Garage Door System GuideAmarr and Overhead Door are two established steel garage door brands, and both publish detailed specs. This page lays those published numbers next to each other. It does not crown a winner, because the right door depends on your climate, budget, and which model within each line you compare.
How to read this comparison
Brand-level specs are only meaningful when you compare like models. Each brand sells a ladder from single-layer builder doors to premium polyurethane doors, so a premium door from one brand is not comparable to a builder door from the other. Read R-value carefully too: both brands note that they publish a calculated door section R-value alongside tested U-factor, and DASMA says those are measured differently. Treat everything below as manufacturer-published figures for specific product lines, not universal brand claims.
What Amarr publishes
Amarr's Designer's Choice line is built in triple-layer construction with 1-3/8 inch or 2 inch polyurethane insulation and lists R-values of 13.35 or 19.40. Its steel panels are coated in a five-layer paint system with factory colors plus access to over 800 Sherwin-Williams colors through Amarr Color Zone.
Across other lines, Amarr describes its Heritage door as heavy-duty 24-gauge steel with a Lifetime warranty and optional 2-inch polystyrene giving R-values from 6.64 to 9.05, and its Classica line with polystyrene or polyurethane options ranging from 6.64 to 13.35.
What Overhead Door publishes
Overhead Door's Thermacore Collection uses a continuous layer of foamed-in-place, CFC-free polyurethane insulation sandwiched between two layers of corrosion-resistant steel. It publishes U-factor and R-value figures for three models: Model 5720 at a .20 U-factor and 9.31 R-value, Model 5740 at .15 and 12.76, and Model 5760 at .10 and 17.5.
Overhead Door finishes these doors in hot-dipped galvanized steel with two coats of baked-on polyester paint, and publishes a 20-year limited warranty on Model 5720 with a limited lifetime warranty on Models 5740 and 5760.
Where they differ on paper
On published insulated R-value ceilings the two brands are close but stated differently. Amarr lists its Designer's Choice at 19.40 as a calculated door section R-value, while Overhead Door's top Thermacore Model 5760 is published at a .10 U-factor with a 17.5 calculated R-value. Both brands note the distinction between a tested U-factor and a calculated door section R-value.
The brands also frame finishes differently: Amarr publishes a five-layer paint system with Color Zone access to over 800 Sherwin-Williams colors, while Overhead Door publishes hot-dipped galvanized steel with two coats of baked-on polyester paint. Because model tiers and measurement bases differ, matching specific models matters more than the brand name.