This comprehensive guide compares spray foam vs blown-in insulation options specifically for Ottawa homeowners, with local pricing, climate considerations, and practical recommendations based on Ottawa's unique conditions. Whether you are planning a renovation, building new, or maintaining your home, understanding these options helps you make the best decision for your specific situation, budget, and priorities. Ottawa's extreme climate, diverse housing stock, and active renovation market make this comparison particularly relevant for local homeowners.
Blown-in cellulose costs $1.50 to $2.50 per square foot for attics. Spray foam costs $2.50 to $5.00 per square foot per inch.
Blown-in cellulose is the most affordable insulation option for attics. A 1,200 square foot attic upgrade from R-20 to R-60 costs $1,800 to $3,000. Blown-in fiberglass costs slightly more at $2.00 to $3.00 per square foot. Dense-packed cellulose for walls costs $2.00 to $3.50 per square foot. The lo...
Closed-cell spray foam costs $2.50 to $5.00 per square foot per inch of thickness. Two inches on basement walls costs $5.00 to $10.00 per square foot. Open-cell foam costs $1.00 to $2.00 per square foot per inch but lacks moisture barrier properties. A typical basement perimeter with 2 inches of clo...
Each type excels in different applications.
Closed-cell spray foam provides R-6 to R-7 per inch — the highest R-value per inch of any common insulation. Blown-in cellulose provides R-3.2 to R-3.8 per inch. This means spray foam achieves higher R-values in thinner applications, important for space-constrained areas like basement walls and rim ...
Closed-cell spray foam provides both insulation and a moisture/vapour barrier in one application. This is particularly valuable in Ottawa basements where moisture management is critical. Blown-in insulation does not provide air sealing or moisture barrier — it must be combined with separate air seal...
The best insulation choice depends on where it is being installed.
For attic insulation, blown-in cellulose is typically the best choice for Ottawa homes. It is cost-effective, fills irregular spaces well, can be installed over existing insulation, and achieves high R-values inexpensively. Getting from R-20 to the recommended R-60 is most affordable with blown-in. ...
For basement walls, closed-cell spray foam is superior in Ottawa. It provides insulation and moisture barrier in one application, adheres directly to concrete walls, and prevents the condensation issues that plague batt insulation in basements. Two inches of closed-cell foam (R-12 to R-14) meets cod...
For rim joists, spray foam is the clear winner — it seals and insulates in one application. For existing wall cavities, dense-packed cellulose is typically more practical and cost-effective. For new construction walls, the choice depends on budget and overall building envelope strategy.
Both materials have environmental implications worth considering.
Cellulose is made from recycled newspaper with borate fire retardant — it has a lower embodied energy than spray foam. Spray foam (both open and closed cell) uses chemical blowing agents and has higher embodied energy. However, both materials reduce operational energy consumption significantly, and ...
For basements and rim joists in Ottawa, yes — the moisture barrier and air sealing properties justify the premium. For attics, blown-in cellulose provides excellent performance at lower cost.
Blown-in cellulose is the best value for most Ottawa attics. It achieves R-60 cost-effectively at $1,800 to $3,000 for a typical 1,200 sq ft attic.
Closed-cell spray foam is best for basement walls in Ottawa. It provides insulation and moisture barrier in one application, preventing condensation and mold issues.
Yes, and it is often the best approach. Use spray foam for basements, rim joists, and critical air sealing areas, and blown-in cellulose for the attic. This optimizes both cost and performance.
Spray foam may off-gas during and shortly after installation. Professional installation with proper ventilation is essential. Once fully cured (24 to 72 hours), spray foam is stable and inert.