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Insulating Old Houses for Personal Comfort and Energy Savings

May 23, 2016

Keeping old houses comfortably warm and energy efficient is tough. Older homes weren't usually fitted with insulation. When they were, the materials often settled, lost their insulating value, and sometimes deteriorated. Today, home insulation options are abundant, with a myriad of products that are both cost-effective and energy saving - the big decision is what to do and how to do it. The first step in insulating an old house is to determine the status of the home's insulation. And while a cursory homeowner assessment might be adequate, it's best to have a professional assess the entire house - from attic to basement to exterior walls. An expert can accurately evaluate the overall status: the scope of insulation, the extent of air leakage, and the options for re-insulation. One of the biggest problems in an old house is air leakage. In winter, heated inside air leaks out, and in summer, warm outdoor air creeps in. Old chimneys and fireplaces are a definite source of air leakage, while aging doors and windows also contribute. But most important is to address the top of the house - the attic and roof cavity, which is where most indoor heat rises and escapes. Depending on the age of the house, there may well be dangerous and even hazardous insulation products installed. This is another reason why a professional assessment is preferred, especially if asbestos or urea formaldehyde are suspected. Inasmuch as these materials might have been acceptable at the time, today they must be remediated, with full restoration work recommended. For many insulation contractors, the preference when insulating or re-insulating an old house is to begin in the attic - a place with the best return on investment. For the professionals, insulation is only the start. It's also important to ensure effective ventilation and moisture control. It's about creating a complete "system" that incorporates air sealing, thermal insulation, and ventilation. Choosing the right type of insulation product for an older house is also a critical decision. Today, many insulation professionals are installing spray foam insulation - it's the most multi-purpose application available. When professionally installed, specifically in the attic and roof, spray foam will block airflow, control moisture, and insulate at a very high R-Value - all in one application. When installed throughout an attic, spray foam covers the space with a thick, dense "envelope". Everything is completely covered - the attic support beams; the electrical wiring; the heating and return ducts; and all of the cracks and crevices that surround. With spray foam, the finished space is fully airtight, moisture-proof, and insulated with a very high R-Value rating per installed inch. In older homes, the spray foam approach will deliver more benefits than other options, whether it's in the attic, the walls, the basement, or the floors. It is, however, a premium product, and may not suit all budgets. This is where a "hybrid" alternative might be a viable appropriate. It's a way of combining spray foam with a secondary insulation product to ensure cost-effectiveness.

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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