Subject ICF house under construction near Jax Florida has a flat roof of 3" of poured concrete held up by Hambro metal joists whose top element is embedded in the concrete.
We'll spray 3-5" (haven't decide on precise thickness yet) of closed cell spray foam on the bottom of the concrete roof...
My county rehabbed a section of an old bridge to serve as a fishing pier. It was done several years ago by public works (not a contractor) under a cloud of scandal concerning illegal dumping, etc.
At any rate what they have is 3x8 nominal (2.5 x 7.25 actual) joists on 24" centers spanning...
I'm having a two story ICF house built into the side of a hill near Jacksonville, FL. It will have a drive out basement. Geo engineer cored and tested soil and determined allowed bearing of 2500 pcf on a conventional shallow spread footer. Soil is mostly sandy but with some clay layers...
