TL;DR
R-value is the measure of a material's resistance to conductive heat flow: the higher the number, the better the insulation. It accumulates with thickness—fiberglass batts run about R-3.2 per inch, closed-cell spray foam R-6 to R-7—so an R-49 attic might mean 14 inches of blown fiberglass.
What it means
R-value is the measure of a material's resistance to conductive heat flow: the higher the number, the better the insulation. It accumulates with thickness—fiberglass batts run about R-3.2 per inch, closed-cell spray foam R-6 to R-7—so an R-49 attic might mean 14 inches of blown fiberglass. The IECC prescribes minimums by climate zone and assembly, and the FTC requires the figure on every insulation product label, making it the one number that defines an insulation bid.
Where it sits in the glossary
R-value is part of the Trade jargon group inside the ProFix Directory glossary. Browse every term in this category from the glossary index.
Why Ohio homeowners should know it
This is a term Ohio homeowners encounter when reading contractor quotes, hiring paperwork, or inspection reports. Understanding it well enough to ask one good follow-up question is usually all the protection a homeowner needs.
ProFix Directory keeps definitions short on the index page and saves the longer context — Ohio-specific rules, where the term comes from, and which ProFix tools touch it — for these per-term pages so the term is easy to cite and easy to share.
ProFix tools that touch this term
See also
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