Insulating Junior Beam Construction

Old 04-05-18, 08:10 AM
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Insulating Junior Beam Construction

I live in an 82 year old house with a basement. The first floor is made using junior beam construction -- steel i-beams set about 30 inches OC with poured concrete about 4 inches thick. The i-beams are about 10 inches in height which creates a stud bay about 6 inches deep under the floor (on the basement side).

Part of the floor is over an unconditioned integral garage. The room above the garage is conditioned. I live in a zone 5 climate. I'd like to use Roxul rockwool batts which have a 5 1/2" thick batt.

Should I install a vapor barrior on the cement side of batts?

I'd appreciate any other advice on the installation as well.

Last edited by J-Beam; 04-05-18 at 08:14 AM. Reason: adding detail
Old 04-05-18, 10:05 AM
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Nope but air sealing over a garage is critical.

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