Teardrops n Tiny Travel Trailers

I'm trying to think ahead for one thing what thickness ply to use on the top of the tear.When you come to the hatch, you put the ribs in place and there will be one on each sidewall glued into place on the wall (these two not part of the hatch) for strength. My question is when you skin the hatch does the ply just hang out over (in the air) the stationary ribs? What if you use thin ply, how do you attach molding to the topside? Isn't there a chance of it breaking off at some point?
Thanks Keith

keith, it i understand you right you have two ribs glued to the outside and your question is will the plywood and skin hang over to the outside edge of the stiffners. i would say yes. mine has that lip too most of them do. i got a sheet of of plywood from lowes that was just under a 1/4" and it was exterior grade. i put two sheets on mine. after the metal was on i trimmed the edge with alum. channel . worked out great. i don't believe you will have a problem with the edge breaking off. if you look at my album you wiil see what i did.

Mine overhangs, it is 5.2mm (3/16) ply with Filon then an aluminuim trim. It seems plenty strong.