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Industry Professionals

Meeting the needs of industry professionals means the highest level of product and service satisfaction.

Home Builders – Drywallers - Renovation Contractors - Architects and Engineers

General Contractors - Building Inspectors - Property Managers - Condominium Corporations

When 75% of your business comes from repeat customers, something must be working. And across Canada, our trades agree - with homebuilders, general contractors, and independent renovators finding themselves on the receiving end of product excellence, business and industry expertise, and the highest levels of customer service. For Great Northern Insulation, it’s really all about our clients - and that’s more than just a corporate slogan.

Based in Woodstock, Ontario, GNI works in practically every sector of the industry - from residential and commercial, to industrial and institutional. And we’re involved in every type of project: general construction; design/build ventures; renovations; and retrofits. We’ve been building our business for over three decades, having grown into six locations with over 200 employees – in short, we’ve built a well-respected reputation on our expertise, our reliability, and our professionalism.

For the real professional, doing it right the first time is worth the time, the effort, and the money. At GNI, it’s the only way we know, and our clients agree - this is a corporate philosophy that allows us to stand behind our workmanship 100%, and provide a commitment to the best service in the business. For today’s building inspector, property manager, or condo corporation, there is no other way – because performing a re-do, re-build, or re-make is costly and prohibitive.

Great Northern Insulation is Canada's largest full-service insulation contractor – a 100% Canadian owned and operated company, and a leader in the industry. Our service approach is unparalleled: with supervisory staff that expedite project inspections; trained technicians and certified installers; “Energy Star” trained sales teams and a dedicated customer-care staff that affords industry pros the kind of service they expect and demand.

Unfortunately, today’s business environment is fraught with pitfalls: runaway contractors who just don’t finish; scammers who do half the job; and shady operators who promise but don’t deliver. At GNI, there are no such scenarios. Our range of products is warrantied, our installers are insured and covered by WSIB, and your satisfaction is guaranteed. Not to mention, we’re competitive - not the cheapest, but without doubt, the best value for your dollar.

For Great Northern Insulation, nothing appropriates more focus than our commitment to customer satisfaction. We strive for integrity and fair practices in everything we do; the products we install carry the manufacturer’s warranty; installations are ruled by industry codes and standards; and problem issues are resolved in the framework of our “fix or replace” policy. Above all, we project manage in a manner that is eco-friendly and sensitive to the environment.

So what can we do for you? There’s really no need to compromise on product quality, installation expertise, or service - so count on us for experienced and highly trained staff; the right product for the job; punctual scheduling and timetables; and a guarantee on all of the above. We’ll show you that quality truly makes a difference - with trusted brand names, affordable solutions, and technical know-how that is above and beyond the rest.

home insulation in Ontario

Trusted for 35 years

great northern insulation satisfaction guarantee

100% Satisfaction Guarantee

professional insulation installation

Industry Leading Professionals

licensed and certified insulation contractors

Licensed & Certified


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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