How to calculate Floor Insulation Effective R-Value
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I have a 2×12 floor system with R-19 supported by spring wires every three feet or so. The insulation is 5″ from being in substancial contact with the floor. What is the effective R-value and what publication can I point to for substantiation.
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Replies
Tyson,
Since you don't have an air barrier on the underside of your fiberglass batts, the effective R-value of your insulation is (I'm just guessing here) somewhere between R-0 and R-a very low number.
If you want to point to a publication, how about Fine Homebuilding? Here's an article, How to Insulate a Cold Floor, that states, "If the batts aren’t thick enough to fill the joist bays, they may fall away from the subfloor and rest on the OSB below. At that point, the floor assembly has an R-value of 0."