Construction membrane delivers thermal efficiency and insulation cost savings

Protect Membranes, UK producer of roofing and construction membranes, has introduced Protect TF InterFoil, a CE marked, highly reflective insulating breather membrane designed for use within a timber frame wall panel to enhance its overall thermal performance. Ideally suited to offsite and modular construction, Protect TF InterFoil features a low emissivity, vapour permeable reflective surface, using the tried and tested technology of TF200 Thermo, which can be installed either side of the insulation in conjunction with a 20mm air cavity. This means the building developer and fabricator can move from more expensive, rigid high-density boards to fibrous or EPS insulants without increasing panel sizes, thereby achieving material cost savings.

When Protect TF InterFoil is used with Protect TF200 Thermo insulating breather membrane on the external face of the sheathing board and Protect VC Foil Ultra insulating vapour control layer on the warm side of 100mm 0.032 lambda insulation within a typical 140mm deep timber stud section, the overall wall construction can achieve U-values as low as 0.18W/m2K. This meets the more onerous Fabric Energy Efficiency requirements detailed in Building Regulations Part L1A.

John Mellor, Product Manager comments, “With the ongoing material supply and price instability of PIR rigid board insulation, using Protect TF InterFoil as part of a timber frame or modular wall system offers opportunities to make meaningful material savings whilst retaining low U-values, without increasing the size of their panels. Our Technical team offers a full U-value calculation service to demonstrate how using Protect TF InterFoil can benefit the overall build.”

Available in different roll sizes, including 2.4m and 1.2m widths and 100m lengths, Protect TF InterFoil is installed with the Protect Cavit-E Tray, an insulation spacer designed to create the 20mm low emissivity airspace within the depth of the wall stud on either or both sides of a fibrous insulation.  Alternatively, EPS insulation boards from Jablite (JTWS-TF) have integral ribs on both sides which create the required airspaces.

For more details please contact Protect on 0161 905 5700, by email at or visit