Teardrops n Tiny Travel Trailers

I am about ready to close up the front end. I am doing angled as opposed to curved and was thinking how much support do I need as far as a spar goes.

The plan is to put 1/2 inch baltic birch plywood with the lower portion having black aluminum diamond plaing and a 1/2 inch upper with just paint.

its the backside i am questioning, i could do a 2X2 spar at the angle. or do I just do a 3/4 inch? then skin with the cherry veneer plywood.

Roof is still 3/4 inch to just give it some strength. [/url]