Celotex Isover

Insulation for Full Fill Masonry Cavity Walls

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Building two skins of masonry (brick and/or blockwork) either side of an air cavity has been the most popular method for constructing external walls in the UK for about a century. From its development to address some of the flaws of traditional solid wall construction, it has gradually evolved in response to improving insulation technology and the development of building regulations relating to energy efficiency.

In a full-fill masonry cavity wall the residual cavity between the two leaves of masonry is entirely filled with insulation. Third-party accreditation in the form of BBA certification means that the insulation is guaranteed not to allow wind-driven rain to penetrate across the cavity, ensuring that the wall retains its original function of keeping the inner leaf of the structure dry.

The building detail is for illustrative purposes only. It does not constitute advice and should not be relied upon.


Insulation products
Product Name Thickness Range Sizes Lambda BBA
ISOVER Cavity Wall Slab (CWS 32) 65-150mm Width 455mm, Length 1200mm 0.032 W/m.K Tick Icon
ISOVER Cavity Wall Slab (CWS 34) 75-150mm Width 455mm, Length 1200mm 0.034 W/m.K Tick Icon
ISOVER Cavity Wall Slab (CWS 36) 50-150mm Width 455mm, Length 1200mm 0.036 W/m.K Tick Icon