Why and How To Insulate Your Garage (Complete Guide)

You may think insulation is extra work, and spending that makes little sense. But there are many benefits to doing it. Why and how to insulate your garage?

Insulating your garage keeps the temperature, moisture, and noise under control. This means you can use it year-round. Insulation can be self-installed with the help of usual home tools. You can usually purchase insulation materials from home supply stores.

In this article, we explore why you should insulate your garage. We also look at how you can select the right insulation type and material for your garage. 

Then, we explore how to install insulation on your garage wall, door, and ceiling. Finally, we answer some of the most common questions people have about insulation in a garage. 

Why Should You Insulate Your Garage?

Insulating your garage keeps the temperature, moisture, and noise under control. Insulation also prevents winds from entering your garage. Installing insulation also increases energy efficiency and may help to increase property value.

On the surface, insulating your garage may feel like additional work and money. However, there are many good reasons to insulate your garage. These include:

Control Temperature

Insulation’s main job is to isolate the air inside your garage from the outside. This means you create your own micro-climate inside your garage. This allows you to control the temperature inside it better. 

For example, an uninsulated garage will be hot during summer. If you spend time inside, you will feel like you are in an oven. This is because the air in the garage gets heated by the sun. 

With insulation, the heat from the sun does not reach inside your garage but stays outside. As a result, your garage air stays cool. 

The same effect could also happen during winter. The cold air does not cause the air inside your garage to become cold. Even if it feels cold, you can turn on your heater, and the insulation will keep the warm air inside your garage.

As a result, you can now use and spend time in your garage year-round without worrying about it turning into an oven in the summer. You also would not be worried about it turning into a freezer in the winter. 

Control Humidity

Another reason you want to install insulation is to control the humidity. Humidity is one of the biggest factors that cause machines, tools, and materials to break down. 

Humidity causes things to rust and wood to rot. They also cause things like paper or paint to be moldy and no longer usable. 

Many insulation materials actually absorb moisture very well. This helps to keep the air inside your garage to be dry. This prevents moisture damage on the things you keep inside your garage.

Control Noise

Many insulation materials are dense enough to even help insulate noise. In this case, insulation can lower outside noise from entering your garage. It can also prevent the noise you make inside your garage from traveling out. 

This can mean good things in many ways. You can work in peace and quiet in your garage without being disturbed by outside noise. 

On top of that, you can also crank up your power saw or Metallica jams late at night without waking up your neighbors.

Control Draft

Another thing that makes the garage feel cold is the draft. Suppose the outside wind is blowing against your garage. In that case, some may penetrate through the gaps in your garage wall, windows, etc. 

This makes the already cold air inside your garage move, making them even colder due to the wind chill effect.

Installing insulation helps to reduce drafts from entering your garage. This keeps the air inside the garage still. This should reduce wind chill and make your garage a nicer place to hang out and do things.

Increase Property Value

Many of us like to see our house have more resale value over time. One of the best ways to do that is to install upgrades to the property. 

Insulating the garage is one of the best ways to increase property value. This is because many homebuyers actually care about the garage. 

It is a place many people park their cars and enter their houses. They want to get in or out of their garages warm. They would see it every day too. So a well-insulated garage is valuable in many people’s eyes.

With a higher valuation for your house, you can refinance the house. You can also just wait and reap the profit when you sell your house later. 

Energy Efficiency

Another way insulation helps with your garage is energy efficiency. Energy efficiency basically means you get more value out of your energy bill. In simpler terms, it means you lower your energy bill. 

We may often have our water heater installed in the garage. If the garage is not insulated, the heater unit will be cold. This means it needs to use more power to warm up the water. An insulated garage will not have this issue.

On top of that, suppose you turn on your heater or cooler in your garage. In that case, the insulation will prevent the warm or cold air from escaping. This means you do not need to use too much energy to adjust the climate of your garage.

Protect Items Inside Your Garage

For many of us, we store things in our garages. These could range from machinery to tools, down to important documents. One of the fastest ways to destroy these things? Extreme temperature and moisture. 

Extreme heat browns out the papers and melts oils and grease that lubricate your tools and machinery. Under cold temperatures, the grease and oil may freeze up. As a result, they fail to protect the moving parts of your tools and machines. 

Moisture can also cause rusting or general rot of wooden furniture and things in your garage. 

With insulation, you get to protect your things and tools better. This is because you will limit temperature fluctuations and control the moisture inside your garage better.

Read More: What is Safe to Store in the Garage

How To Select The Perfect Insulation For Your Garage?

When selecting insulation for your garage, observe the types, materials, and r-value. You also want to decide if you want reflective insulation. Finally, balance the insulation you want with your budget.

Suppose that you are now convinced of the importance of insulating your garage. The next step is to decide what insulation to install. This cannot be easy, as there are many factors you need to balance to arrive at the best choice for your needs. 


Insulations can come in many types. Insulation types refer to the form of the insulation. The form itself will then determine how you will install them. The most common form of insulation type is batt and roll. 

Batt insulation can be imagined as tiles; they come in pre-cut 2 x4 feet pads that you then stick to your garage wall. Roll insulations are not pre-cut. Instead, they come in a 20-foot or 40-foot roll. You then cut the insulation roll into the needed sizes before putting them on the wall.

There are also many other types of insulation, such as spray-on, loose-fill, and so on. Each of these insulation types comes with its own upside and downsides.


Insulation material refers to the ingredient in the insulation you are using. Depending on the types of insulation you are using, you may select from a different set of materials. 

Take, for example, batt insulation. Batt insulation can be made from many materials, such as fiberglass, wool, and mineral wool. Other eco-friendly materials include recycled denim, soy fibers, or hemp. 

The most common insulation material is fiberglass. You may see them as pinkish pads people install on their garage walls, doors, ceilings, and floors. 

For spray-on insulation, the common materials include liquid latex and polyurethane. After spraying to the surface, they expand and harden into a thick surface.

READ MORE: Insulation Types And Materials – The Ultimate Guide


When selecting insulation, you also want to look at the R-value of the insulation. R-value refers to a material’s ability to reduce the heat transfer rate. The higher the R-rate, the more it can do that. 

This means you want one with the highest possible R-value when selecting insulation. The higher the R-value, the better the material insulates your garage. When shopping for insulation, you will see the R-rating printed on the packaging. 

Conventionally, insulation with the best R-value is rigid polystyrene boards. Some spray-on insulation can have a high R-value as well. They can be expensive, however. In many cases, regular fiberglass batt may be enough insulation for a home garage.

Read More: R-Value


Insulation materials can come in many types. Each will have its own upsides and downsides. One of the major differences these materials may have is safety. 

One example would be fire safety. Some insulation materials are fire retardants. This means they do not burn up when in contact with fire. These materials include wool, cellulose, mineral wool, fiberglass, and more. 

Some materials are less fire retardant, such as recycled denim. If a fire hazard is something you are concerned about, look for fire-safe materials. 

Another issue is health safety. Some insulation materials are made of natural, organic things. These would be safer and would not release any off-gas or toxic compounds. These include materials such as ThermaCork, natural wool, or latex. 

Some man-made materials may release toxic compounds over time. Some may break down into small, fine particles that you may breathe into your lungs. Over time, they may cause respiratory irritation and issues. 

These include materials such as fiberglass, mineral wool, and so on. Stay away from these materials if these issues concern you.

Reflective / Radiant Insulation

You can also start thinking if you want a layer of reflective or radiant surface on your insulation. You may see them as a thin sheet of shiny metallic material, usually aluminum, on one side of your insulation.

Their job is to reflect heat and UV rays away from the insulation material. This further improves the insulation’s R-value. This means reflective and radiant sheets are helpful in summer.

However, it does not do much in winter, as it does not reflect cool air. As a result, some people choose not to have them on their insulation. You will need to decide for yourself if you need one for yourself.


Finally, we need to look at the finances, or cost. Depending on your insulation’s type, material, and R-value, the cost can be different. The total area you intend to insulate will also affect your final budget. 

If you intend to DIY the insulation work, you can save a lot of money. However, some insulation is best hired out to professionals, such as spray-on insulation. If you intend to hire out the insulation work, you will need to budget more money to pay the contractors too.

For the best savings, install batt or roll fiberglass insulation and do it yourself. These are simple to install insulation, which should be manageable for most people.

How To Insulate Your Garage Wall?

To insulate your garage wall, start by preparing the tools and materials. Then prepare the wall surface by cleaning and removing any obstructions. Next, place the insulation panel and then secure it in place. Finally, cover up the wall using a plywood sheet or drywall.

Insulating your garage wall is not rocket science. You also do not need too much technical skill to do it, as it does not require you to perform serious structural work. You can also complete the work with some basic home tools only. 

For the guide below, we assume you are installing fiberglass batt insulation. If you want to install spray-on or blow-on insulation, the steps below may not apply. This is because the process is different. 

Prepare The Tools & Materials

Start by preparing the tools and materials. In many cases, you may already have most of these tools lying around your house. You do not need any specialized tool to perform this job. 

Aside from that, also ensure you have safety and protective gear on standby. Some insulation materials can be skin, lung, and eye hazards. You do not want these materials to enter your body and cause issues. 

Have the following tools prepared for a smooth sailing job: (links to Amazon)

When it comes to materials, ensure you have enough of your insulation material ready. You want to be able to cover the surface you intend to insulate. 

Do this by measuring the total surface. Then do some calculations to ensure you purchased the right amount of insulation for the job. When in doubt, by a little more. Having a little extra insulation lying around is always better than not having enough.

Prepare The Surface

The next step is to prepare the surface for installation. Since you will cover the wall with insulation materials, you want to ensure they are clean. 

You do not have anything on the surface that may cause the insulation to fall off in the future. You also do not want any obstacles, such as wires or pipes. They may cause issues when you install the insulation pieces later.

  1. Start by clearing out the garage. Move any further that is in contact with the wall away to allow space for you to work. 
  2. If your garage has drywall coverings, you also want to remove them. You will install the insulation between the outer wall and the drywall of your garage. 
  3. Now that you can see the surface give them a good clean. Use a broom to sweep away any cobwebs. You can also use a vacuum cleaner to clean the surface from dust. 
  4. If the wall surface has other things on it, try to see if you can remove them. A clean surface is important so that your insulation can adhere well. Also, clear out the stud cavities. 
  5. You also want to ensure there are no obstacles. They could pose problems when you install insulations. In most cases, there may be wires or pipes. 
  6. If possible, remove the wires from the wall surface. You can always put back the wire after you have installed the insulation.

Install The Insulation

Now that the surface is prepared, you can install the insulation pads. 

Before you start, ensure you change into clothes that cover your skin. This is because some insulation can be a skin irritant. Also, wear masks to avoid breathing in these materials. Put on gloves to protect your hands too.

  1. Start by locating any small or odd spaces on your garage wall. Measure them out, and use the cutter to cut out the shapes from your insulation batt. 
  2. Fit the cut-out into the spaces. The insulation needs to be flat and evenly distributed. The insulation should also be deep to feel the space between the wall and the frame’s edges.
  3. Always cut out custom pieces that fit well. Avoid the temptation to simply smash, squish, or shove insulation into these places. 
  4. Secure the cut-out in place with the hammer tack. If your insulation has a stick-on adhesive surface, roll it to ensure it has good contact with the wall.
  5. Repeat steps 1-4 until only straight, flat uninsulated surfaces remain.
  6. Now measure, and cut the batts to the necessary size. Make sure they fit well with the wall studs. 
  7. Start from a corner and cut and attach the insulation batts to the garage wall. 
  8. When securing the insulation batt, staple the paper face of the insulation to the stud’s side. Leave the face of the stud clean. This is because you need the face of the stud to install the drywall on top of the insulation. 
  9. Once all is completed, walk around the check if there are any noticeable gaps. Patch these by cutting pieces of insulation batts to fill the gaps. 
  10. If you need to, you can install a vapor barrier. 

Cover The Insulation

Now that the insulation is put in, you can now proceed and cover the insulation. In many cases, people use plywood sheets. This is because garages do not need very nice surfacing. However, if you prefer a more refined finish, use a drywall instead.

Aside from drywall, options such as OBS (Oriented Strandboard) exist. You can also use FRB (Fibre Reinforced Boards), Shiplap, or Slatwall. We cover all the possible garage finishing walls and their installation process here.

How To Insulate Your Garage Door?

To insulate your garage door, decide on the insulation type and material. Then determine the amount of insulation needed. Next, prepare the garage door surface and then install the insulation. Test to ensure the insulation does not interfere with the garage door’s operation.

On the surface, installing insulation on the garage door may look more difficult. There are so many moving parts with garage doors. However, installing garage door insulation is also doable for most people. 

This is because there are actually garage door insulation kits in the market. These kits come with pre-cut insulation batts that fit into your garage doors. This makes the job much easier. 

However, you can get regular insulation rolls and cut out the necessary pieces. You may be able to save money this way rather than buying garage door insulation kits.

To start insulating garage doors, here are the steps:

Measure The Garage Door

The first step is to measure the garage door. Once you do this, you can know how much insulation you need. 

There are two ways to do this. First is to measure the whole door and then buy roll insulation. This is a more cowboy approach, but likely to save you money.

The second method is to measure the individual door pieces. You can then look for garage door insulation kits with similar sizes as your door pieces. This may be easier to install but likely a little more expensive.

Pick Up The Right Garage Door Insulation

Check for the material used when picking up the right garage insulation kit. Also, check on how they adhere to your garage door. 

Some garage insulation kits come with stick-on adhesive pads. These are simple; you just stick them onto your garage door. 

Some may need to be secured to your garage doors using special clips. If this is the case, your insulation kit should come with it. 

If you want to be old school and save money, go cowboy and pick up regular insulation rolls. Cut the insulation out with a knife, then stick it to your garage door. 

READ MORE: Best Garage Door Insulation Kits

Clean The Garage Door Surface

Before you install the insulation, spend some time cleaning up the garage door surfaces. Focus on the surfaces where your insulation will stick.

Start by using a brush and sweep away any dust and debris on the surface. You can also use a moderately damp microfiber cloth and wipe the surface to clean it. 

Suppose your insulation pads come with stick-on stickers. In this case, you want to ensure the surface is free from dirt, oil, and grease. 

Use some isopropyl or rubbing alcohol and wipe the surface with it. This ensures the sticker on your insulation can adhere to your garage door well.


When you install, ensure the pads are cut into the right size. If there are noticeable gaps, fill them by cutting out insulation pieces. 

In most cases, insulation pads for garage doors come with two attachment styles. One uses stickers, where you adhere the insulation to the garage door panels. 

For these types, ensure you use a roller to push the insulation down to the panel. This helps the stickers to get the maximum attachment. 

Another type uses special clips to clip the insulation pads to the garage door panels. These should come together with your garage door insulation kit. 

Test And Calibration

Now, once you have put everything in, do a check and try to operate your garage door. You want to ensure the insulation does not interfere with the garage door’s operation.

In some rare cases, you may notice that the door is operating slower. This may be because the insulation added some weight to the garage door. In this case, consider upgrading your garage door’s torsion or extension springs.

READ MORE: Insulating the Garage Door

How To Insulate Your Garage Ceiling?

To insulate your ceiling, the best way to do it is to install the insulation from the attic. You can also use blow-on or spray-on insulation for an easier job. Be careful while moving around the attic, and only step on the joists to avoid accidents.

When it comes to insulating your ceiling, one of the biggest challenges is the height. Insulating from the bottom side of the ceiling may not make sense. This is because you will need to climb up ladders repeatedly to install them. 

The better approach is to install it from the top side of the ceiling. This means you will need to access your ceiling from the attic. Approaching from here should make the installation job much easier.

Prepare The Surface

As usual, spend time cleaning the ceiling surface. Since the top of the ceiling is a horizontal surface, it will likely have a lot of dirt and debris. Use a broom to sweep and clean the surface, and then vacuum the surface to remove any minor dirt. 

You can go a step further and mope the surface with a wet mop. This could remove any possible dirt and debris. If you take this step, allow the surface to dry first before proceeding.

Batt Or Roll Installation

If you intend to use ball or roll insulation for your ceiling, follow the steps below when installing:

  1. When moving around the attic, ensure where you are stepping. Step only on the joists to be safe since they would be strong enough to support your weight. 
  2. If required, cut out a 2 x 4 piece of solid wood, and use it to bridge between the joists. It will be safer for you to move around too.
  3. Start by looking for any odd-shaped surfaces first. Use a knife, and cut out the surface. 
  4. Ensure the insulation cut-out fits well. It should not show any fold or squish marks. If yes, trim the cut out. 
  5. Secure it to the surface. 
  6. Repeat steps 3-5 until all irregular surfaces are covered and you are left with straight, flat surfaces. 
  7. Cover all surfaces with your batt or roll insulation. Take note to ensure the materials do not have a noticeable gap between each other. Gaps will lower the effectiveness of the insulation.
  8. Secure the insulation to the surface. You may use stick-on adhesives or a hammer tack for this job. 
  9. Once everything is completed, go back and recheck the work. Ensure no noticeable gaps are present. If there are, cut out pieces of the insulation and then patch the gap. 
  10. If you intend to use the attic, place a layer of flooring on top of the insulation. Solid wood planks are often the choice for many garages.

Spray Installation

If you intend to spray insulation in your ceiling, you can do so from the top and bottom. This is because you do not need to climb up ladders. Just spray the insulation from the ground instead. 

Spray insulation may be better if your garage’s joists are visible from your garage floor. This means you only need to spray the insulation to fill between the joists. And then cover them up with plywood or OSBs to make a ceiling. 

If you intend to spray on your insulation from the floor to the ceiling, here are the steps:

  1. Start by removing all the things inside your garage outside. You can also cover them up with a tarp or coverings. This will protect them from catching any insulation. 
  2. Start by cleaning the ceiling. The ceiling may often be full of cobwebs, debris, and dust. You can use a broom to sweep the surface clean. 
  3. If you want a better result, consider using a pressure wash and water blast the ceiling to clean it. Allow some time to dry before proceeding. 
  4. Next, prepare your spray insulation. You may operate from a pressurized tank, depending on the material and type.
  5. Assemble the machine as the maker directs, and test spray on a small surface to confirm all is working. 
  6. With foam spray, run your passes moderately to cover the surface, and then stop. Take some time to observe if the foam expansion reaches a similar thickness as the joists. If not, adjust your passes to be slower.
  7. Continue the process until all the spaces have been sprayed. Allow the foams some time to harden.
  8. Cover the ceiling with ceiling sheets, plywood, or OSBs if you need to. 

Read More: Insulating the Garage Ceiling

Garage Insulation Q&A

Should I Insulate My Garage Floor?

Garage floors can be really cold during winter months. Installing a layer of floor insulation could make the space nicer to work. Plus, your insulation is as good as its weakest link. Heat, moisture, or cold can make it to your garage from the floor, ruining all your hard work. 

You could use an insulation board or install a floor heating system. Consider installing a radiant floor heating system when installing a new garage floor. You can also consider an epoxy floor, as they work great with floor heating.

However, remember that installing a radiant floor system is not a DIY project. You will need to hire a plumber specializing in installing this type of floor heating system.

Expect to pay $5 to $9 per square foot to install the system, plus the boiler’s cost. But the resulting system is ideal for heating the garage workshop. 

How Long Does Insulation Last?

Most insulation is designed to last many years if not decades. You can check for the lifespan of your insulation from its packaging. You can also call the maker or manufacturer to get a ballpark figure. 

Insulations’ biggest enemy is moisture, as it can shorten their life. When insulation gets wet, it packs down. It loses its lift, and when that happens, it also loses some of its thermal value. Some longer-lasting insulations are less sensitive to moisture. These include wool, foam, or rigid boards. 

Must You Staple Down Insulation?

Stapling down insulation is the most common way to secure insulation to a wall or other surfaces. It is a popular approach because it is cheap and fast. A quick tack is all it needs. 

But, if you prefer not to use a tack, consider insulation materials with an adhesive sticker. These usually allow you to stick the insulation to the surface without the need to use a tack. 

However, ensure you properly clean the surface for the adhesive to work well. Aside from sweeping and vacuuming, clean the surface with a degreaser or isopropyl alcohol. This will get rid of any remaining oil and grease. These may seriously affect the ability of the adhesive to work.

What Is The Most Energy Efficient Insulation?

The most energy-efficient insulation provides the best temperature control. This prevents you from having to turn your heater or cooler on full blast. As a result, you save paying on your electricity bills over time. 

In this case, the most energy-efficient insulation would be the spray-on insulation. This is because it has the highest R-value compared to other insulations. This may be a great upgrade to get if you are remodeling your house too. 

However, suppose spray-on insulation does not work for you. In this case, consider rigid board insulation instead. These are also highly rated, with an R-value second to spray-on insulations.

Do I Need To Heat My Insulated Garage?

In most cases, you must heat your insulated garage, especially in winter. The insulation can stop the cold air from coming into your garage. But you still need to warm the air inside your garage too. 

However, since your garage is insulated, you are in for some treat. When you turn on your heater, the warm air stays inside your garage and is not lost to the outside air. This means you may not need to turn your heater on full blast, and you can still enjoy nice toasty air. 

For the best garage heaters, check out our ultimate guide on garage heaters here. You can check our guide on garage air coolers too.

Do I Need A Vapor Barrier?

You may read up on vapor barriers when researching insulations. A vapor barrier prevents water vapor from passing into your walls and ceilings. This issue may be more evident during cold weather.

Suppose moisture from either direction builds up within stud or cavity walls. In that case, the moisture will cause the insulation to lose its R-value. Mold and rot can also set in over time.

Vapor barriers are generally needed in areas with cold or mixed climates. Some insulation has facing already built-in, so check which type you have.

It may be wise to check with local building codes and consult an expert to determine if your garage needs vapor barriers. When installing, be sure to protect any openings where air could leak.

Vapor barriers are somewhat controversial. This is because they can keep moisture from seeping into a structure and from seeping out. This leads to mold and mildew growth.

There may already be a vapor barrier between the sheathing and the siding. Some regulations need a vapor barrier inside the insulation in living spaces, and some don’t. Consider checking with your local building authority, but it’s probably not too important, since it’s a garage.

How Much It Cost to Insulate a Garage?

The garage insulation cost will vary based on geographic location, the material selected, and the space’s overall size. Check the up to date guides below.

Homeadvisor insulation cost guides

Homeguide insulation cost guides

Read more about garage insulation in this article.

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