I am replacing dining room floor, from the floor joists up. I have placed 6 mil plastic on the ground. I would like to recycle about 600 sq. Ft of 3/4” x 2-1/2” oak and maple hardwood flooring as the subfloor, since that is what I have available. I will be placing 30# felt over this subfloor, then either porcelain tile (12x12), using 1/4” cement board, or hardwood. Thoughts on using the recycled hardwood as a subfloor. Thanks, David.