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Check Your Attic Insulation Before Winter!

November 25, 2015

To say that an attic must be insulated properly is an understatement. And to think that the attic insulation is only about creating indoor comfort is equally understated. Truth is, attic insulation should be preventing heat loss from inside the home and keeping indoor temperatures controlled (whether it's summer or winter). Yes - indoor comfort will be enhanced, but more importantly, energy efficiency will be greatly improved, and that means saving money on utilities. As winter approaches, many homeowners reflect back on last winter, and the "ice damming" that they witnessed. This is a common problem, sometimes with bad outcomes, and usually has little to do with the roof or the eaves trough. It's simply an attic insulation problem. And while having clean troughs is absolutely a must, "ice damming" is usually a result of heat loss, which is a result of poor attic insulation. Snow melting and re-freezing is the cause of "ice damming". Roof snow melts because heat is dissipating upwards through the attic. Because of the outside cold temperature, the melted snow then re-refreezes and causes the damming. Simply put, heat shouldn't be dissipating from the attic, and proper attic insulation will ensure that this does not happen. In short, the attic cavity must be sealed off - and it's done with an effective vapor barrier and with a quality attic insulation product that completely seals the attic space. For the professionals, attic insulation is about creating a "system". The vapor barrier will prevent moisture from collecting. The attic insulation will prevent air movement and air leakage. And proper attic ventilation will assure balanced air circulation. Everything works together - stopping unwanted heat loss; allowing attic insulation to do its job; and averting the formation of ice and damming. But it all has to be done properly, and without taking any shortcuts. The first step with attic insulation is to check the of the attic - and this should be done well before the winter. A typical homeowner can certainly do a cursory overview - but a professional knows what to look for, and where to spot the challenges. Attic insulation requires expertise - there may be a need to replace deteriorating insulation; it may be possible to "top up" existing insulation; or for that matter, there may be a need to do repairs before any insulation work. It's also possible to get into a DIY project with attic insulation - but the professionals really have an advantage here. Good insulation contractors have product knowledge, installation expertise, and project experience that allows for good recommendations for the homeowner. This would be particularly true when creating an attic "system" that incorporates the vapor barrier, the attic insulation, and the ventilation into a well-functioning building envelope. Today, many contractors are recommending spray foam insulation for the attic. It's ideal for an expansive space like the attic, and it's totally multi-purpose, providing more benefits with one application than any other product on the market. Spray foam completely seals the entirety of the space; it serves a combination air and vapor barrier; and it provides better R-Value than anything comparable. When it comes to attic insulation, nothing comes close.

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

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29 Ferndale Industrial Drive
Barrie, Ontario
Canada L4N 9V5

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2 Guided Court
Etobicoke, ON
M9V 4K6

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

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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


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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

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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.


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The Home Efficiency Rebate Plus program offers up to $10,000 in home reno rebates – and Great Northern Insulation can pave the way.


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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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