Powerlon ThermaPerm is a new engineered breather membrane with a thermo-reflective layer for improved energy performance. ThermaPerm’s foil layer helps to reduce the transmission of heat both from the exterior and interior, reflecting warm weather heat and reducing heat loss in winter months. The CE marked membrane offers good breathability and a superior W1 rating for water tightness, and comes in two roll widths.

The energy-efficient ThermaPerm membrane is suitable for both wall and pitched roof installations. While particularly useful in new timber frame construction, it can also result in positive reductions to the U-value of renovations and conversions of existing properties.

U values (measured in W/m²K) express the thermal conductivity of building materials and installations; the lower the value, the more energy efficient the building. Buildings Regulations Approved Document L (Conservation of Fuel and Power) states that new buildings should have a U value of 0.28 W/m²K for walls, 0.16 W/m²K for pitched roofs with insulation at ceiling level and 0.18 W/m²K for flat roofs and for pitched roofs with insulation at rafter level.

To maximise the energy savings, Thermaperm should be used in conjunction with a thermo-reflective vapour control layer, such as Powerlon UltraBlock, installed on the warm side of the insulation. When both traditional unfaced wall breathers and VCLs are replaced by thermal resistant versions, there can be a significant overall reduction in the U value.

Powerlon ThermaPerm and Powerlon Ultrablock are produced by Industrial Textiles & Plastics (ITP) of North Yorkshire, manufacturers of protective materials for buildings and construction.

More details here https://www.itpltd.com/en/product/wall-membranes