Internal Corner Xtratherm Cavity Full Fill Wall PIR Insulation 100mm- 4 no Xtratherm CavityTherm is a continuous wall insulation system. It delivers ultimate thermal performance with the added assurance of inbuilt protection from wind driven rain. It is a high performance composite board of enhanced PIR with a lambda value of 0.021 W/mK, for full fill cavity wall applications. CavityTherm has gas tight facings with one face bonded to a profiled HIPS skin during manufacture to provide a drainage plane. Dimensions : 1200mm x 450mm Area covered by 1 board : 0.54m2 Area covered by 1 pack of 4 : 2.16m2