Cavity Insulation

Whether you’re extending your home or building from scratch, good cavity wall insulation is a must to prevent heat loss from your home.

Our range of Isover cavity wall slab insulation is flexible and easy to install, with slabs made at 455mm wide to fit standard wall tie spacing.

100mm cavity wall slab insulation is our most popular thickness, but we stock a range of sizes from 50mm up to 150mm.

What’s the difference between Isover Cavity Wall Slab (CWS) 32 and 36? Isover CWS 32 offers thermal conductivity of 0.032 W/m.K and Isover CWS 36 offers thermal conductivity of 0.036 W/m.K.