I agree that a built up roof is the way to avoid the bridging. However, homeowner intends to be able to use the roof as an upper deck - it will have a walking surface similar to poolside Cooldeck.
I did some back-of-envelope calculations based on conductivity of steel, expected cross sectional...
Fortunately the % of area works out to about 0.5% of ceiling area. I agree that 5% would cause a significant heat transfer.
My load software doesn't provide for a bridging percentage. I like the idea of calculating the effective R value but would need to calculate the conductivity...
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...
Thanks for the comments so far.
Pier is strictly for walking and is not configured for boat docking other than at one spot too shallow for all but one or two small recreational vessels.
Pier has a barricade blocking wheeled traffic, although I'm sure the county gets out on it with light weight...
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...
Thank you both.
My primary objection to the corrugated stuff is the high probability that any snaking or auguring to clear it would damage it.
I agree that the role of gravel is to store, slow, and conduct water, but not to filter it.
Polyguard waterproofing will extend down the wall below...
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...
