R‑Value Explained: What It Means and What Is Required in Ontario
Understanding the Science Behind Insulation Performance
Whether you’re insulating a home, commercial space, or industrial building, R‑Value is one of the most important concepts to understand. At SprayFoam Greenland Inc., we want to help you make informed decisions that improve energy efficiency, comfort, and long-term value.
What Is R‑Value?
R‑Value is a measurement of thermal resistance — or how well a material resists the flow of heat. The higher the R‑Value, the greater the insulating power.
It’s measured per inch of thickness, and different materials offer different R‑Values:
| Material | R‑Value per Inch |
|---|---|
| 2 lb Closed-Cell Spray Foam | R‑6.0 to R‑6.5 |
| Fibreglass Batt Insulation | R‑3.2 to R‑3.8 |
| Open-Cell Spray Foam | R‑3.5 to R‑4.0 |
| Cellulose (Blow-in) | R‑3.5 to R‑3.7 |
| Mineral Wool | R‑3.7 to R‑4.2 |
Why R‑Value Matters for Your Home or Project
A higher R‑Value helps:
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Keep warm air inside during winter and outside during summer
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Reduce energy bills by minimizing heating and cooling loss
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Prevent drafts, cold spots, and condensation issues
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Meet or exceed Ontario Building Code energy efficiency standards
Ontario Building Code – Minimum R‑Values (Zone 6)
In Ontario’s Climate Zone 6, the Ontario Building Code (OBC) outlines minimum R‑Values required for various building assemblies:
| Application Area | Minimum R‑Value Required |
|---|---|
| Attic / Roof | R‑50 to R‑60 |
| Walls (Above Grade) | R‑22 to R‑24 |
| Basement Walls | R‑12 to R‑20 |
| Floors Over Unheated Areas | R‑31 to R‑35 |
Note: Requirements may vary for new builds, renovations, or under Ontario’s Energy Efficiency Tiered Standards.
Reference: Ontario Building Code – Supplementary Standard SB-12 (PDF)
Additional Info: Ontario Regulation 332/12 (Building Code Act)
How Spray Foam Helps You Meet Code — and Go Beyond
Our 2 lb Closed-Cell Spray Foam delivers one of the highest R‑Values per inch of any insulation on the market — typically R‑6 to R‑6.5 per inch.
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To reach R‑60, only 6 to 8 inches of spray foam is required
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Functions as an air, vapour, and moisture barrier in one seamless layer
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Reduces framing and labour costs compared to batt + vapour barrier installations
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Ideal for roof decks, vaulted ceilings, basements, and energy retrofits
Recommended R‑Value Applications With Closed-Cell Foam
| Application | Target R‑Value | Typical Thickness (Closed-Cell Foam) |
|---|---|---|
| Roof / Ceiling | R‑55 to R‑60 | 6″ to 10″ |
| Exterior Walls | R‑24 | 4″ |
| Basement Walls | R‑20 | 3.5″ |
| Garage Ceilings | R‑31 | 5″ |
Want to Know What You Need?
Our team can assess your property, calculate the ideal R‑Value, and recommend the best insulation strategy based on your goals and budget.
Whether you're aiming to meet the minimum building code, apply for energy rebates, or build a net-zero ready home — we’ve got you covered.
Contact Us for a Free Consultation
Email: sprayfoamgreenland@gmail.com
Website: www.sprayfoamgreenland.ca
