Spray foam insulation is one of the highest-performance insulation options for Ottawa's climate, with R-values per inch that significantly outperform fibreglass batt, mineral wool, or blown-in cellulose. It's also the most expensive insulation on a square-foot basis and the most installation-sensitive — done wrong, spray foam can off-gas, shrink, or fail to bond, leading to expensive remediation. This page covers what spray foam does well, where it makes sense versus alternative insulation, the open-cell vs closed-cell decision, 2026 Ottawa pricing, contractor vetting, and how spray foam inter...
Open-cell spray foam: lower density (~0.5 lb/cu ft), R-3.5 to R-4.0 per inch, vapour-permeable, lower cost ($1.20-$2.00/sq ft per inch in Ottawa 2026). Best for: interior wall sound dampening, attic ceiling under-roof applications, exterior walls in mixed climate above-grade where vapour drive is balanced. Closed-cell spray foam: high density (~2.0 lb/cu ft), R-6 to R-7 per inch, vapour-impermeable (acts as its own air and vapour barrier), structural rigidity (adds shear strength to framing), hi...
Rim joists and band joists: the gap-prone area where the floor system meets the foundation. Closed-cell spray foam here is one of the highest-ROI insulation upgrades in any Ottawa home — typical cost $400-$1,200 per home, energy savings $80-$200/year, eliminates drafts at the basement-floor interface. Pay-back: 3-7 years. Crawl spaces and partial basements: closed-cell spray foam on the underside of the floor joists above (if crawl is unconditioned) or on the foundation walls (if you're encapsul...
Spray foam is not always the right choice. (1) Attic flat retrofits in older homes — typically blown-in cellulose or fibreglass over the ceiling is cheaper and equally effective. (2) Standard new construction walls — fibreglass or mineral wool batts plus a proper air/vapour barrier achieves equivalent R-value at half the cost. (3) Around future-access fixtures, plumbing cleanouts, or electrical splice boxes — spray foam is destructive to remove. (4) When the contractor is not factory-trained on ...
Per square foot per inch of thickness (typical Ottawa 2026): Open-cell: $1.20-$2.00. Closed-cell: $2.50-$4.50. Typical applications: Rim joist closed-cell (200-400 lineal feet typical, 2-3" thickness): $400-$1,200 total. Crawl space encapsulation (300-800 sq ft of foundation wall, 2-3" closed-cell): $1,800-$5,500 total. Basement wall closed-cell (800-1,500 sq ft, 2-3"): $4,800-$15,000 total. Attic ceiling open-cell to underside of roof deck (1,200-2,000 sq ft, 4-6" for R-24 to R-30): $5,000-$18,...
Spray foam insulation qualifies for Canada Greener Homes Grant rebates when it produces measurable energy efficiency improvement: (1) Pre-retrofit EnerGuide evaluation required ($500-$700) by a Registered Energy Advisor. (2) Spray foam application that increases the building envelope insulation value above pre-retrofit. (3) Post-retrofit EnerGuide evaluation ($300-$500) to verify improvement. (4) Rebate paid based on energy efficiency improvement, with maximum $5,000 total grant available across...
Six vetting points: (1) Factory training on the specific product — request training certificate from manufacturer (Demilec, Icynene-Lapolla, Polyurethane Foam Systems, Walltite, etc.). (2) $2M+ general liability insurance with spray foam endorsement (not all liability policies cover spray foam application). (3) WSIB clearance. (4) Active CCMC (Canadian Construction Materials Centre) listing for the product being installed — verify on Natural Resources Canada CCMC registry. (5) Substrate prep pro...
Per square foot per inch: open-cell $1.20-$2.00, closed-cell $2.50-$4.50. Typical projects: rim joist $400-$1,200, crawl space $1,800-$5,500, basement walls $4,800-$15,000, attic ceiling $5,000-$18,000, whole-home wall retrofit $8,000-$25,000. Minimum mobilization typically 1,200-1,500 sq ft.
Open-cell: lower density, R-3.5-4 per inch, vapour-permeable, cheaper. Best for interior walls, attic ceiling under-roof. Closed-cell: high density, R-6-7 per inch, vapour-impermeable (own air and vapour barrier), structural rigidity. Best for rim joists, basement walls, crawl spaces, roof decks.
Highest-ROI applications: rim joists (3-7 year payback), crawl space encapsulation, basement walls, attic conversions to conditioned space, and exterior wall retrofits during renovation. For standard attic flat retrofits or new construction walls, blown-in cellulose or fibreglass/mineral wool batts are usually more cost-effective.
Yes, when paired with pre- and post-retrofit EnerGuide evaluations and measurable energy improvement. Maximum $5,000 total grant across all measures. Typical spray foam rebate components: rim joist $250-$750, attic $1,200-$1,800, basement wall $1,800-$2,500. Loans up to $40,000 interest-free also available.
Verify factory training on the specific product, $2M+ general liability with spray foam endorsement, WSIB clearance, active CCMC listing for the product, substrate prep protocol, and warranty (1-year workmanship, 10-25 year product). Get 3 quotes; expect 30-50% price spread due to mobilization economics.