An insulated garage door has foam between two steel skins, so less heat passes through the door into the garage. A manufacturer says plain steel doors get hot in summer, and that R-12 or higher gives the most benefit for an attached garage in an extreme climate. If the garage is attached or used as a room, insulation is worth pricing.
Why the door matters in a hot garage
A garage door is the largest moving wall of your house, and on a sunny day it faces the heat for hours. A plain single-layer steel door passes that heat straight through. Clopay, a door manufacturer, says non-insulated doors get hot in summer and cold in winter in areas with extreme temperatures, and that an uninsulated attached garage can raise heating and cooling costs because the garage sits next to your living space.
That is the manufacturer's view, not an independent test, so treat the savings talk with care. The page gives no payback figure. What it does say plainly is that a door with foam in it slows heat flow, and that mild climates may not need it.
What an insulated door is
An insulated door is built from steel skins with a foam core, usually polystyrene or polyurethane. Clopay lists R-6 to R-9 for standard polystyrene doors and R-6.3 to R-20.4 across its polyurethane models, and says a plain single-layer door is near R-0. Steel facings add almost nothing, so the foam does the work.
Insulated doors are also heavier. Clopay notes they may need a stronger opener and may wear it faster, so the springs and opener should be matched to the door you buy. See new garage doors for the options we install.
What R-value does and does not tell you
DASMA, the garage door trade association, explains that R-value is a calculation for one door section. The tested U-factor covers the whole installed door, including joints, stiles, thermal breaks and weather seals, and DASMA says the two numbers cannot be compared. It adds that U-factor gives the highest confidence when you compare complete doors.
In plain words: a high R-value on a brochure is a good sign, but gaps at the joints and a worn seal can undo part of it. Ask for the U-factor when the maker publishes one, and look at the seals as well as the foam.
Insulated or plain steel
A plain steel door can be enough when
- The garage is detached or only stores bins
- You rarely spend time in it
- The budget is tight and the door is not the heat problem
- Your garage wall to the house is already well insulated
An insulated door is worth pricing when
- The garage is attached to the house
- You work, exercise or park a second fridge in it
- The garage gets very hot before you open the door
- You want a quieter, more dent-resistant door
Clopay also says insulated doors resist dents better than single-layer steel and run quieter. Its own test measured 96 decibels for a polystyrene door and 80 for a polyurethane model, which is the maker's figure, not an independent one.
What it costs
Our approved ranges for a 16x7 door, installed, are $1,400 to $2,400 for non-insulated steel, $1,800 to $3,400 for an insulated short-panel steel door and $1,800 to $3,600 for an insulated long-panel door. Windows, color and size change the final number, and we confirm it after we see the opening.
A quote should name the door model, the insulation type, the R-value or U-factor the maker publishes, the seals, the springs and the opener work if any. For the full set of door prices see new garage door cost in Arizona.
Other ways to cut garage heat
- Check the bottom seal and the side stops for gaps; DASMA lists weather seals as parts that resist heat flow.
- Replace a cracked or flattened seal before you replace the door.
- Keep the door closed when you can; every opening lets in the hot air.
- Insulate the wall between the garage and the house if it is bare.
Clopay says retrofit foam kits perform worse than factory-insulated doors, so a kit is a stop-gap, not a match for a new door.
Who to call
Emil Garage Doors repairs garage doors, springs, cables and openers and installs new doors in Arizona, including Tucson, Marana and Oro Valley. Call or send your details and we will tell you whether your door needs more than a new seal. See garage door repair if the door is working but worn.
Questions people ask
Do I need an insulated garage door in Arizona?
It depends on the garage. If it is attached, or you spend time in it, insulation is worth pricing. For a detached storage garage, a plain steel door can be enough.
How much does an insulated garage door cost?
Our approved ranges for a 16x7 door, installed, are $1,800 to $3,400 for an insulated short-panel steel door and $1,800 to $3,600 for a long-panel door. We confirm the final price after we see the opening.
Is a higher R-value always worth it?
Not by itself. DASMA says R-value covers one section and U-factor covers the whole door, so compare U-factors when they are published and check the seals.
Can a heavier insulated door strain my opener?
Clopay says insulated doors are heavier and may need a stronger opener. Have the springs and opener matched to the door at installation.