Crawl Space Spray Foam Insulation Alberta

The vented crawl space was a mistake

For decades crawl spaces were built vented, on the theory that outdoor air would carry moisture away. In an Alberta climate that theory fails twice a year.

In winter, cold outdoor air pours into the crawl space, chills the floor above it and freezes the plumbing that runs through it. In summer, warm humid air enters a cool crawl space and condenses on everything in it - joists, ducts, and the underside of the subfloor.

Meanwhile the stack effect pulls that crawl space air upward into the living space, which is why a musty crawl space becomes a musty house.

Encapsulation is the current standard

The approach that works is to stop treating the crawl space as outdoors and bring it inside the building envelope.

• Seal the vents.
• Closed-cell foam on the perimeter walls, continuous, from the top of the wall down to the footing, and across the rim joist.
• A sealed vapour barrier over the ground, lapped and sealed to the wall foam.
• Leave the floor above uninsulated, because the crawl space is now conditioned space.

The result is a dry, stable, accessible space that is part of the house rather than a source of problems for it.

Insulating the floor above does not work as well

The alternative - batt between the floor joists, crawl space left vented - is common in Alberta and it underperforms consistently.

Batt held up between joists sags, falls, and gets moved by anything that goes down there. It does nothing for the plumbing and ductwork that remain in the cold zone. And it does not stop the crawl space air, which continues to enter the house.

Encapsulation costs more up front and solves the actual problem.

What it fixes upstairs

Homeowners who encapsulate report the same short list: floors that are no longer cold to walk on, the musty smell gone, plumbing that stops freezing, and a furnace that runs less because it is no longer conditioning air that came in through the crawl space vents.

Crawl Space Spray Foam Insulation Alberta: Common Questions

Is a dirt floor a problem? It is the main moisture source. Bare soil evaporates continuously into the crawl space. A sealed ground vapour barrier is not optional in an encapsulation - it is half the job.

What if there is standing water? Fix the water first. Grading, downspouts, weeping tile or a sump, depending on the source. Encapsulating over an active water problem hides it.

Does the space still need ventilation? An encapsulated crawl space is usually connected to the house's conditioned air, typically with a small supply from the HVAC system or a dedicated dehumidifier. It is designed, not left to chance.

Can I still store things down there? Yes, and that is one of the benefits. A dry encapsulated crawl space is usable storage; a vented one destroys whatever is put in it.

Get Crawl Space Spray Foam Insulation Alberta Quoted

Get a free quote with the crawl space dimensions, whether it is vented and whether the floor is soil or concrete. See basements and rim joists.