R-Value (Insulation)

A measure of insulation's resistance to heat flow — higher R-value means better insulation.

Code-minimum R-values vary by climate zone — typically R-30 to R-49 in attics, R-13 to R-21 in walls. Higher is better but not free; doubling R-value cuts heat flow in half, doesn't double comfort.

Air sealing usually matters more than incremental R-value past a point — a leaky R-49 attic loses more heat than a tight R-30 one.

Related

• Building Envelope — The physical separator between the conditioned interior and the unconditioned exterior — walls, roof, foundation, windows, doors.
• Compare contractor CRMs — FieldKrew against Jobber, Housecall Pro and ServiceTitan
• Square (Roofing) — A unit of roof measurement equal to 100 square feet — the standard way roofers measure, quote, and order materials.
• Pitch (Roofing) — The slope of a roof, expressed as rise over run — e.g. 6:12 means 6 inches of rise per 12 inches of horizontal run.
• Waste Factor — The percentage of extra material added to an order to account for cuts, valleys, hips, and mistakes during install.
• GFCI (Ground Fault Circuit Interrupter) — An outlet or breaker that shuts off power within milliseconds when it detects a ground fault — required in wet areas by code.