Insulation Contractor in Ontario
Insulation work covers attic top-ups, wall cavity fill (batt, blown-in cellulose, or spray foam), basement rim joist sealing, and full envelope upgrades on older homes. In Ontario, most of this work is driven by heat loss through the attic and uninsulated rim joists, so a contractor who actually air-seals before adding insulation will save you more on heating bills than one who just blows in fibreglass and leaves. We track 110 insulation contractors across the province, from small attic-only crews to larger firms that also handle spray foam and basement retrofits.
When you're comparing quotes, look past the price per square foot. Ask what R-value they're installing to and whether it meets current Ontario Building Code minimums for your home's age. Ask whether they air-seal penetrations (pot lights, plumbing stacks, wiring holes) before insulating, since skipping this step lets warm air bypass the insulation entirely. Check whether they're WSIB-covered and carry liability insurance, and for spray foam specifically, ask whether the installer is CUFCA-certified. A written scope that specifies material type, thickness, and coverage area matters more than a verbal estimate.
Our ranking at the best insulation contractors in Ontario scores every company on review volume, rating consistency, and how responsive they are to customer feedback over time, not just a single star average. For the full breakdown of how we weigh those factors, see our methodology.
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All insulation contractor, ranked by score and relevance
We found 200 businesses offering insulation contractor; 7 met the criteria for the scored directory. The order weighs each business's overall score by how much of its reviewed work is insulation contractor, so a lower-scored specialist can rank above a higher-scored generalist. Filter and sort below, or open the full map view.
When you submit a quote or contact form through this site, your enquiry may be shared with partner providers who can do the work. We may earn a referral fee from these partners, but our rankings and scores are determined solely by our published method and are never affected by referral fees.
Common questions about insulation contractor
- How much does insulation installation cost in Ontario?
- Attic top-ups typically run a few hundred to around $1,500 depending on square footage and current depth. Full wall or basement insulation with blown-in or batt material often lands in the $2,000 to $6,000 range for an average home, while spray foam costs more per square foot but seals air leaks in the same step. Get at least two quotes since pricing varies a lot by crew size and material.
- How often does home insulation need to be replaced?
- Fibreglass batt and blown-in cellulose can last 20 to 30 years if it stays dry and isn't disturbed, but it settles over time and loses effectiveness, so many older Ontario homes benefit from a top-up well before that. Spray foam holds its R-value longer but should be inspected if you notice ice damming, drafts, or rising heating bills.
- What should I expect during an insulation job?
- A reputable contractor starts with an assessment of your attic, walls, or basement, sometimes with a blower door test to find air leaks. Air sealing comes first, then insulation is added to the target R-value. Attic jobs are usually done in a day; larger wall or basement retrofits can take two to three days depending on access.
- How do I judge the quality of an insulation contractor?
- Look for clear before-and-after documentation (photos or a final depth/coverage report), a written warranty on materials and labour, and proof of WSIB and liability insurance. For spray foam, confirm CUFCA certification. Consistent, detailed customer reviews over several years are a better signal than a handful of five-star ratings from the same month.
Guides to choosing insulation contractor
- Attic ventilation and insulation: why it matters for your roof and energy bills
How attic insulation and ventilation work together to protect a roof from ice damming and moisture, and what signs suggest yours is out of balance.