Warm roof new build extension consists of a polythene vapour control layer. Condensation is formed when warm moist air rises and condenses into a liquid on contact with the colder surfaces above the insulation. The idea behind a vapour control layer is to install it on the room side of the insulation so that it blocks the passage of warm moist air entering the structure.

140mm PIR tissue faced insulation is ideal for fully adhered and mechanically fixed systems. 140mm insulation has been used to create a U-value that meets the architect’s specification. Thermal transmittance, which Uvalue is also known as, is the rate of heat transfer through a structure divided by the difference in temperature across that structure. The better-insulated a structure is, the lower the Uvalue will be. The units of measurement are W/m²K.

The Flat Roofing Company
The Flat Roofing Company

Evalon VSK 1.2mm membrane self-adhered to the 140mm PIR insulation boards with an innovative and aesthetically pleasing membrane. Laps have been fully heat welded to create a 100% waterproof roof covering, with the option to have a green/blue or brown roof installed.

If you have a similar project that you believe The Flat Roofing Company can help with, don’t hesitate to get in touch with us today. Give us a call on 01202 925951, or send an email to