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Ask Questions Before Hiring a Roofing Contractor

May 06, 2014

roofing contractorIf you're planning on roofing your home sometime in the near or far future, you may want to research your options quite carefully, because this long-term investment will definitely reflect the value of your home and curb appeal.

Trust the professional, but the Correct one! How, you may ask? Well, here's a checklist from National Post to help you on the journey.

  1. Are they certified installers and covered under the warranty plan of the roofing product?
  2. Are they fully licensed in your area to perform roofing work?
  3. Are they adequately insured for your protection?
  4. Do they have a proven reputation for providing quality roofing?
  5. Do they treat the roof as an integrated system?

Other than this checklist, keep these tips in mind: - Roofing materials vary from the traditional three-tab or strip shingles that have been around for many years, to architectural shingles, treated cedar, composite or metal roofs.

- When deciding which product to use, try to consider the overall style and look of your house that will fit in with the neighbourhood.

- Ask your installer for locations where you can see the material actually used on a house.

- Proper attic ventilation systems allow a continuous flow of outside air through the attic. It consists of a balance between air intake (at your eaves or soffits) and air exhaust (at or near your roof ridge). Consider a minimum of at least one square foot of attic ventilation for every 200 square feet of attic space. Proper ventilation in the attic will reduce heat buildup, moisture and condensation, weather infiltration and ice dam buildup. Poor attic ventilation can ruin your insulation, destroy your shingles, and raise your energy bills.

- When installing a new roof, it's always best to remove the existing roofing materials. This reduces excess weight and gives you the opportunity to properly examine the roof deck for defects or damages. It also allows installation of waterproofing underlayment.

- Waterproofing underlayments (ice and water shield) should always be used in valleys, on ridges, at eaves and around chimneys and skylights. On low-pitch roofs, the entire roof should be covered with ice and water shield before installation of shingles. This will create a watertight seal that keeps water out at the most vulnerable areas of your roof.

- Pay attention to the manufacturer's warranty. Warranties range from 20 years to lifetime. There are two types of coverage that you should ask your contractor about: Coverage against material defects and coverage against workmanship errors. Look for warranties that cover materials and labour.

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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