My Oslo is sitting in front of my existing fireplace. If you measure from the rear side corner of the stove diagonally to the face of the fireplace which is covered with sheetrock I only have about 10 inches. If I put tile over the sheetrock will that be code as far as a non combustible surface ? Also will using regular tile adhesive under the tile constitute a fire hazard ? I can't really use thinset mortar over sheetrock.