Cheap Ways to Insulate a Garage

The garage is one of the most overlooked parts of a house. Some homeowners find it unnecessary to provide adequate insulation for their garages noting that the space is rarely utilized. 

Insulating your garage walls, doors, roof, and ceiling can have numerous benefits for your home. An insulated garage provides better climate control, and reduced energy costs and can help make your home cozier during the harsh winter and hot summer months. 

Cheapest ways to insulate a garage

You can choose between different options when looking to provide thermal and moisture protection for your space. The level of insulation depends on underlying climate conditions, budget, and the type of space undergoing the insulation.

Homeowners can opt for different techniques and materials to reduce the overall insulation cost. High costs may discourage people from engaging in the project considering that garages have large spaces and have limited use within other households. Garages can lose heat quickly and it makes perfect sense to look for additional ways to reduce heat loss, especially during the cooler months of the year. 

Some of the most cost-effective ways to insulate your garage include:

Spray foam Insulation

Spray foam is a popular option for homeowners looking to protect their homes from excessive heat and, moisture.  People prefer spray foam insulation because of its versatility, ease of installation, durability, cost, etc.

The average cost of installing spray foam installation on your walls is about $1.50 to $4.40 per square foot. Unlike other insulation techniques, it is best to have a professional install the foam on your garage walls, doors, and garage roof. Poor insulation can cause problems, especially for your garage door. Spray foam insulation can also help to protect your space from high moisture levels that can damage sensitive equipment and promote the formation of rust on iron surfaces within your garage. The insulation has an average R-value of 3.2 to 3.8 per square inch. 

The insulation foam has quality thermal protection capabilities and can protect your space for a considerable duration without the need for constant maintenance. Thicker foam insulation can also ensure soundproofing to make your space more quiet and appealing 

Fiberglass Insulation

Fiberglass is a popular choice for insulating a garage. The material is easy-to-install and offers reliable insulation for extended durations. Fiberglass consists of a blend of thin silica-based fibers and other reinforcing agents.

Fiberglass has excellent insulation qualities with an average R-value of 2.2 per square inch. People prefer using fiberglass insulation for their garages because it is remarkably easy to install and ideal for a DIY project with minimal technical expertise. The material is also affordable compared to other insulation types. The average cost of fiberglass insulation is about $0.30 to $1.50 per square foot. 

You can purchase the fiberglass as a roll, batt, or loosefill insulation. Proper insulation involves using fiberglass products to fill any air pockets and cover the garage walls, roofs, etc. When using roll insulation, for instance, you might have to use stay wires and other mechanisms to keep the insulation in place between the drywalls and other spaces.

Rigid foam Insulation

Rigid foam is a type of insulation ideal for garages and exterior spaces. The insulation consists of rigid boards made using polymers and thermoplastic compounds such as expanded polystyrene (EPS), extruded polystyrene (XPS,) and polyiso compounds. EPS and XPS are thermoplastic compounds that are vulnerable to damage on continuous exposure to excessive heat while the latter polysio can tolerate high temperatures for longer.

Rigid foam insulation has a moderately high R-value compared to other insulation types. Although you can purchase materials of varying thicknesses, the average R-value of the insulation is about 3.6 to 5.8 per inch. The product also has a moderate cost of about $0.25 to $1.40 per square inch. 

You can purchase rigid foam boards as 4 by 8-floor boards which makes the installation process straightforward. However, you need to ensure proper techniques such as tightly fitting the rigid boards to protect against thermal loss by air gaps and other spaces. A drawback of using rigid boards for insulation is that the product is susceptible to UV damage during continuous sunlight exposure. 

Cellulose Insulation

Cellulose is an ideal choice for insulating a garage. The primary material of cellulose insulation is recycled paper. The organic material offers high thermal retention qualities during cold weather and provides an organic insulation solution to indoor spaces within your home. 

You can use cellulose installation to control the thermal conditions in your garage. The average installation price of cellulose insulators depends on the material and installation technique. Blown-in insulation can cost about $0.60 to $1.80 per square foot while dense-packed insulation is slightly more expensive with an average cost of $2.00 to $2.30 per square foot. 

Cellulose insulation has an average R-value of 3.2 to 3.8 per inch. However, the R-value may vary depending on the material and installation technique. Using cellulose installation for your space also has additional benefits such as lower costs, fire resistance, mold resistance, etc. 

A downside of cellulose insulation is that it has a high moisture retention feature that can make your space more humid on continuous exposure to moisture. Having poor installation also makes the cellulose susceptible to sagging and settling which can cause unappealing shapes to appear on your walls, roofing, or garage door.

Reflective Insulation

Reflective insulation is an ideal way to control the thermal conditions of your garage, especially in hot climates. The insulation works by creating a barrier against radiant heat where instead of absorbing it (like other insulation materials), the material reflects the heat to the outside environment, reducing temperatures within the enclosed surface. 

Reflective insulation is light, easy to install, and durable. The primary material for making reflective insulation is aluminum where two aluminum foils encompass an air cushion usually in the form of bubble wrap plastics to create a protection film against heat loss or external heat access to your space. The R-value of reflective insulation varies depending on the thickness with an average rate of 3 to 17.

The price also varies depending on material thickness, installation fees, and additional variable costs. The average price for installing reflective insulation ranges from $0.60 to $2.40 per square foot. 

The lightweight nature of reflective insulation coupled with its excellent thermal protection features makes the product an ideal fit for garage doors, roofing, and walls. A downside to the product, however, is that it offers limited protection against the cold which limits its scope of application to relatively warm climates.

Should you insulate a garage?

It is always a good idea to protect your garage from temperature extremes, humidity, and fire. For some homeowners, insulating their garage spaces doesn’t rank high on their list of home improvement projects.

Garages can lose heat quickly when left exposed to low temperatures during the winter months. Heaters and other warmth-generating equipment have to stay on for longer to compensate for temperature differences resulting in increased costs for the homeowner. High humidity levels can also affect equipment and promote the growth of mildew, mold, and other fungi on sensitive items stored in the space. 

Lining your garage with protective material initially seems like a high investment venture with minimal returns and consequences considering the space is rarely used. Such notions explain why few people consider it a viable investment. However, providing thermal protection for your garage room can have many benefits that range from reduced energy costs to better climate control measures for your entire home.

It is vital to take measures to protect your garage from undesired external conditions and streamline your indoor conditions in an eco-friendly and sustainable setup. Besides, insulating your garage doesn’t always have to be expensive considering that there are some cost-effective ways to protect your garage on a budget.


Proper insulation techniques can help you save costs and provide an ideal living space for your family and loved ones. You can also choose from the different insulation types to work on specific parts such as the garage ceiling, roof, walls, etc.

Most of the ideas mentioned are ideal for most residential spaces and can provide thermal protection for extended durations. You can choose to engage in a garage insulation project as a DIY project or hire a professional depending on your level of expertise. 

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