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Cavity Walls

When planning for separating walls in new build houses and flats, architects and contractors have to make sure that the wall meets Requirement E1 of Approved Document E for acoustic performance standards, meaning they provide “reasonable resistance to sound from other parts of the same building and from adjoining buildings”.

Robust Details approved cavity walls exceed E1, and new builds using robustdetails® patterns do not need pre-completion testing. However, one of the most important requirements is that the right materials are used and the build is completed to a high standard.

One top tip to bear in mind when constructing loadbearing masonry is to avoid mortar bridging. Cavity masonry walls have a cavity for good reason and it is not to provide a home for excess mortar or general debris! Mortar (and debris) accumulating within the cavity, on cavity insulation and wall ties can seriously undermine the sound insulation performance of a separating wall. With a clean cavity, good sound insulation can be expected.

Cavity masonry walls are subject to pre-completion testing unless a robustdetails® construction is used. Remember to check the compatibility of separating walls with separating floors – detailed information on every wall, floor and roof build is available in the robustdetails® handbook.

If you have any techncial enquiries please do not hesitate to contact our technical team on 03300 882140 or email:

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