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Insulation for Masonry Partial Fill Cavity Walls

Insulating a cavity wall insulates a building without impacting on internal living space.

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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 technology and the development of building regulations relating to energy efficiency.

Using rigid insulation boards in conjunction with a minimum 50mm air cavity is a tried and tested solution familiar to designers, specifiers, contractors and building inspectors alike. Partial fill cavity walls are particularly well suited to extensions of existing buildings, where the U-value targets tend to be a little less onerous. They can also form part of a whole-building solution that meets the calculated energy efficiency targets for new-build projects.

Celotex polyisocyanurate (PIR) insulation boards for partial fill solutions are sized specifically to fit standard wall tie spacing requirements. Furthermore, the low emissivity foil facing can improve the thermal resistance of the cavity, helping to meet required U-values while keeping insulation thicknesses to a minimum.


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Celotex products to consider

1200 x 450mm
0.022 W/mK

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