after three three hours or so of

01:05:21 now after three three hours or so of communicating some very detailed information that the reaction to fire testing regime is associated with internal room fire phenomena yet they

01:05:32 internal room fire phenomena yet they are relied upon in the statutory guidance document to reduce the surface's susceptibility to ignition

01:05:39 ignition from an external source and to reduce the danger from fire spread up the external face of the building that the national reaction to fire tests includes one surface spread of flame

01:05:51 includes one surface spread of flame test and this measure spread in the horizontal direction that the external surface and the insulation have been considered separately for several decades and the class note has been the

01:06:04 decades and the class note has been the reference for the external surface performance since 1965 that the definition of class naught has degraded with time reduced from non-combustible materials

01:06:16 reduced from non-combustible materials throughout and also the role of the substrate removed from the statutory guidance document

01:06:23 document yet both the national and european reaction to fire testing regime very carefully set out rules regarding substrates and their impact on fire performance when testing

01:06:35 when testing and that the window of assessment of the data from the large scale british standard 8414 test is early in the fire

01:06:43 the fire and maybe before peak temperatures are measured

01:06:46 measured for relevant clouding materials overall though i hope i have communicated the intricacies of each standard test the careful explanation provided in each

01:06:59 the careful explanation provided in each test standard of the physical features of the test rig how each test rig has been created to represent

01:07:07 represent specific fire performance characteristics and how specific parameters have been derived for each test with a requirement then for very careful analysis

01:07:18 analysis of the data produced from these tests extensive work seems to have gone in to defining these tests

01:07:26 tests how to derive results from them and how to rely on them to classify construction products and materials it would be of considerable interest to hear the perspective

01:07:37 perspective from those that created and monitored the reaction to fire test standards in this country those companies that carried out the tests those companies that issued classification reports

01:07:49 classification reports and those companies that issued certificates their understanding of how those parameters were derived how those parameters were relied upon and how relevant

01:08:00 and how relevant they considered them to be to the far performance of external walls thank you well dr lane thank you very much indeed uh it's very interesting i'm not there

01:08:12 uh it's very interesting i'm not there to digest those as requested yes yes it's great yes mr chairman i mean there's a huge amount of work going into that to make it quite so clear so i'd like to extend my thanks and

01:08:25 so i'd like to extend my thanks and i'm sure those behind me would as well to dr lane and her team for putting together such a comprehensive and clear presentation yeah certainly well and we're all very grateful for the enormous amount of work that's been

01:08:36 the enormous amount of work that's been put in and for a very clear exposition yes okay okay right thank you so we could let dr lane go can we yes we say goodbye to dr lane for now i'm sure she'll be back yeah

01:08:48 for now i'm sure she'll be back yeah okay all right thank you very much indeed and and thank you tom for your assistance

01:08:55 yes and then we start with the first of the celetex witnesses tomorrow mr room um who mr millet will be questioning yes and that's it for today that is it for today we've got an early finish right

01:09:06 today we've got an early finish right we don't get those very often so we don't no good thank you very much so it's um we'll break there and we'll resume at 10 o'clock tomorrow when we shall hear from the first of the celtics witnesses yes thank you good

01:09:17 witnesses yes thank you good thank you very much turn and talk tomorrow

01:09:39 you