Insulation Contractor in Ontario
Insulation work covers attic top-ups, wall cavity insulation in older homes, spray foam in basements and rim joists, and vapour barrier or air sealing done alongside any of that. It's often paired with roofing jobs, since a re-roof is the easiest time to fix poor attic ventilation or add baffles before new insulation goes down, and a bad insulation job can shorten the life of a roof by trapping moisture where it shouldn't be. We track 822 insulation contractors across Ontario, from small crews doing attic blow-in to larger outfits running spray foam rigs and doing full basement or new-construction packages.
What to check before you hire
Ask what material they're proposing (cellulose, fiberglass batt, blown fiberglass, open-cell or closed-cell spray foam) and why, since the right choice depends on the space, not just the price per square foot. Confirm they'll address air sealing first, not just piling insulation over gaps, and that they know Ontario Building Code minimums for your area's climate zone. For spray foam specifically, ask about applicator certification (CUFCA is the recognized body) and whether they carry proper liability coverage, since a bad spray foam job is expensive to fix. Get a written scope that lists R-value targets, square footage, and whether old insulation is being removed or topped up.
How we score contractors
Our ranked guide to insulation contractors in Ontario weighs verified licensing and insurance, real customer feedback, how long a company has been operating, and how responsive they are to quotes and follow-up work. The full scoring breakdown is on our methodology page if you want to see exactly how businesses move up or down the list.
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All insulation contractor, ranked by score and relevance
We found 1322 businesses offering insulation contractor; 44 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.
Enquiries you submit through our forms may be shared with partner providers who can carry out the work, and we may receive a referral fee. Our rankings and scores are based only on our published methodology and are not influenced by referral fees.
Common questions about insulation contractor
- How much does attic insulation cost in Ontario?
- A basic attic top-up (blown cellulose or fiberglass) typically runs a few hundred to around $1,500-$2,500 for an average detached home, depending on square footage and how much old insulation needs removing. Spray foam costs considerably more per square foot than blown-in material, so a full attic or basement spray foam job can run several thousand dollars.
- How often does insulation need to be replaced?
- Fiberglass and cellulose can settle and lose effectiveness over 15-20 years, and older homes (pre-1980s) are often under-insulated by current code. Signs it's time include ice damming on the roof, uneven room temperatures, high heating bills, or visible thin/compressed insulation in the attic.
- What should I expect during an insulation job?
- A reputable contractor will inspect the space first, check for existing air leaks and moisture issues, and give a written quote specifying material, R-value, and coverage area before starting. Most attic jobs take half a day to a full day; spray foam jobs may take longer due to curing and ventilation requirements.
- How can I tell if the insulation work was done well?
- Check for even coverage with no thin or missing spots, proper baffles at the eaves so soffit vents aren't blocked, and confirmation the contractor sealed obvious air leaks (around pot lights, plumbing stacks, attic hatches) before insulating over them. Ask for photos of the completed work if you can't access the attic yourself.
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.