Garage Door R-Value – FAQs

If you are shopping for a new garage door, you have probably seen R-value attached to different models. You could be wondering what that number is and how important it is. We can say that it is significant and you can read on to find out answers to the most common questions about R-value.

 What does R-value stand for?

R in the expression means resistance. The value measures how resistant the door is to heat. When there is a difference in the inside and outside temperature – for example, it’s warm inside and cold outside, the warm air from the inside wants to get out and even up the temperature.

Door is insulated to prevent that from happening. R-value attached to a door represents how good the materials are in stopping warm air seep out. When it comes to garage doors, the higher the value the better the door is at stopping heat flow.

Is R-value connected to the type of insulation material?

Some materials are better insulators than others. Styrofoam (polystyrene) and spray foam (polyurethane) are the most common insulation materials in garage doors. They are quite alike, but the function differently and therefore, their insulation capacities are not the same.

Styrofoam is placed in garage doors in panels. This prevents it from closing off airways completely, because the panels are never exactly the perfect fit for the door. Spray foam, on the other hand, is sprayed on the door, after which it expands and sticks to the surface. Because it sticks, spray foam also doubles as noise insulation, making the garage quieter. As you can imagine, a garage door insulated with spray foam has a higher R-value.

How do they measure R-value?

R-value of garage door is the sum of materials used in the construction. If you know the make-up of a door, you can check the R-value of materials online and add them up. The end result should be the ballpark of R-value.

Why is R-value important for customers?

R-value of a door you are considering buying will indicate how good the door will be at insulating your garage and home. Since the garage door is usually the biggest opening in a home, it’s an important point in airway sealing.

If you have to heat your garage the whole winter to keep it warm, that can put a dent in your wallet. Heat loss in winter or heat gain in summer burdens your electricity bills and your home budget. You should consider getting a door with a higher R-value if this is your situation.

But, if your garage isn’t used much in winter or it’s detached from the house, you could consider getting a door with a lower R=value.

What R-value is desirable for a new garage door?

The rule of thumb is the higher, the better. However, there are other factors as well. R-value and the quality of construction should be your primary beacons.

Look how well done the bottom seal is, together with weather stripping, and sealing panel joints.