Moisture Resistant

Due to its non-porous nature, medium-density spray foam insulation resists moisture penetration. By comparison, conventional fibreglass batt insulation is susceptible to moisture infiltration, which can drastically reduce its R-value and contribute to mould accumulation. When applied below grade, medium-density spray foam can eliminate the problem of damp or wet basement walls.

Managing Vapour, Not Just Water

Warm indoor air carries moisture. When it reaches a cold surface inside a wall or attic, that moisture condenses, and over time that causes mould, rot and failed insulation. Closed-cell spray foam applied at sufficient thickness acts as its own vapour retarder, keeping the dew point inside the foam rather than on a cold structural surface.

• Closed-cell foam resists water absorption
• Acts as a vapour retarder at adequate thickness
• Does not lose R-value when exposed to damp
• Will not support mould growth as a food source
• Bonds to the substrate, leaving no gap for air to reach

Why This Matters Below Grade

Basement and crawl space walls are the classic failure point. Batt insulation held against a cold foundation wall lets warm indoor air reach the concrete, where it condenses behind the insulation out of sight. Foam bonded directly to the wall removes that air gap entirely, which is why it is the standard recommendation for below-grade applications in our climate.

One Thing It Will Not Fix

Spray foam manages vapour, not liquid water. If a foundation is actively leaking, or there is a drainage or grading problem outside, that has to be corrected first. We will tell you if we see it rather than covering it up.