I used .032 thick al. 6061 T6 for a flooring material because that is what I had available. After 35 hours of engine run-up, taxi tests, crow hops and 10 touch and go with 20 landings I have found that the bottom diagonal cross member has caused abrasions to the aluminum. I have applied a silicon bath tub sealer to the top of the diagonal cross member to prevent the erosion of the aluminum. If I had used .016 it might have worn though.