What R-value tells you.
R-value describes thermal resistance. A higher R-value means greater resistance to heat flow through the insulation under its rated conditions. The home’s result also depends on coverage, air leakage and the rest of the building enclosure.
Discuss R-50 and R-60.
R-50 is a minimum finished attic target in the current Home Renovation Savings attic rebate tables. R-60 is a higher target that can be discussed for your upgrade. A rebate threshold is not a substitute for assessing the attic or choosing a suitable installation.
| Target | What to discuss |
|---|---|
| R-50 | The starting R-value, total coverage and any applicable rebate route. |
| R-60 | The proposed higher finished level, attic capacity and material requirements. |
| Both | Ceiling air sealing, eave air paths, hatch insulation and exhaust duct connections. |
Inches depend on the product.
Loose-fill fibreglass, batts and other materials do not all provide the same R-value per inch. The manufacturer’s coverage chart and installation instructions guide the depth and quantity. An existing batt layer also affects the additional insulation required.
Ask for a clear specification.
- The existing insulation and its assessed condition.
- The material and proposed finished R-value.
- The area included and the product-specific coverage.
- Preparation, air sealing, baffles and hatch details.
- Any conditions or inaccessible areas that affect the scope.