Call Now1.800.265.1914

How to Insulate a Garage

July 17, 2020

The intention of this article is to help you learn how to insulate a garage for energy performance, fire safety, and proper ventilation. Both attached garages and detached garages can benefit from professional garage insulation and air sealing upgrades. For attached garages, proper ventilation and fire safety are of extra concern. This is to ensure that the occupants of the home are kept safe and separate from any potential health hazards, such as exhaust fumes or airborne particulates. 

If you would like to speak with our Customer Experience Team about your garage insulation, or if you would like to arrange a time for a free insulation assessment for your home, please include your contact details into the form that is linked below. We look forward to hearing from you! 

Why Should I Insulate a Garage?

Before you fully learn how to insulate a garage, it is important that you understand why it is important to do so in the first place. Depending on the type of garage that you own, and many other factors such as build design, timeframe, and budget, you may want to approach your upgrades in a different manner. For this reason, GNI strongly recommends that you have an insulation expert inspect your garage before you start making any upgrades or renovations. This recommendation also applies for new home builds, since it is beneficial for you to discuss your garage insulation options with a professional before you finalize your plans.

Overall, the different benefits of garage insulation vary from home to home, but these are a few of the improvements that homeowners may experience from a professional install:

  • Improved comfort
  • Increased resilience
  • Better temperature control
  • Upgraded health and safety (both in the garage and in the home)
  • Lower cost of utilities
  • Improved resale value of entire property
  • Improved noise reduction
  • Improved air quality

Garage Ventilation

For homeowners looking to secure a dedicated source of fresh air for their garage, both ventilation and air sealing need to be managed and purposefully controlled. This means that any areas where air can leak or intrude need to be identified and air sealed

Garage ventilation is also important in attached garages to make sure the home’s inhabitants are safe from unwelcome hazards, such as exhaust fumes or airborne particulates. The shared wall between the home and the attached garage should be properly air sealed to ensure an additional level of safety and energy performance. When the shared wall has effective insulation and air sealing, it provides the entire home with an energy performance boost. It does this by limiting energy loss that often occurs due to air leaks between the garage and the home.

How to Insulate a Garage with Spray Foam

To insulate a garage with spray foam means installing a product that provides an air barrier, a vapour barrier and improved energy performance all in one. Homeowners looking to climate control their garage can see tremendous results with spray foam. To best deal with exhaust fumes in both attached and detached garages, closed cell spray foam is often the better option. Since spray foam insulation can form its own air barrier and vapour barrier, only the thermal barrier is left to install - which can be as simple as covering the spray foam with drywall. 

DIY Garage Insulation

Using spray foam for garage insulation is a job that GNI recommends you leave to the professionals. Not only will this guarantee a precise and quality install that meets your exact specifications, but it also keeps you protected from any potential health hazards that may be present during the install. To learn more about using spray foam as garage insulation, please contact our Customer Experience Team at 1-800-265-1914.

How to Insulate a Garage with Fibreglass Insulation

Fibreglass insulation makes for an effective, affordable, and versatile approach to garage insulation. It is naturally non-combustible due to being made from sand and recycled glass, and can be easily installed as batts. Fibreglass insulation also makes for excellent soundproofing, which helps keep garage noises inside the garage and separate from your living spaces. 

To insulate a garage with fibreglass insulation, the first thing you will want to consider is the area you are insulating. For wall cavities, fibreglass batt insulation is both effective and affordable. However for the harder to reach places, such as rim joists, spray foam is likely to be the better option. In terms of garage insulation, both fibreglass batts and spray foam can be used alongside one another. In fact, they can both even be used within the same wall cavity through the flash and batt approach that is detailed below.  

How to Insulate a Garage Using the Hybrid Approach (Flash-and-Batt)

The hybrid approach to garage insulation, also known as flash and batt, involves the strategic use of both fibreglass insulation and spray foam within the same space. For flash and batt garage insulation, a layer of closed cell spray foam is installed across the wall cavity to provide both air sealing and moisture control. From there, cost-effective fibreglass batt insulation can easily be placed on top of the installed layer of spray foam, improving both energy performance and sound deadening. The flash and batt approach combines the strengths of both spray foam and fibreglass insulation, making it an effective and affordable option for homeowners to consider.

Interested in learning more? Fill out the form at the top of this page, or call us at 1-800-265-1914.

Western Ontario

935 Keyes Drive
Woodstock, Ontario
Canada N4V 1C3

Phone: 1-800-265-1914

Fax: (519) 539-7946
TOLL FREE: 1-800-265-1914

Southwestern Ontario

7035 Industrial Drive
Comber, Ontario
Canada N0P 1J0

TOLL FREE: 1-800-265-1914

Muskoka, Haliburton, Northern Ontario

1027 Elwell Park Road
Gravenhurst, Ontario
Canada P1P 1R1

TOLL FREE: 1-800-265-1914

Central Ontario

29 Ferndale Industrial Drive
Barrie, Ontario
Canada L4N 9V5

TOLL FREE: 1-800-265-1914

GTA East

103 North Port Road
Port Perry, Ontario
Canada L9L 1B2

TOLL FREE: 1-800-265-1914

GTA & South Central Ontario

450 Industrial Dr,
Toronto (Milton), Ontario
Canada L9T 5A6

TOLL FREE: 1-800-265-1914

Eastern Ontario

1035 Moodie Dr #1,
Nepean, ON
K2R 1H4

TOLL FREE: 1-800-265-1914


259 Campbell Street
Sarnia Ontario
Canada, N7T 2H3

TOLL FREE: 1-800-265-1914

Niagara Region

6260 Don Murie St
Niagara Falls, ON
L2G 0B4

TOLL FREE: 1-800-265-1914


Great Northern Insulation - Better Business Bureau Profile.


Best of 2017

From reputation to responsiveness, HomeStars consistently ranks Great Northern Insulation at better than 95% for customer satisfaction. Thanks to everyone for the great ratings! 

HomeStars 2018

Best of 2018

For the second year in a row, HomeStars consistently ranks Great Northern Insulation at better than 95% for customer satisfaction. Thank you again to everyone!

Homestars Best of 2019 Award

Best of 2019

For the third year in a row, HomeStars ranked Great Northern Insulation at better than 95% for customer satisfaction.

Homestars Best of 2020 Award

Best of 2020

For four years now, HomeStars has ranked Great Northern Insulation at better than 95% for customer satisfaction.


GNI is the Authorized & Trusted Insulation and Air Sealing Installer for Lowe’s

Enenrgy Savers

Energy Saving

Energy saving and energy efficiency is easier than one might think. Great Northern Insulation helps to identify performance issues, while taking advantage of improvement opportunities.

100% Canadian

100% Canadian

Great Northern Insulation is recognized as Canada's largest full-service insulation contractor. GNI is 100% Canadian owned, proudly serving Ontario customers since 1980.

Foam Masters

Do it right the first time
- with foam mastersTM

WALLTITE® ECO™ is a high-performance system, professionally installed by certified and approved specialists. Its C.C.M.C. approved (Canadian Construction Materials Centre) - with product quality guaranteed - and with installation by highly trained experts with the technical know-how to do the job right, the first time.


Gold Certification promise

GREENGUARD® Gold Certification ensures the strictest criteria for low-level chemical emissions. Certified products are safe for individuals with sensitivities (children/elderly) and safe for use in school environments and health-care facilities. The product certification is widely recognized by the LEED Rating System (Leadership in Energy/Environmental Design).

Insulthane Extreme

Insulthane® Extreme

For the ultimate in high performance spray foam insulation, Insulthane® Extreme is the professional choice for residential, commercial, and industrial application. With improved thermal performance over other products, Insulthane® Extreme has an exceptionally low Global Warming Potential (GWP). Considered environmentally friendly, this next generation spray foam insulation is non-ozone depleting, and exceeds specifications of other HFC product alternatives.


Multi-attribute product certification

ECOLOGOTM is an accredited sign of environmental performance – holistic – green – sustainable - and compliant with strict, third party standards. Life cycle criteria for product certification may include manufacturing and operations; health and environment; product materials and performance; and product innovation, development, and management.


3MTM products.
Quality + Performance = Savings

3MTM energy-saving products are designed to keep warm air in, and cold air out, while keeping energy bills down. Products optimize energy efficiency in buildings and homes; improve indoor environment for occupants; and effect the reduction of seasonal energy costs. 3M products are authorized for LEED credits (Leadership in Energy/Environmental Design).


Baeumler ApprovedTM
Professional, Certified and Insured

Baeumler ApprovedTM gives you peace of mind when connecting with contractors, trades and home service providers. All Baeumler Approved members have demonstrated high quality work for customers and other trade professionals. Members must also have Workers Compensation, liability insurance of at least $1,000,000 and prove professional certification.

Holmes and Holmes

Holmes and Holmes


Mike Holmes and his son Mike Jr. (MJ) convert MJ’s bachelor bungalow into a two-storey home for MJ and his girlfriend Lisa. Choosing the newest materials and build techniques, the father and son team follow Mike’s famous motto – “Make it right.” The show can be watched on HGTV and DIY Network.


Enbridge Incentives

The Energy Conservation Program provides incentives of up to $1,600 to customers who achieve energy efficiency and fuel savings – and Great Northern Insulation can pave the way.


Great Northern Insulation proudly abides by a renovation-specific Code of Conduct set by RenoMark™.


We are Verified & Bonded by eRenovate. When you choose to proceed with our services through their platform, you receive the gaurantees set forth through their program.

Please, enter a valid value

Incorrect values!