I'm putting in a new Pleasant hearth 2200 wood stove and I need some advice on the clearance behind the stove. The specs say It needs 16 inches to combustibles behind it. I am planning on using Micore 300 over ½" drywall (that covers 2x4 wood studs). Then ½" durock over the Micore, and finally a tile that has yet to be decided on. So my question is with this combination of non-combustibles, how close can I set the stove to the wall. I'm trying to use the existing chimney in the roof and if I can push my stove back far enough, I will avoid having to put elbows in my stovepipe. Thanks.