Spray Foam vs. Batt Insulation for Ontario Homes 2026
Both spray foam and batt insulation have strong applications in Ontario renovations. The key is matching the right product to the right location. Here is a practical guide.
Spray Foam at a Glance
Spray polyurethane foam (SPF) expands on application and hardens to fill cavities completely.
Open-cell SPF: R-3.6-3.8 per inch, permeable, lower cost. Good for sound attenuation and air sealing interior cavities.
Closed-cell SPF: R-6.0-7.0 per inch, vapour barrier, structural reinforcement. Best-in-class for below-grade and unvented roof applications.
Key advantage over batt: Eliminates air leakage — which accounts for 25-40% of heat loss in GTA homes.
Use Spray Foam For
- Rim joists: 2 inches of closed-cell = R-12 + complete air seal. Best ROI in any Ontario home.
- Unvented roof assemblies: Required for attic conversions and cathedral ceilings.
- Below-grade basement walls: Moisture-resistant, adheres to concrete.
- Irregular cavities: Fills around pipes, wiring, and blocking.
Use Batt Insulation For
- Standard stud-cavity walls (new construction with separate air sealing)
- Attic floors (blown-in cellulose to R-50-60 is most cost-effective)
- Budget-sensitive projects: 40-70% less cost per R-value vs. spray foam
Health Note
Freshly applied spray foam off-gasses during curing. Vacate building minimum 24 hours after large applications. Use certified installers only.
Cost Comparison
| Product | Cost per sq ft (installed) |
|---|---|
| Open-cell SPF (3.5" cavity) | $1.50-2.50 |
| Closed-cell SPF (2" application) | $2.00-3.50 |
| Fiberglass batt R-20 | $0.80-1.50 |
| Mineral wool batt R-20 | $1.50-2.50 |
| Blown-in cellulose to R-50 | $1.00-2.00 |
Find certified Ontario spray foam and insulation contractors on home.renovation.reviews.
LF Builders uses spray foam in key applications throughout GTA renovation projects. lfbuilders.ca