A good share of Fox Creek's older housing sits over a crawl space rather than a full basement, which is what you would expect on a townsite built quickly. About 75% of homes here were built before 1991, and crawl spaces of that period were built to one assumption: that the space below the floor should be ventilated to the outdoors. In this climate that assumption causes most of the problems we are called about.
Why outdoor vents are the wrong idea here
The reasoning behind a vented crawl space is that outside air will carry moisture away. That holds in a mild climate. In northwest Alberta the outside air in winter is extremely cold and the vents deliver it straight into the space below the floor, so the floor assembly, the ductwork and any water line down there sit in outdoor conditions for months without a thaw. Then in summer the reverse happens: warm humid air enters a space whose ground and walls are still cold, and it condenses on them. The vents make the space wetter in summer and the house colder in winter.
The ground is the moisture source
Under a crawl space with bare soil there is a continuous supply of water vapour rising out of the ground, and in boreal country with a high water table through the spring there can be a lot of it. No amount of insulation in the floor above deals with that, because the problem is a source rather than a temperature. The first thing that happens in a crawl space job is that the ground gets covered with a sealed membrane lapped and sealed up the walls. That step comes before anything is sprayed and it is not optional.
Insulate the walls, not the floor above
The approach that works is to stop treating the crawl space as outdoors and start treating it as part of the house. The vents are closed, the ground is covered, and the insulation goes on the perimeter walls and the rim rather than between the floor joists. Closed-cell foam sprayed to the foundation wall and across the rim joist gives a continuous adhered layer with no gap behind it, carries its own vapour control at about two inches, and brings the water lines and ducts inside the insulated envelope where they belong. Insulating the floor above instead leaves them outside it, which is how pipes freeze in a house that feels warm.
What else is down there
Crawl spaces in houses of this age commonly hold the furnace or the water heater, the main water shut-off and often a sump. Anything with a combustion appliance in it changes the job, because the air supply for that appliance has to be addressed when the space is sealed. That gets confirmed on the site visit rather than assumed, and it is a good reason not to buy a crawl space quote over the phone.
The covering requirement
Exposed foam inside a building needs a thermal barrier over it. A crawl space is still inside the building, and in most cases that means an approved coating over the foam rather than a sheet finish, because nobody is drywalling a crawl space. It is specified up front so the job is finished when we leave rather than left for somebody to discover.
Who does the work
You are dealing with the contractor directly on crawl space spray foam insulation Fox Creek. We quote the job, we schedule it, and our own installers do the work.
Crawl Space Spray Foam Insulation Fox Creek: Common Questions
Should the crawl space vents be closed? In this climate, generally yes, as part of a complete job: ground cover first, then sealed vents, then insulation on the walls.
Why insulate the walls instead of the floor above? Because it brings the pipes and ducts inside the insulated envelope. Insulating the floor leaves them in a cold space.
What about the bare dirt floor? It is a continuous moisture source and it gets covered with a sealed membrane before anything else is done.
How much does crawl space spray foam insulation cost in Fox Creek? It follows the perimeter wall area and the depth, plus the ground membrane and the required covering. Headroom and access affect it, because a tight crawl space is slower to work in.
How do I choose a crawl space spray foam contractor in Fox Creek? Ask whether the ground membrane is in the quote and what they will do about combustion air if an appliance is down there. Those two tell you whether the job has been thought through.
Size the assembly with the R-value calculator, then get a free Fox Creek quote. More on Crawl Space Spray Foam Insulation Alberta province-wide.