I'm floating an aluminum sheet on my flat topped, 8x5 painted plywood roof.
I've perused these forums but I"m still confused on just how to handle the edge sealing and really don't want to make a mistake.
I'm thinking I'll put 4 inch wide eternabond tape around all roof corners extending an inch down (along the walls which are plywood) and 3 inches on the roof.
Then lay down the aluminum sheet so it rests on top of the tape. It will be about 1/4 inch from the edge of the roof on all sides.
Then 1-inch "L" aluminum trim along the edges.
Stainless steel screws through the trim, tape and into the wood, but NOT into the aluminum sheet (so it will float freely).
My questions--
Would it be better to get 2 inch eternabond instead and put it OVER the aluminum instead of under? (2 inches would be needed in that case so the 1 inch trim can then cover it.)
And--in either scenario, I'm assuming caulk (with polyurethane) is still going to be needed--but where should that go? Between the trim and tape? Or between the tape and aluminum? And how permanent is it considering the expansion/contraction of the aluminum float? Won't it break down as the aluminum flexes?