Frequently Asked Questions
What R-value is required for attic insulation in Ontario?
Ontario's Building Code requires R-60 for attic insulation in Zone 6, which includes all of Renfrew County. This applies to both new construction and major renovations where attic access is available. Older homes that have not undergone major renovations are not required to upgrade, but doing so is highly recommended for energy savings.
How much does attic insulation cost in Renfrew County?
Blown-in attic insulation in Renfrew County typically ranges from $1.50 to $3.00 per square foot, depending on depth and material. A full 1,000-square-foot attic to R-60 runs approximately $1,500 to $4,000 including labour and air sealing. Spray foam attic insulation costs significantly more, ranging from $3.00 to $5.00 per board foot for closed-cell foam.
What is spray foam insulation and when should it be used?
Spray foam is a two-component polyurethane foam that expands on application to create an air-sealing insulation layer. Closed-cell spray foam offers R-6 to R-7 per inch and also acts as a vapour barrier. Open-cell spray foam offers R-3.5 to R-4 per inch and requires a separate vapour barrier. Common applications in Renfrew County include rim joists, crawlspaces, attic hatches, and unvented roof assemblies.
Do I need a permit for insulation work in Ontario?
A building permit is typically required for new insulation installation in Ontario when it is part of a larger renovation. Adding blown-in insulation to an existing attic that does not alter the structure may not require a permit, but it's best to check with your local Renfrew County municipal building department. Spray foam application in occupied spaces may require permits and must be done by certified applicators.
What is a vapour barrier and is it required in Ontario?
A vapour barrier is a polyethylene sheet installed on the warm side of insulation to prevent moisture-laden indoor air from reaching the insulation and condensing. Under the Ontario Building Code, vapour barriers are required in Zone 6, which includes all of Renfrew County. The standard material is 6-mil polyethylene with all seams taped and sealed around penetrations.
How do I know if my current insulation is adequate?
Check your attic insulation depth — in Renfrew County, you need approximately 22–24 inches of blown-in insulation to reach R-60. Other signs include uneven indoor temperatures, high heating bills, ice dams on your roof in winter, drafty rooms, and cold floors over unheated spaces. A professional energy audit with a blower door test can provide definitive answers.
What causes ice dams and can insulation prevent them?
Ice dams form when heat escaping through a poorly insulated attic melts snow on the roof, which then refreezes at the colder eaves. The resulting ice buildup can force water under shingles, causing roof leaks and interior damage. Proper attic insulation (R-60) combined with adequate ventilation is the most effective long-term solution. Air sealing attic penetrations is equally important to stop warm air leakage into the attic space.
Blown-in vs batt insulation for Renfrew County attics — which is better?
Blown-in insulation (cellulose or fibreglass) is generally preferred for Renfrew County attics because it fills irregular spaces around joists, trusses, and obstructions more completely than batts. Blown-in cellulose offers better air-sealing properties than fibreglass batts. However, fibreglass batts are easier to install as a DIY project and may be more appropriate for open attics with standard joist spacing. Both can achieve R-60 when installed to the correct depth.
Can I insulate my own attic in Ontario?
Yes, you can insulate your own attic in Ontario. DIY installation of fibreglass batts or blown-in insulation from big-box stores is feasible for straightforward attics. However, proper air sealing is critical — sealing all penetrations, recessed lights, and attic hatches requires careful work. Spray foam must be applied by certified professionals. Safety precautions include wearing a respirator, eye protection, gloves, and ensuring electrical wiring is not buried under insulation.
What is thermal bridging and how does it affect my home?
Thermal bridging occurs when heat travels through conductive building materials like wood studs or metal fasteners, bypassing the insulation between them. In a standard 2×6 wall, the studs themselves account for approximately 25% of the wall area and have an R-value of only R-6.5. This significantly reduces the effective R-value of the wall assembly. Solutions include exterior continuous insulation, insulated sheathing, or spray foam filling the entire stud cavity.
How long does spray foam insulation last?
Properly installed spray foam insulation has a lifespan of 30 years or more. Closed-cell spray foam is particularly durable because it does not settle, compress, or degrade over time when protected from UV light and physical damage. The material's closed-cell structure also resists moisture absorption, which helps maintain its R-value. Many manufacturers offer 20-year to lifetime warranties on their spray foam products.
What is SB-12 in Ontario?
SB-12 is a supplementary standard to the Ontario Building Code that was adopted in 2017. It provides enhanced energy efficiency requirements beyond the base building code, focused on higher R-values, improved air tightness, and reduced thermal bridging. While SB-12 applies primarily to new construction in larger municipalities, its principles are relevant to any Renfrew County homeowner planning a deep energy retrofit. The standard can serve as an excellent benchmark even where not legally required.
