Bill writes from Lowell, Michigan: "I am building a storage shed and want to insulate the floor. I was thinking of putting down plywood 7/16" and then laying down foam board and then another layer of plywood 7/16". The foam board is 1" thick. Is this a good idea or not?"

Answer: The insulating approach you describe sounds like a good idea if the shed is going to be conditioned (heated or cooled). One additional step that can be taken is to lay sleepers (2 x 4s put down flat, for example) between the FOAMULAR® insulation boards to allow you to attach the final layer of plywood.