Cavity Fire Seal

The Cavity Fire Seal provides a high performance fire resistant cavity seal.


Sealmaster Cavity Fire Seal is suitable for use in cavities from 20 - 50mm wide, in all timber framed constructions. it may be used in a horizontal or vertical plane, i.e. at floor level or around window atertures. It is mounted directly to the inner cavity wall or on a splayed, treated softwood batten, if necessary, to provide a clear gap of 10mm between the seal and cavity outer wall. This batten may be continuous or interrupted by vertical battens, as needed.

The batten should be fixed through to the structure with 75mm galvanised nails at 250mm centres, staggered top to bottom, the seal is then fixed directly to the batten with 30mm galvanised nails, staggered at 150mm centres. Care should be taken to ensure that joints in the batten and cavity fire seal and / or fixings do noy coincide. The Sealmaster Cavity Fire Seal does not require any intumescent mastic to joint or to bed against, nor does it require any paint or other protective coatings.


The Sealmaster Cavity Fire Seal fulfills all of these criteria with ease and provides a permanent, maintenance free solution to what would be a very dangerous problem. It actually exceeds the design brief by providing over 60 minutes fire integrity. The seal comprises of a length of our flexible graphite based intumescent material, set into a stainless steel carrier system. This results in both the materials and their fixings being fully resistant to water, damp, humidity, heat and cold and even frost.


Part 1: 1999 (replacement for BS476 Part 22) andwitnessed by representatives of Chiltern Internnational Fire and the NHBC. The test was terminated after 69 minutes without failure. Test report available on request.


The Cavity Fire Seal is approved by NHBC for use in timber framed constructions, as detailed.

Product ref: CFS

Product categories: Structural Fire Seals



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