Crawl space spray foam insulation in Devon is rarely a whole-house job. The original townsite houses were built with full basements, so when we get a crawl space call here it is almost always about something attached to the house later: a rear porch, a mudroom, an enclosed back entry, a family room addition or a sunroom built out over a shallow perimeter wall or a set of piers.
Additions are where the cold rooms are
Those additions share a pattern. They were built years or decades after the house, by whoever was available, to whatever standard seemed sufficient at the time, and they were not tied into the original foundation. The floor sits over outdoor air or over bare ground, the perimeter wall is short and often uninsulated, and the junction where the addition meets the original house is a gap nobody ever closed. That is why the back room of a Devon house is routinely the coldest room in it despite being the newest.
Vented, when it should not be
The older thinking was to vent a crawl space year round, on the logic that moving air dries it out. Under a heated room in central Alberta that logic fails twice over. In winter the vents deliver outdoor air directly under a floor people walk on, so the floor is cold no matter what is stapled between the joists. In summer warm humid air entering a cool crawl space condenses on the cool surfaces inside it, adding water rather than removing it.
Seal it and bring it inside
The approach that works is to stop treating the crawl space as outdoors. Closed-cell foam on the perimeter wall and across the rim, a sealed ground cover over the soil, the vents closed, and the space conditioned at a low level so it tracks the house. The floor above then has house-temperature air under it rather than January air, and the ground moisture is cut off from the wood.
Where the floor gets insulated instead
Sometimes the perimeter route is not available — a floor over open piers, or a crawl space too shallow to work in. Then the underside of the floor becomes the insulated plane, sprayed into the joist bays and sealed at the perimeter and around any pipes passing through. The thing that must not happen is insulating the floor while leaving plumbing in the unconditioned space below it. On a Devon winter night that is a frozen line.
Ground moisture is the quiet problem
An uncovered dirt floor evaporates water continuously, and that water ends up in the joists and subfloor above it. Musty air in the room upstairs, cupping floorboards and a smell that comes and goes with the weather all trace back to it. A sealed ground cover is not an upgrade; it is part of the job.
The valley side of town
Properties toward the river valley sit lower and closer to the water table, and cold air drains into the valley bottom on still nights. Crawl spaces on those lots run damper and colder than the same construction on the plateau, and they are worth looking at before any interior finishing goes in above them.
Crawl Space Spray Foam Insulation Devon: Common Questions
Should the vents be closed? Under a heated room, yes, as part of a sealed and insulated assembly. Closing vents and changing nothing else is the one version that can make things worse.
Why is the back addition the coldest room? Because it sits over a shallow uninsulated perimeter or over open air, and the joint where it meets the original house was never sealed.
Do we insulate the walls or the floor above? The walls where the space can be sealed and conditioned, which is the better outcome. The floor above where it cannot — and then any plumbing down there has to be dealt with.
How much does crawl space spray foam insulation cost in Devon? Priced per board foot sprayed, so the perimeter or floor area and the thickness set it. Headroom is the Devon variable; a space you cannot sit up in costs more in labour than in material.
How do I choose a crawl space contractor in Devon? Ask what happens to the dirt floor and what happens to the vents. A quote that only mentions insulation has left out half the assembly.
Size the assembly with the R-value calculator, then get a free Devon quote. More on Crawl Space Spray Foam Insulation Alberta.