APPENDIX A
The 60-minute test measures and evaluates fire spread and mechanical performance and includes a 30-minute observation to evaluate propagation behaviour post-exposure.
It is not possible to use large-scale tests to demonstrate compliance where there is a ban on combustible materials in relevant buildings. However, even within a single structure, the detailing and cladding systems could vary. Therefore, as part of the review of the standards, the government commissioned the development of a new standard, BS 9414. Dr Mostafa Jafarian, Principal Certification Engineer – Façades and Structures, Warringtonfire wrote: “BS 9414 was developed with the remit of having harmonised rules for extending the scope of application of cladding systems tested to the BS 8414 test series. It would also ensure that a new system could not record temperatures higher than the tested system. The new test regime will allow for previously tested products to remain valid, while extending the scope of the test to allow testing of newer products with more applications. This approach not only accommodates the need for the practical aspect of the test, but also makes sure that the change in detailing would not have an adverse impact on the overall performance of the system.” trada.co.uk/news/changes-to-the-test-and-requirements-for- fire-and-cladding/
BS 8414-1:2020 Fire performance of external cladding systems. Test method for non-loadbearing external cladding systems fixed to, and supported by, a masonry substrate. BS 8414-2:2020 Fire performance of external cladding systems. Test method for non-loadbearing external cladding systems fixed to, and supported by, a structural steel frame. BS 9414 FIRE PERFORMANCE OF EXTERNAL CLADDING SYSTEMS The standard provides guidelines on what variations are possible to cladding systems tested in line with the existing standards BS 8414-1 and BS 8414-2. It clarifies when systems should be subjected to a full- scale test or where the relevant results of existing test(s) can be used to understand the behaviour of the system. It does so by setting out procedures and rules with which to evaluate variations and changes to products and systems tested in accordance with BS 8414. Where appropriate, the draft standard also defines options and limits for preparing reports based on the direct and extended application criteria provided. The standard covers the following systems: • Insulated and ventilated rain screens • External thermal insulated composite systems (ETICs) • Self-supporting double-skin metal-faced insulating (sandwich) panels Currently, Building Regulations and Approved Document B (for England) prohibit the use of combustible insulation and boards in external walls for certain types of buildings (relevant buildings) with a storey that is 18m or more above ground level.
FIRE PERFORMANCE OF EXTERNAL THERMAL INSULATION FOR WALLS OF MULTISTOREY BUILDINGS, THIRD EDITION (BR 135) Performance criteria for assessing cladding systems
tested using BS 8414 is contained within BR 135 Fire performance of external thermal insulation for walls of multistorey buildings. It is important to note that
the classification applies solely to the specific external façade system that has been tested.
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