I'll have to measure, I can't remember. I think they are 2x12s, could be 2x10s. we then put a layer of 3/4" plywood, roofing felt, 1/2" plywood, roofing felt and another layer of 3/4" plywood on top. It was attached to the wall with lag bolts and then screwed and glued together.Jim Mcc said:Yikes !! Those look like 2 X 12's.