R-value is a rating of thermal efficiency for all kinds of building and construction, from windows and walls to garage doors. An R-value tells you how well a barrier slows the transmission/flow of heat.
R-value is equal to the temperature difference between a warmer surface and colder surface of a barrier divided by the heat flow through the barrier.
Typical garage doors have an R-value of between 0 – 20.
A higher R-value means greater thermal efficiency. An R-value of 0 means no efficiency at all.
Here’s a helpful chart from manufacturers Amarr which gives an indication of the efficiency of values R-8 – R-32. Please note however you will not likely find a garage door with an R-value higher than 20.
What R-Value Should You Choose?
This can depend on a range of factors: whether your garage is attached, detached and insulated or not. Generally, R-values of 6-8 are not bad and work well for many homes.
- For attached and insulated garage doors, an R-value of 12+ is recommended.
- For detached and insulated garage doors, an R-value of 10+ is recommended.
- For unheated and uninsulated garage doors, an R-value with a low or no R-value is sufficient.
What Insulation Offers the Best R-Values?
There are two types of insulation commonly used in garage doors: polystyrene and polyurethane, both have a wide range of applications in all kinds of thermal insulation, not least garage doors.
According to garage door manufacturer Raynor, the R-values for their polystyrene and polyurethane insulated doors are:
Polyurethane Insulation – 12.0 – 18.0
Polystyrene Insulation – 5.0 – 10.25
This gives you an indication, though other manufacturers may be different. If you want the best insulation from your garage door, look for polyurethane.
As is true with many of the top manufacturers these days, this is how Raynor describes their polyurethane insulation:
“Polyurethane insulation is blown between the garage door’s steel skins and expands to fill 100% of the door’s interior space.”
and for polystyrene:
“Rigid, lightweight expanded polystyrene insulation provides excellent protection against noise and weather.”
R-Values of Some Popular Garage Doors
- American Legends by Fimbel ADS (aluminum/steel) – 13.12
- Euro Door by Fimbel ADS (wood core & polystyrene) – 8.12
- Roaring 20s (wood core & polystyrene) – 9.5
Overhead Door Company
- Impression Fiberglass Collection (aluminum & polyurethane) – 7.6
- Carriage House Collection (steel & polyurethane) – 10
- Thermacore® Insulated Door (steel & polyurethane) – 9.31, 12.76, 17.5 depending on model
- Durafirm Collection (vinyl, steel & polyurethane) – 11.75
- Aspen™ AP200 (steel & NeuFoam™ Polyurethane) – 18
- Aspen™ AP138 (steel & NeuFoam™ Polyurethane) – 13
Do you have questions about garage door insulation, R-values and selecting a garage door for your home or business in Fairfield/New Haven County Connecticut? Speak to our garage door specialists, call: (203) 800-5606