Fire Classification of Bonded Insulation
Specifiers ’ interactive guide to
Materials
acoustic , fire and thermal insulation
A ROCKWOOL Technical Bulletin
Following the Grenfell disaster , a ban on combustible materials in the external walls of relevant buildings over 18m came into force in 2018 * , reinforcing the importance of non-combustibility and regulatory compliance in all areas of building construction .
Construction elements attached to the façade - such as upstands , balconies and terraces - fall within the scope of this ban . However , to develop specific solutions for these applications , some manufacturers have adopted techniques that include the bonding of insulation materials to create a composite board – which raises the potential for an inaccurate reaction-tofire rating to be claimed on the finished product .
In response , ROCKWOOL has written a technical bulletin to give advice on the use of these composite products , and the potential impact of these on a building ’ s compliance with both Approved Document B ( ADB ) and the combustible ban ( the need to achieve Euroclass A2-s1 , d0 or better ).
A tested bonded solution
ROCKWOOL HARDROCK ® UB34 is a noncombustible insulation solution designed specifically for parapet walls and upstands on flat roofs . It comprises of a dense 50mm slab of ROCKWOOL stone wool insulation bonded to a rigid 6mm fibre cement board , and is suitable for use on buildings over 18 metres that are affected by the ban on combustible materials .
ROCKWOOL has ensured that HARDROCK UB34 is tested as a finished composite product , and it has proven to achieve Euroclass A2-s1 , d0 .
More information about ROCKWOOL HARDROCK UB34 is accessible through the Flat Roof Resource Hub on the ROCKWOOL website ( rockwool . link / pbctoday ), and its reaction-to-fire certification is available on request .
Understanding Euroclass
The simplest way to determine the combustibility of a building product is by checking its Euroclass reactionto-fire rating .
A product ’ s Euroclass rating factors a comprehensive set of characteristics , including ignitability , flame spread , heat release , smoke production and propensity for producing flaming droplets and particles .
Only products achieving classifications ‘ A1 ’ and ‘ A2-s1 , d0 ’ can be used where the combustible ban applies . In terms of bonded insulation materials , it is not necessarily the case that two A1 or A2-s1 , d0 component materials will bond to form an equally noncombustible product – making it essential for contractors and specifiers to seek the proper testing and certification .
*
Separate rules apply in Scotland for buildings over 11m