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How to insulate a steel joist floor?

user-231615 | Posted in Energy Efficiency and Durability on

I have 3000 feet of 12 inch, galvanized 10 gauge steel joists. I plan to use them in my otherwise wood framed house. What is the best way to insulate? I am considering 3″ foam either on top on under joists. I want to avoid thermal bridging.

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  1. Michael Chandler | | #1

    I'd recommend an insulated, sealed crawl. Which doesn't answer your question I know, and I'm sorry but there is really no easy way to insulate steel joists so the solution is to re-locate the thermal envelope to the perimeter.

    The advantage is that you bring your infrastructure into the envelope and use less insulation in that the crawlspace walls are generally less SF than the building floor. will get you started.

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