Garage Door Insulation R-Value Explained
Garage Door Science
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Model your door's heat loss
Drag the R-value slider. Watch the heat-flow visualization shift. See the dollar impact on your garage temperature and utility bill.
Transcript
Our value is the resistance rating, how well your garage door blocks heat transfer, but the number on the brochure doesn't tell the whole story. A non-insulated steel door runs R0 to R2. A polystyrene backed door about R4 to R7. Polyurethane foam injected doors start at R10 and can reach R18 or higher. The difference isn't just the number, it's how the insulation is bonded to the steel. Here's what most people miss. Our value tests are done on a flat panel in a lab. A garage door has edges, seams, and a perimeter seal that leaks more heat than the center panel ever will. A door rated R16 with a bad seal performs worse than an R8 door with tight weather stripping. Check the seal first. We built a full breakdown of insulation types, realorld performance, and cost per rpoint at garagedoscience.com. If you're deciding between a new door and upgrading what you have, start
