Membrane designed to insulate attached houses

Engineers in Scotland have developed a thin membrane insulation specifically for reducing heat loss in attached houses.

The product, dubbed Wallcap, was developed by Edinburgh Napier’s Institute for Sustainable Construction (ISC). It is currently being manufactured and sold through Icopal, based in Manchester.

New building regulations introduced in Scotland, England and Wales on 1 October changed thermal and acoustic insulation requirements for housing.

Wallcap’s developers say their product is the first of its kind to provide a thin membrane solution for reducing heat loss in attached houses.

The product incorporates three elements involving an alumni-bitumen-based 3mm membrane manufactured by Icopal, a pre-fitted cavity fire stop from Siderise Lamatherm in Wales and a metal connector for gripping the wall head from Scottish-based Cullen.

Prof Sean Smith, who was principal investigator for the ISC team, said housebuilders can expect no heat loss − a 0.0U value − when the membrane is used with a full fill mineral wool for cavity.

‘Full fill on its own cannot get the 0.0U value,’ he said.

Prof Smith said Wallcap has been on the market for a few months but the new regulations on 1 October have increased interest in the product. Wallcap sells for a list price of about £15 a linear metre.

Wallcap was tested with developers and house builders in trial sites at the Building Performance Assessment Centre (BPAC) Hangar 17 − a full-scale test facility in Fife for new construction product technologies.

Prof Smith said that the results of those tests were very promising.

‘Trial sites show some superb thermal images with no heat loss appearing at the walls or party wall roof junctions,’ he said.