Your ceiling deserves a little love, too
If you want to control the temperature in your garage, insulating the ceiling is a must.
Depending on your home’s construction, you can use cellulose, fiberglass, mineral wool, or spray foam insulation.
In many cases, garage ceiling insulation installation can be a DIY job.
Garage ceiling insulation can turn your garage space from a simple spot to store your car to a comfortable workshop, gym, or office. It can also help make your home more energy efficient. Unfortunately, garages are often uninsulated, which means your little oasis might be the least comfortable room in your house. If you’re puzzled about whether or not insulating the garage ceiling is worth the money and effort, we’ve got you covered.
If you plan to heat or cool your garage, an insulated ceiling is essential to ensure the climate-controlled air doesn't escape through the roof or walls.
Most homeowners opt for batt insulation, which costs between $1.70 and $3 per square foot, putting the total project cost at around $530 for the materials. This is a relatively inexpensive home improvement project, especially since it can make a big difference in your comfort.
An insulated ceiling is especially important if you’ve got a living space above the garage. During the summer, the heat from your garage will seep into that space, potentially making it unlivable or undermining the air conditioning and raising your energy costs. Winters, in turn, will be cold and drafty.
If you’ve already taken steps to improve your garage’s efficiency, like replacing your old garage door, insulating the ceiling is a good final step to ensure all that previous work doesn’t go to waste.
The ceiling can also be the best place to start if you haven’t insulated other sections of the garage, making the single biggest impact of any section of the room in maintaining a consistent temperature.
In addition to making your garage more comfortable and energy-efficient, it can also be a cost-effective way to dampen noise—a crucial bonus for a multi-purpose garage, offering a little distance from any work you do in the space and even from outdoor noise coming through your garage door.
Additionally, the right insulation can prolong the life of your garage roof, preventing drastic temperature changes that can distort wood and drywall.
Finally, it’s a low-cost job with a high ROI, making the project a no-brainer for anyone concerned with boosting the value of their home before a sale.
Like any other insulation job, there are a variety of different materials and methods one might employ on the garage ceiling.
Depending on the climate in your area and the thickness of your ceiling joists, aim for a total R-value between R-13 and R-30.
Fiberglass is the most popular insulation material on the market for garage ceilings and homes in general. It comes in large rolls, precut batts, and as loose-fill, like cellulose. Loose fill fiberglass insulation is only an option if you have finished ceilings, but batts work well for an unfinished garage.
Batts are faced with paper (a requirement in some building codes) that makes installing the insulation a breeze, even for beginner DIYers. Batt or roll insulation are among your best bets if you want to retain access to the attic since they can be lifted and rolled back as needed.
Composed of bits of recycled material, usually paper or denim, cellulose insulation can be packed in by hand or sprayed on when mixed with water. In most cases, it will be the least expensive option—and it can be installed as a DIY job so long as you’ve got at least one additional person to help out—but it can create difficulties if you need to access your attic or any wires or pipes.
Denser than fiberglass, mineral wool is a less common type of insulation, also sold in batts and rolls. Spun from molten rock and strengthened with glass fibers, it’s also less irritating to the human body than other types of insulation—but the material is on the pricier end of the spectrum.
Polyurethane spray foam offers the most robust insulation on the market—combining a high R-value with an airtight seal that stops drafts. It is more expensive than other options, especially in its more rigid closed-cell form best suited to heavy-duty applications like a garage ceiling. And unless you're just insulating a small area, it will likely require professional installation. It’s one of your best options, though, if you’re planning to eventually run any new wiring or piping through the garage ceiling since it is applied along the roofline, leaving some access to the trusses and framing.
Foam board insulation is made of a dense foam core and can also be laminated on either side—though that’s not always the case. This type of insulation is also known as “continuous” or “rigid” insulation. A benefit of foam board insulation is that it does more than prevent heat loss—it can also control vapor and moisture flow and keep the inside of your wall dry.
Depending on the material and method of insulation you choose, as well as the nature of your space, insulating your garage ceiling could be a relatively simple DIY job or something that requires the assistance of a contractor.
On their own, many types of insulation—including fiberglass batts and rolls and blown-in cellulose—allow for accessible DIY installation across a wide range skill levels. Adding them to an existing garage, though, often requires the removal and reinstallation of drywall, so you may need to call in a pro if that’s not a task that you’re comfortable with. Also, keep in mind that the height and sometimes unusual spatial arrangement can add to the difficulty level.
There will be some variation in how you insulate your garage, taking into account the requirements of your space, the insulation you choose, and whether the garage is finished or not. There are some preparatory tasks and considerations to keep in mind that will apply to every install:
Dress for safety: Wear goggles, a face mask, long sleeves, pants, and gloves to prevent insulation particles from touching and irritating your skin, eyes, and lungs.
Air things out: Maintain proper ventilation to make sure you’re not breathing in any insulation particles.
Remove your belongings: Insulation installation can get messy, so move your belongings out of the garage while the project is underway.
Take measurements: To purchase the right amount of material, you’ll need to measure the length and width of the garage ceiling and multiply the measurements to figure the area; then measure the distance between joists, as well as their depth.
Prepare the space: If you’re using a material that comes in batts or rolls, you will need to remove any drywall before installing.
Patch cracks: If your insulation is going to perform at its best, you’ll need to seal off and weatherstrip any cracks or gaps.
Add a vapor barrier: You'll first need to add a vapor barrier no matter what type of insulation you choose. Staple a plastic or foil sheet to the surface of the ceiling to prevent moisture accumulation and the mold and bacteria that can come with it.
Boost efficiency elsewhere: While you’re installing insulation, you might as well go the extra mile and make sure other parts of your garage are insulated. Check to make sure your garage door opener isn’t leaving gaps to the outside, insulate the walls, and add insulation to the garage door as well for the best results.
If you’re using a material like spray foam that requires specialized knowledge or rather just save yourself the hassle, you can always hire an insulation installer near you. Labor costs average around $1.50 per square foot, but the cost depends on the insulation material, its thickness, and the job’s complexity. The labor costs for most insulation jobs falls between $1 and $3, with the price for spray foam insulation sometimes topping that range.
The least expensive way to insulate a garage ceiling is to use fiberglass roll insulation. This type of insulation is widely available, comes in loose blanket form that’s easy to work with, and is ideal for insulating small, hard-to-reach places in your garage ceiling. For further cost savings, you can DIY the project and save on labor.
A garage ceiling needs a vapor barrier if it’s a heated garage or if you’re installing insulation in the ceiling. Without a vapor barrier, you risk moisture issues and mold growth. If you have an unheated garage and don’t plan on installing insulation that could get wet and harbor mold, the ceiling doesn't need a vapor barrier.
The best time to insulate a garage ceiling is when the weather is mild and dry. That means it shouldn’t be stormy, snowy, or raining, and the temperatures should be comfortable. Ideally, you’ll insulate your garage ceiling in the fall, before winter hits. Not only will you be the most comfortable, but you’ll also likely see the greatest energy savings heading into the colder weather with a newly insulated garage.
In some cases, yes, insulating an unheated garage can lead to mold and mildew. The issue with insulating a garage is that the interior will warm up and cool down more slowly than the exterior air, which can cause condensation inside the space. Where there is moisture, there is likely to be mold and mildew over time. Installing a vapor barrier can help avoid moisture and mildew problems in an insulated garage.
Mold can grow on garage ceiling insulation, which is why it’s important to install a vapor barrier behind the insulation and keep the space cooled and heated as you would your living area. Doing so will more or less eliminate the risk of mold growing on your garage ceiling insulation. You can also install a self-draining dehumidifier to help remove moisture, or opt for a foam board insulation or spray foam insulation that won’t harbor moisture and mold.
