Fire Rated Membranes
Selecting the correct membrane is vitally important when a fire rated external wall detail is required either due to the building height or the proximity of a boundary wall. Traditional membrane choices are not suitable due to amended Building Regulations which came into force on 21st December 2018. This amendment implemented the ban of combustible cladding by prohibiting the use of combustible materials anywhere in the external walls of high-rise buildings over 18 metres above ground level, containing one or more dwellings.
The guidance in Approved Document B for a habitable building over 18m states that materials in the external wall should meet the limited combustibility requirement of A2-s3, d2 or better. However, it also details within Regulation 7 those components that are exempt from the ban, which applies to the entire external wall construction:
(3) Paragraph (2) does not apply to: (g) membranes;
Membranes used as part of the external wall construction should achieve European Class B-s3, d0. Membranes are not designed to be a fire stopping material or fire break and as such are not required to achieve a Class A rating. It is important that the choice of membrane meets the requirements of both Approved Document B: Fire Safety and the Code of Practice for Condensation Control: BS 5250.
Novia manufacture a range of membranes that exceed the current Building Regulation requirements. This ensures that our customers know they are specifying and installing fully CE approved and independently certified products in their projects. Novia VC4000 FR should be used in vapour control layer applications and Novia FR for breather membrane applications.
It is very important to read and understand the installation requirements and suitability prior to specifying these types of product. Please contact the Novia technical team who can offer free guidance to help with product choice. Samples are available on request.