R-value measures how well insulation resists heat flow, and a higher number resists more. For a garage door the number covers one section, not the whole door, so DASMA prefers a tested U-factor, where lower is better. How much you need depends on whether you heat or cool the garage. An insulated steel door costs more, and the price is confirmed after we see your door.
What is R-value?
The U.S. Department of Energy describes R-value as a measure of a material's resistance to heat flow. A higher R-value means the material is better at slowing heat down, which is why it is used to compare insulation.
On a garage door, R-value describes the foam or other core inside a panel. It does not describe the track, the joints between sections or the seals.
Is R-value the number to shop by?
Not by itself. DASMA explains that a garage door has two different measures. R-value is calculated for a door section only. U-factor is tested on the complete installed door, including joints, stiles, thermal breaks and weather seals. DASMA says the two are not comparable, and that they are not reciprocals of each other for garage doors.
DASMA also says the section R-value method should not be used for a whole garage door. When you can, ask for the tested U-factor, where a lower number means less heat gets through. Its test standard is ANSI/DASMA 105.
| Measure | What it covers | How it is found | Better is |
|---|---|---|---|
| R-value | One door section, insulation only | Calculated | Higher |
| U-factor | The whole installed door | Lab tested | Lower |
Source: DASMA Technical Data Sheet 163.
Do I need an insulated garage door?
It depends on how you use the space. If the garage is an open storage area, insulation does little for you. If the garage is attached, shares a wall with rooms you heat or cool, or you use it as a workshop or gym, the door is a large surface worth upgrading.
The Department of Energy also points out that gaps between a conditioned part of the home and an unfinished garage can be sealed with caulk or low-expansion foam. Sealing those gaps is often a cheaper first step than a new door.
How much does an insulated garage door cost?
These are our approved starting ranges for a 16x7 steel door. The final price is confirmed after we see the door.
- Steel door, non-insulated: $1,400 to $2,400
- Insulated steel door, short panel: $1,800 to $3,400
- Insulated steel door, long panel: $1,800 to $3,600
Size, windows, color and hardware change the price. See new garage doors for the full range.
Quick answers
Do I need an insulated garage door?
It helps most when the garage is attached or shares a wall with rooms you heat or cool, or when you use the garage as a workshop. For open storage, the benefit is smaller.
How much does an insulated garage door cost?
Our approved range for an insulated steel door, 16x7, is $1,800 to $3,400 for a short panel and $1,800 to $3,600 for a long panel. A non-insulated steel door is $1,400 to $2,400. The final price is confirmed after we see the door.
Is a higher R-value always better?
A higher R-value means the insulation resists heat flow more, but the figure covers a door section only. A tested U-factor describes the whole door, and a lower U-factor is better.
Can I insulate the door I already have?
Some doors can take add-on insulation kits, but a heavier door can throw the springs out of balance. Have a technician check the balance first and do not adjust the springs yourself.
How much R-value is enough?
There is no single number we can give you for all of Texas. The right choice depends on whether the garage is conditioned, how much of the door is glass, and what you pay for the upgrade. We found no manufacturer or federal source that sets one R-value for garage doors, so we do not name one.
Compare doors on the same basis. Ask for the tested U-factor if the maker publishes it, or the same R-value method from each maker, and ask what the number covers.
Questions to ask a seller
- Is this figure a tested U-factor or a calculated section R-value?
- Does the number include the joints and the weather seals?
- Does the door come with a bottom seal? See bottom seal replacement if yours is worn.
- How does the insulated version change the price for my door size?
Who to call
Emil Garage Doors repairs garage doors, springs, cables and openers and installs new doors in Texas, including Temple, College Station and Tyler. Call or send your door size and a photo of the garage, and we will quote an insulated door next to a non-insulated one so you can compare.
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