My attic only has r11 or r13 insulation. It has some plywood layed down for storage. I was wonderin if i could tear up the plywood and put 2x4s or 2x6 running 90 degrees to the celing joists then adding more insulation and plywood so i can keep my storage space. Will this work? Or is there a better way of adding insulation and and keeping my storage space.