For What It’s Worth

The design of Styrofoam Wallmate insulation was the answer to the perennial demand for a simple way to insulate and finish basement space. The manufacturer put a 3/4-inch-deep by 11/2-inch-wide rabbet along each long edge of a 2×8 piece of 11/2-inch-thick extruded polystyrene board. When two sheets are butted together, the rabbets form a 3-inch-wide vertical channel. When used to insulate an entire wall, the rabbets form a series of 2-foot on-center channels that are just big enough for 1×3 furring strips, which can then be fastened through the insulation and into the wall with Tapcontype screws. The furring strips hold the insulation in place and act as a screw base for drywall. Wallmate has an R-value of R-7.5 and