Originally Posted by EastCoastCB
Hmmm High quality steel usually rusts faster. I've got cold rolled and hot rolled and the cold rolled rusts immediately.
its made of the same kind 9f steel they make shipping containers out of afaik. it will get a sirface patina of rust, but wont ever really rust through, the patina actuallymprotects rhe underlying layers of steel from rusting.
this is why people that want to bury building structures cheap use shipping containers, bus shells, and train cars. i was surprised at how well it held up, but i digress.
to the op;
fwiw; i use foam strip plus compression for the best water tight seals on my roof, eg; the ac system has nothing more than four bolts and a 1inch thick strip of foam seal all the way around. i made 2x2 wood frame lagged in place for the supports. i used similar for my hatch seals, wish i would have done the same for the openings of the hatches, because it works pretty darn well, 8 might rebuild them someday.