Closed-cell insulation
steelbook
| Posted in General Questions on
We are putting close cell insulation in an all metal shop. 1800 sq ft.
What should we watch for ? How thick should it be? We’re in Alabama and it goes get pretty warm. Building has no shade .
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Replies
Steel,
Assuming that this building is subject to building codes, you should check with your local code authority. Most of Alabama is in Climate Zone 3, although the southern part of the state is in Climate Zone 2.
In Climate Zone 3, the minimum R-value for roofs is R-38 (about 6 inches of closed-cell spray foam), while the minimum R-value for walls is R-20 (a little more than 3 inches of closed-cell spray foam).
Ordinary closed cell spray foam has an unreasonably high, outsized global warming impact. Fortunately, you can now specify "HFO" blown foam to avoid this impact.
Is it just the roofing & wall cladding that is metal, or are all the structural elements metal too?
If it has steel studs thermally bridging the closed cell foam any amount or type of closed cell foam is a waste.