Covering rigid foam insulation in furnace area
We put up some rigid foam insulation on an exterior wall behind our furnace and gas water heater. We know we have to cover the rigid foam because it's flammable and emits toxic fumes, but there isn't enough room down there to build a stud wall. We're thinking now that we should have used Wallmate with the built-in furring strips. So, my question is: can we just glue furring strips to the rigid foam and screw the drywall into them (without having to use Tapcon screws to go right through into the concrete, because we haven't had a lot of success with those)? It's an area that's only about eight feet wide by about seven feet tall -- the rest of the furnace room will be properly drywalled.