QUALICOAT UK & IRELAND
Architectural Powder Coatings - The Facts About Fire
By Angus Mackie - QUALICOAT UK & Ireland Chairman
There has been a great deal of discussion that has taken place of late over the combustibility of the external envelope of some of our high-rise dwellings where aluminium composite panels ( ACM ) containing flammable cores have been used . These panels are in the process of being removed and replaced to meet stringent new standards . Insurance companies , mortgage providers and other property stakeholders have also had their part to play to mitigate
Anodised Aluminium Sheet - tested to BS 8414
Pre-Coat Aluminium Sheet - tested to BS 8414 risk and have forced building owners to check for ACM and other issues such as areas of timber decking . All this will ensure a safer building stock for our city ’ s high-rise dwellings .
The surface spread of flame on a high-rise dwelling can cause fire to spread quickly from floor to floor and legislation is now in place to ensure construction designs slow down the spread of a fire through the building envelope , or to stop it altogether , by correctly specifying the materials used in the building project . As a result , new and refurbished buildings deemed to be high-rise , over 18m in England ( 11m in Scotland ), will be considerably safer .
Of late members of QUALICOAT UK & Ireland have seen a rising number of powder coating specifications that request an ‘ A1 ’ classification for combustibility under BS EN 13501-1 . When traced back through to the specifier , the origin of this requirement largely stems from property stakeholders who are misguidedly attempting to mitigate their risk by exceeding the current guidance , standards and legislation currently available . This can add both complexity and costs to projects without any benefit or reduction of risk .
When applied at standard industry thicknesses , architectural Polyester Powder Coating ( PPC ) achieves an ‘ A2-s1 , d0 ’ classification . This classification is required for compliance to the amended Building Regulations 2010 ( Approved Doc B : Fire Safety ) Nov 2018 and accepted as providing the necessary protection from the surface spread of flame on high-rise construction and other legislated buildings .
Ultimately , PPC does not promote combustibility or fire spread when tested to BS EN 13501-1 . This is further supported by the testing required for London Underground approval , often lauded as a barometer of fire safety . This requires compliance to EN 45545 , where spread of flame is measured objectively ( ISO 5658-2 ) unlike BS EN 13501-1 which involves visual assessment only . Furthermore , PPC smoke production is extremely low or non-existent ( s1 ) with no flaming droplets ( d0 ). On the chart of combustibility , ‘ A2-s1 , d0 ’ sits just under the ‘ A1 ’ classification .
It is important to assess the cladding system holistically and not just the performance of the constituent parts under BS EN 13501-1 .
The predominant fire test for the whole external cladding system is BS 8414 . This provides a route to compliance for buildings over 18m that are outside the scope of Part B regulations . This requires materials to meet the performance criteria given in BRE report BR 135 which measures whether the cladding build up is deemed safe for buildings at elevated height . The test itself involves a 9m
10 AUGUST 2021 read online : www . surfaceworld . com