Somewhere on here is a thread discussing that very subject, I just can't find it. If I remember correctly, the consenus was 3/4" plywood for substrate. I suppose you could get away without it using alum. as many converted commercial trailers do not have any. Since I am mounting the A/C,vents and TV satelitte on the roof,I felt 3/4" was the way to go. It also adds some insulation value. Just my opinion. MMM
|