A typical value given for the heat of combustion of phenolic foam is 29 MJ/kg, nearly ten times higher than the limited combustibility criterion. Like the rest of the Kooltherm range, K15 is a phenolic foam board. In a Freedom of Information response of 4 July 2018, the University of Essex stated that the insulation employed on the Southend building was ‘Kingspan Kooltherm insulation board’ and has since confirmed it to be Kingspan’s rainscreen product Kooltherm K15. ![]() As stated earlier, the heat of combustion must not exceed 3 MJ/kg if the material is to be Euro Class A2 and of ‘limited combustibility’. A simplified version of this procedure has been employed by the BRE for its post-Grenfell tests of ACM samples. Screenshot from an ISO 1182 test, obtained from 's YouTube video of the testĪs an alternative, under EN ISO 1716, the heat of combustion (calorific value) of the product may be measured in a bomb calorimeter. Under the European classification system, for example, to achieve Class A2 and thus ‘limited combustibility’, the temperature rise must not exceed 50 ☌, the mass loss must not exceed 50%, and the period of any sustained flaming must not exceed 20 seconds. This Reaction to Fire class may be achieved in two main ways, through two types of fire test.įirst, under BS 476 part 4 or part 11, or under EN ISO 1182, a material or product is placed in a 750 ☌ furnace for a period of 30 minutes (BS 476-4), up to 60 minutes (EN ISO 1182) or up to 120 minutes (BS 476-11), with measurements taken of the rise in furnace temperature, the mass loss of the specimen, and the period of any sustained flaming. Under AD B Vol.2 12.7, insulation products used in the external wall construction should be of ‘limited combustibility’, as defined in Appendix A.9 and Table A7. The insulation installed behind the panels, however, was and remains another matter. In both cases, as the Diagram shows, the requirements were satisfied. Standard panels, with an Index (I) of 19, just below the limit of 20, were employed below 18 metres. Fire Retardant Trespa panels, tested and classified to national Class 0, had been specified above 18 metres. ![]() At the time of construction, however, according to information supplied in response to my enquiry to the University of Essex, who treated it as a Freedom of Information request, the Trespa panels were fully compliant with the requirements of Approved Document B Vol.2, 12.6 and Diagram 40e. © John Allan - /p/2276927 – cc-by-sa/2.0īarring a successful large-scale BS 8414/BR 135 test and classification of the entire cladding system, including the insulation and supporting framework, such cladding can no longer be installed, under the post-Grenfell government guidance, on buildings above 18 metres. The Southend building with its distinctive 'Lego-style' structure and cladding One HPL product was found to have a heat of combustion (fuel energy) of 20.4 MJ/kg, nearly seven times the upper limit of 3 MJ/kg for materials of ‘limited combustibility’, as defined by Approved Document B ‘Fire Safety’. ![]() The cladding is a ‘Trespa’ High Pressure Laminate (HPL) product, which is combustible by nature, being composed of plastic reinforced with wood fibre. Students from both the University of Essex and South Essex College reside in the brightly coloured accommodation situated in University Square, Southend, and pictured to the right.
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