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The Essentials of Exterior Insulation

September 11, 2015

As most homeowners already know, heat flows from a warm space to a cool space - it's natural. In the winter, heat has a tendency to flow from the heated indoor spaces to the outdoors - and that happens right through the walls. On the other hand, in the summer, heat has a tendency to flow from the outdoors to the interior of the home. This constant airflow (and heat transfer) is what points to the essentials of exterior insulation. Traditionally, residential home insulation was installed between the interior wall-studs. There was very little or no exterior insulation to speak of. It meant that there was plenty of leftover space that lacked insulation - and that meant that even the installed insulation didn't perform to its max. Where insulation did not effectively insulate, the potential for heat loss (referred to by experts as thermal bridging) was quite substantial. Exterior insulation is about preventing heat loss. And in a residential home there are so many opportunities throughout for heat to escape. The lack of exterior insulation not only contributes to heat loss - it also reduces the insulating effectiveness of existing insulation. For the professionals in the industry, augmenting exterior insulation is a sure-fire way to significantly impact existing R-Values, while providing additional R-Value. For today's energy conscious homeowner, exterior insulation is one of the better home-improvement projects, especially for those who want to dramatically reduce energy bills. Its because exterior insulation can cover 100% of the wall surface, leaving no gaps for air to flow back and forth, and therefore reducing heat loss, cool loss, and energy loss. Better still, exterior insulation will contribute to substantial seasonal utility savings. One of the many benefits of exterior insulation is that it can be installed over virtually any existing surface material. And depending on the product used, it's an excellent chance to address the condition of the "substrate" and to start from scratch. While there are countless insulation products on the market, and many contractors with the "answer", spray foam insulation is one application that has delivered proven results in many exterior insulation projects. It's a high-performance product, an all-in-one system, and a superior application that performs beyond other insulation products. For exterior insulation, it provides an airtight seal, an effective vapor barrier, and 100% coverage. When installed, conventional exterior insulation products often suffer from partial air loss or poor moisture control. These are not issues for spray foam insulation, and there are no spaces, shapes or edges that are too difficult to cover, seal or insulate. In fact, for the best long-term exterior insulation performance, spray foam is the preferred application. And beyond anything else, it offers the highest R-Value insulation per inch of any product. For the residential homeowner or commercial building owner, exterior insulation using a spray foam product will deliver the results - reduced energy usage and lower utility bills.

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

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

Greater Toronto Area

2 Guided Court
Etobicoke, ON
M9V 4K6

TOLL FREE: 1-800-265-1914

GTA East

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

TOLL FREE: 1-800-265-1914

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

Niagara Region

25 Lincoln Ave
St. Catharines, ON
L2P 2C7

TOLL FREE: 1-800-265-1914


Great Northern Insulation - Better Business Bureau Profile.

Homestars Best of 2021 Award

Best of 2021

HomeStars has ranked Great Northern Insulation as a company that goes above and beyond in every aspect of business for the year of 2021.

Homestars Best of 2022 Award

Best of 2022

HomeStars has ranked Great Northern Insulation as a company that goes above and beyond in every aspect of business for the year of 2022.


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

Trusted for Over 40 Years

Over 40 Years in Business

At GNI, we service your project with the most experienced staff in the industry. Ongoing professional development is an obsession at GNI and we will not compromise at any level to bring to our customers the very best Installers, Sales Representatives, Customer Care Personnel, Field Superintendents, Estimating and Technical Support to your project.

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

January, 2021 regulatory phaseout of hydrofluorocarbons (HFCs) with the introduction of WALLTITE CM01. Using hydrofluorolefins (HFOs) with lower global warming potential (GWP) compared to HFCs, WALLTITE CM01 is the next generation of spray foam insulation.



Heatlok® Soya HFOTM leverages Honeywell’s latest Solstice® Liquid Blowing Agent technology. This new hydrofluoroolefin (HFO) blowing agent is the most environmentally conscious blowing agent produced to date, with a zero ozone depletion potential (ODP) and a global warming potential (GWP) of 1, which is more than two orders of magnitude (99.9%) lower than HFCs used in this industry.


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).

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 Home Efficiency Rebate Plus program offers up to $10,000 in home reno rebates – 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.

As Seen on Love It or List It

The GNI crew have been featured installing insulation on Love It or List It - have you seen our logo in an episode?

Climatizer Cellulose


CLIMATIZER PLUS cellulose insulation is manufactured from a minimum of 85% locally-sourced post-consumer recycled newsprint. Non-toxic additives are applied to the uniquely fiberized paper generating a building material with superior thermal and acoustic properties, as well as exceptional resistance to fire, moisture, mould and pests.

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