Under-Slab Insulation
Up until now, it has only been required to provide insulation (at RSI 2.1, or R12) under the concrete slab of a house (either in the basement or at grade) when a radiant-floor heating system is being installed; the intention of this was to limit the amount of heat lost through the floor. As part of the Program, however, we've expanded this requirement such that all concrete slabs must be provided with minimum RSI 2.1 (R12) insulation underneath the slab.
Requiring insulation under all concrete slabs helps to limit heat loss through the floor, of course, but also provides a warmer, more comfortable floor on which to walk and live. Basements that are built on insulated concrete slabs will be more comfortable to occupy for extended periods of time, making it easier to use the floor area for bedrooms, kitchens, even whole separate suites
By-law Language:
Table 9.25.2.1. Minimum Thermal Resistance of Insulation RSI, m² °C/W for Buildings of Residential Occupancy Forming Part of Article 9.25.2.1. |
||
Building Assembly |
Value Required |
|
| Attic Spaces | 7.0 |
|
| Roof Joist Assemblies (Cathedral Ceilings/Flat Roofs) | 4.9 |
|
| Frame Walls (including frame crawl space walls) | 3.85 |
|
| Concrete or Masonry Walls (other than foundation walls) | 2.1 |
|
| Suspended Floors | (Framed) | 4.9 |
| (Concrete Slab) | 2.1 |
|
| Foundation Walls | 3.85 |
|
| Concrete Slabs on Ground at, above, or below grade (insulation under all slab area and around edge of slab) | 2.1 |
|
| Radiant Heating Suspended Floor Assembly Over Heated Area (insulation between heated floor and heated area below) | 2.1 |
|
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