Hi all, Quick Q regarding the flooring for a garage conversion. The garage has a concrete floor, im planning on insulating the floor, walls and roof, however im curious around the requirement for floor joists. i will be laying a DPM down ontop of the concrete, my Q is whether i should just put Celotex butted and taped together on top of this, or should i create floor joists and lay the celotex between them? I will be chipboarding and then laminating on top of this, but just curious on peoples opinions on the requirements of floor joists? my thoughts are because i will chipboard i will need the joists, but open to suggestions...?