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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

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.

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

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.

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.


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.

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?

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