Insulation
XPS rigid foam board R-15
Package coverage varies by thickness and framing spacing; enter the package coverage.
Good choice when…
A good candidate when use, exposure, dimensions and every system component match the documentation.
Avoid when…
A poor candidate when compatibility must be improvised, damage hidden or a regulated component replaced without validation.
Reference data
| Purchase unit | sheet |
|---|---|
| Nominal R-value | 15 |
What the numbers mean
- Stated nominal thermal value: R-15; actual installation and continuity determine delivered performance.
Recommended uses
- For the intended assembly, cavity and thermal value after air leaks and moisture sources are addressed.
- To improve comfort and surface temperature where insulation continuity is maintained.
- For work coordinated with ventilation, air barrier, vapour control, heat clearances and future access.
Specific uses linked to this sheet
- Walls in the intended assembly and exposure level.
- Ceilings where thickness, spacing and sag resistance are suitable.
- Attics where ventilation, clearances and moisture control are addressed.
- Basements in an assembly designed for concrete, moisture and condensation.
When to avoid this material
- Do not install over a leak, wet wood, active mould or unresolved drainage problem.
- Avoid compressing, stretching or leaving voids that reduce real performance.
- Do not block soffits, vents, drains, equipment or required clearances.
Compatibility and installation
- Validate air-barrier and vapour-control location for the climate and existing assembly.
- Confirm compatibility with wiring, fixtures, chimneys, ducts and adjacent foams or adhesives.
- Plan inspection before concealment when insulation covers regulated work.
Storage, care and service life
- Keep packages and material dry; do not enclose wet insulation.
- Watch for humidity, condensation, pests and settlement during seasonal inspections.
- Document thickness, R-value, covered areas and concealed work with photos and measurements.
Common mistakes
- Adding insulation without correcting air leakage and moisture paths.
- Relying only on nominal R-value without checking continuity and installation quality.
- Covering boxes, joints, equipment or components that must remain accessible.
Alternatives to compare
- Compare batts, loose fill, rigid boards and foam for access, continuity, moisture, fire and reversibility.
- The best solution may combine air sealing and multiple layers rather than one thicker product.
Before purchase
Confirm exact size, coverage, certification, compatibility, lot and instructions. This sheet helps you ask the right questions; it does not make two similar products equivalent.