tony.latham wrote:I’ve seen somebody on this forum glue the spars to the ceiling first and they pulled it off. Can’t recall who it was.
I did my roof that way, but I didn't have a ledge, per se. Just flat topped walls with no outer skin (since I was doing monolithic epoxy/FG outer skin... i.e. fiberglass wrap). I held my ceiling ply back from the outer edge of my foam walls a little but let the spars... which had the 3/4 inch roundover radius of my roof to wall edge already on them... come out to where the epoxy skin would grab the end grain of the spars, then I infilled between the spars with foam board, packed the gap between ceiling edge, wall face and roof foam with small strips the same foam, and rounded the foam over to match the ends of the spars... no corner trim required. I had to make sure the ends of my spars stayed flush to the walls (as best I could) and didn't worry too much about the ply (... well, I did, but it was less critical than trying to match the spars to the side walls perfectly... just a lot of careful measuring and positioning during glue up). I did have a small variation at the top of the front wall where the ceiling ply met the front wall ply a bit skewed, but I was able to plane the edge of the ceiling to match just as the last bit of bending was taking place and she fell into place on the slat that doubles as the ledger for my key catcher shelf.
My roof arch isn't that tight (something like 520-540 inch radius over the top section or the profile), and at 64 inches wide, with the 5mm Okoume ply being heavier than 1/8 birch, my ceiling panel wanted to sag more than I was comfortable without spars installed. It was nice doing the staining and poly flat on the bench and then having the ceiling finished with very tight "no corner trim required" fit instantly after installation; just a little masking tape to remove and pow, she was done.

BTW, Mr. Lahey (and Breb), your camper is looking fabulous! Keep up the good work!

