What Is A Good R-Value For A Garage Door?


If you’ve shopped for a new garage door recently, you’ve likely heard the term “R-value” thrown around a lot.

Unless you’ve done a lot of home renovations, you may not be familiar with the term or know why it’s relevant to your garage.  

What is a good R-Value for a garage door? Detached garages need a lower overall R-value (between 0 and R-6). Attached but not actively heated or cooled garages should have a garage door with an R-value between R-6 and R-9. Actively cooled or heated garages should have a garage door with an R-value of R-13 or higher to save on energy costs.

In general, a higher R-value means better insulation, but there’s more to it than that.

Let’s dig in a little further.

Why Is Insulation Important for Garage Doors?

Besides being literally a giant hole in the side of your house, garage doors are typically made of thin metal materials which allow heat to transfer in and out easily. Usually those materials are either steel or fiberglass.

Fiberglass doors are lighter and more efficient than steel, but less durable. The vast majority of garage doors are built using steel.

Steel doors conduct heat very well. This means that in summer your garage door becomes very hot and in the winter, it becomes very cold.

That then causes the air inside your garage to change temperature as well.  

The point I’m trying to make is that garage doors are horribly inefficient when it comes to regulating the temperature in your garage.

R-Values: The basics

So that we’re all on the same page, let me go over some basics about insulation and R-values. If you want more details, I do into the subject in a lot more depth in my article on garage door insulation.

Insulation is rated on a scale called an R-Value.

When the R value of a material is low, it conducts heat very easily. When a material’s R value is high, it does not conduct heat well, making it a good insulator.

The US Dept of Energy considers “High R-Value walls” to be R-40 or above for Zero Energy Ready. Currently, there are no Energy Star rated garage doors. (source)

Let me give you an example.

If you leave an all-metal spoon in a pot of boiling soup, it will gradually heat up to the temperature of the soup. If you then grab the ladle, you’re going to burn your hand.

This is because metal conducts heat well and transfers that heat quickly. We would say this has a relatively low R-value.

By contrast, a spoon with a rubber handle (insulation) wouldn’t get as hot, so it would have a comparatively high R-value.

R-Values: More is better (to a point)

16 is twice as much as 8, right?

Not if you’re talking about R-Values.

Insulation R-values follow the law of diminishing returns, as you can see from this chart from Amarr garage doors.

source: amarr.com

Manufacturers naturally want you to think that an R-16 garage door is twice as effective as an R-8 garage door because that’s the way our brains work.

And they’re going to price their garage door to take advantage of it.

The lesson from this is to be careful when you’re shopping for insulated garage doors.

You might think you’re buying a door that’s twice as efficient, when you’re really only getting a slight improvement in efficiency.

Recommended R-Values for Garage Doors

Generally speaking, not everyone needs a garage door with a really high R-Value. So choosing a good R-value for a garage door really depends on what kind of garage you have and how much time you spend in it.

Here is the breakdown of recommended R values: 

  • Non-insulated to R-6: I recommend this range non-insulated and detached garages where you don’t spend a lot of time working in. If the walls of your garage aren’t insulated, then it really doesn’t make sense to have an insulated garage door.
  • R-6 to R-9: I recommend this range for attached garages that are not conditioned (heated or cooled, depending on where you live). The doors are reasonably inexpensive, but still provide enough insulation to prevent cold damage to any items stored in the garage.
  • R-9 to R-13: This is the recommended range for conditioned (heated or cooled) garages. You want the R-Value to be as high as possible so the air you’re heating or cooling stays inside where you want it.  
  • R-13 and up: If you’re trying to create a Net Zero home or have converted your garage into a living space, this is where you want to be looking. You’re going to pay a premium for these garage doors, but you’ll also save a lot on energy costs over the life of the garage door.  

Beyond these general recommendations, it’s a good idea to get the highest R-value that’s possible if you want to be energy efficient. However, the price of a garage door goes up significantly due to the increased cost of materials. 

Insulated Garage Doors From Major US Manufacturers

I struggled to make sense of all the different options when I was doing my research, looking for a new insulated garage door for my home.

So to make things easier, I compiled a list of the insulated garage doors from some of the major manufacturers in the United States.

That way I could look at everything all at once and try to narrow my options down to five or six garage doors, instead of thirty. Hopefully this will help make things a bit easier for you too.

ManufacturerModelMaterialInsulation TypeR-Value
AmarrClassica CL3000SteelPolystyreneR-13.3
AmarrDesigner’s Choice DC3200*SteelPolyuretheneR-13.3
AmarrOlympus OL3200SteelPolyuretheneR-13.3
AmarrDesigner’s Choice DC3138*SteelPolyuretheneR-14.4
CloplayClassic Premium 4000 seriesSteelPolystyreneR-6.5 or R-9
CloplayClassic Premium 9000 seriesSteelPolyuretheneR-13.3 or R-18
CloplayClassic ValueSteelPolystyreneR-6.3
CloplayCanyon Ridge (full plank)Steel + CompositePolyuretheneR-20.4
CloplayCanyon Ridge (plank w. aluminum trim)Steel + CompositePolyuretheneR-18.3
CloplayCanyon Ridge (Glass windows)Steel + CompositePolyuretheneR-6.3
CloplayModern Steel 4000 SeriesSteelPolystyreneR-6.5 or R-9
CloplayModern Steel 9000 SeriesSteelPolyuretheneR-13 or R-18
Overhead DoorThermacore 200 SeriesSteelPolyuretheneR-9.3
Overhead DoorThermacore 100 SeriesSteelPolyuretheneR-12.7
Overhead DoorThermacore 400 SeriesSteelPolyuretheneR-17.5
Overhead DoorTraditional Steel DoorsSteelPolystyreneR-7.4
Overhead DoorTraditional Steel DoorsSteelPolystyreneR-10
RaynorCountry ManorSteelPolyuretheneR-18.3
RaynorEden CoastSteelPolyuretheneR-18.3
Wayne-DaltonModel 8100 SteelPolystyreneR-3.7
Wayne-DaltonModel 8200SteelPolystyreneR-7.4
Wayne-DaltonModel 9800FiberglassPolyuretheneR-7.6
Wayne-DaltonModel 9100SteelPolyuretheneR-9
Wayne-DaltonModel 9605SteelPolyuretheneR-10
Wayne-DaltonModel 8300SteelPolyuretheneR-12.1
Wayne-DaltonModel 8500SteelPolyuretheneR-16.2

Conclusion

Investing in an insulated garage door isn’t the only way you can make your garage more comfortable. Here are two often overlooked ways to fix up your garage: 

  • Adding insulation to the walls. This was one of my first big garage projects and it’s made a huge impact so far. If you want to see how I did it, check out my series of articles where I insulate my garage walls before adding drywall.   
  • Adding insulation to the ceiling. This is a step that many people don’t consider, but the ceiling is one of the most important places other than the garage door to provide insulation, as heat rises and is most easily lost through badly insulated attics.
  • Add a garage door insulation kit: If you don’t want to spring for a whole new insulated garage door, installing a garage door insulation kit from Matador is a cost-effective alternative. You can see how I did it in that step-by-step guide linked here.

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