Dick, I need as much support up on the roof because I've got one side of it covered with 2-dozen PV panels and an Apricus system. I'd only go with the polyurethane SIPs if someone were already making an 8-1/4". I wouldn't want to drop from a 10-1/2" EPS to a 6-1/2" polyurethane SIP. I can't help but think that I'd be giving up too much support going to the 6 1/2".


John

John;

What part of the country are you building in?

6" EPS steel sips will easily span 18ft. unless you have a heavy snow load

plus- steel sips can be used with as much as a 4ft, unsuported eave overhang.

and the underside is already a prefinished soffit

I'm building in midcoast Maine, 20 miles from the ocean, USDA Zone 5.


John