[schamp]

I went 40x60 all steel. Either 5 or 6 inches of concrete and 16 foot ceiling with 2 16 foot roll up doors. You have to insulate a metal building I am told or it will rain (condensation, drips) inside. I work with a large power company that when we build a new power plant they put up a large metal building. No insulation. I kept telling them to insulate. They didn't. Cost like hell to insulate after roof is on. I love mine. I don't have to worry about it rotting. It is tough to heat with the 16 foot ceiling but had to have it for my scenicruiser/camper. Good luck.