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Does A Garage Need Insulation? (Pros, Cons, How-Tos, and More)

Many garages lack wall and ceiling insulation but adding insulation to a garage can significantly reduce energy bills and make garage space more comfortable.

Garage area with white paint door and blue trim windows.

Garages help keep vehicles safer by deterring thieves. Their fully enclosed and secured space also keeps the weather from adversely affecting your vehicle. Insulation keeps a garage space warmer and reduces the cost of energy bills.

Older garages may not have received insulation when initially built but they should include insulation in the ceilings and walls. Attached garages need insulation more than detached garages because their temperature affects the temperature of the home and its use of heat and air conditioning.

If your home’s garage doesn’t already include insulation or its older insulation needs an update to a higher “R” value, read on to learn how to add it. Properly insulating or air sealing a garage keeps your vehicles healthier and makes the space more versatile by making it warmer in winter and cooler in summer. A garage insulation project won’t cost much and a DIY garage insulation project costs just the materials but can save you immensely on energy bills in the future.

Is A Garage Insulated?

Some builders leave certain areas of a home unfinished to save the homeowner money. Initially, the attic, basement, and garage may not receive insulation or wallboard. This means these areas experience a greater susceptibility to the weather. Drafts easily enter these rooms and they get colder in winter.

You can easily tell if your walls already contain garage insulation. In most garages without insulation, no wallboard covers the wall studs (the two-by-fours) that comprise the framing of the room. Typically, after installing insulation, a contractor covers the batting or blown-in insulation with wallboard, also called Hardy board or drywall, creating a solid wall. If you see the two-by-fours of your framing, your home’s garage does not have complete insulation.

building of a detached garage without  insulation
Building of a detached garage with a visible frame for insulation.

This still-under-construction detached garage doesn’t yet include garage insulation or wallboard. You can see through the crevices between the exterior boards and view the wall studs. Unblocked by insulation, these crevices would allow continuous air to enter, driving up the temps in summer and creating cold in winter. Left this way, the garage robs you of any energy efficient way to heat and cool it.

How is A Garage Door Insulated

Garages typically feature a folding or swing-up or open door for moving the vehicle in and out of the building. They also feature an entry door to either the yard or the home.

Most garage doors use either metal construction that does not contain insulation or solid core garage doors that use panels with no open space inside. These solid garage doors offer the best choice over metal doors with a single, double, or even triple layer of metal. You can purchase an insulated garage door, but they cost between $5,000 to $15,000.

In a detached garage, using a solid core entry door affords you the best option for the door used to enter and exit the building. In an attached garage, you have leeway, since the entry door typically opens into the home’s mudroom or kitchen. You can use either a hollow core door or a solid core door.

Installation of solid-core garage door
Installation of solid-core garage door with a white and wooden accent design

Garage doors typically don’t feature insulation like a wall does. Choose a solid-core garage door, like the one pictured, for the best results.

Do You Need to Insulate a Detached Garage?

For the health of your vehicle, any garage you park it in should feature insulation. Your property’s detached garage may not currently feature insulation, especially if you own an older home. Homes constructed before the 1950s typically used a detached garage building. Since people simply parked and hustled inside their homes, builders didn’t focus on finishing out the garage or adding insulation.

Today, garages undergo multiple uses. Besides functioning as car parks, they also provide storage space, an area for a home gym, a home office, or extra living space. Using your garage for anything besides just parking a vehicle means adding insulation. When you insulate garage walls, you provide greater comfort in the room and reduce energy bills by blocking cold air.

An empty one-car detached garage
An empty one-car detached garage in white interior paint.

Older detached garages and those erected from metal kits may not initially contain insulation. Adding it to the detached garage can increase its utility and improve the protection it provides your car.

Should You Insulate Your Garage Ceiling?

In an attached garage, your home’s garage ceiling probably already has insulation. That’s because your attic spans the entirety of the home’s ceiling. If you traverse up the probably dusty, unused stairs, you’ll likely discover one large open space upstairs. Most attics don’t get divided with walls unless the homeowner finishes them out as a spare room or living space.

If the rest of the house features insulation in the ceiling, your garage ceiling does, too. That doesn’t mean you shouldn’t contact a roofer or insulation expert for a free inspection. Those complimentary inspections offer you a way to determine what areas feature insulation and what “R” value from an expert.

Your garage ceiling should feature insulation, just as the rest of your home should. Insulation helps block drafts, so windy days can’t drive your utility bills sky-high. Without fiberglass or foam insulation, your home can’t protect itself from the elements properly.

Garage ceilings on detached garages typically feature no insulation. You can easily add loose fill insulation to alleviate the problem of a cold garage. Wall and ceiling insulation reduces the need to use a space heater to make a space more bearable.

Ceiling panels with light and exposed beams
Ceiling panels with light and exposed wooden beams.

An unfinished ceiling in a detached garage contains no insulation. You can plainly view the ceiling boards that hold the roofing on the opposite side.

A spacious garage with an insulated ceiling in white interior paint.
A spacious garage with an insulated ceiling in white interior paint.

The finished ceiling in this attached garage indicates it likely features an insulated ceiling. Like many homes, the entrance to the attic sits near the door to the interior of the home. This means the attic runs continuously from above the garage and across the rest of the home. If the rest of the home’s ceiling received insulation, the garage did, too.

What is The Average Cost of Insulation for Garage Walls?

According to Bob Vila, the home remodeling expert, depending on the thickness of the material, insulation materials cost between $1 and $5 per square foot. That means a 180-square foot garage could cost less than $200 for insulation materials. The cost of labor for insulation installation ranges from 25 cents to 50 cents per square foot.

The type of insulation matters. Blown-in insulation costs the least, followed by batting/roll insulation, radiant barrier, fiberglass insulation, and finally, spray foam insulation. The latter offers the best return on investment (ROI) though.

Materials for insulation in a separate layer.
Materials for insulation are shown in a separate layer.

The cost of insulating your home’s garage depends on the type of insulation used, its “R” value, and local labor costs.

What Does “R” Value Mean and What “R” Does My Garage Insulation Need?

If your garage does not already feature insulation in its walls, it needs it. Choosing a product with a higher “R” value offers better insulation from the elements.

The term “R” value refers to a material’s ability to insulate the interior from exterior elements and climate activity. These values range from three to eight, expressed on the material itself as:

  • 3 R-value,
  • 4 R-value,
  • 5 R-value,
  • 6 R-value,
  • 7 R-value,
  • 8 R-value.

The higher the number, the better the insulation performs. Two sheets of 4 R-value, laid on top of each other provide the same protection as one sheet of 8 R-value, so if you see low R-value insulation on clearance at a price that would come under a single sheet of 8 R-value, you found a great deal.

Insulation material with visible frames
Insulation material with visible frames installed at the ceiling.

You can combine lower R-value products to increase the insulation in the attic, walls, or garage. This nets you the same results as one high-value insulation product.