Crawl space spray foam insulation in Sundre is work on the void under a porch, an addition or an older house built before a full basement was standard. The approach we take is to bring that space inside the building's envelope rather than trying to insulate the floor above it and leave the void outside. In this town there is a particular reason that approach is the right one, and it has to do with what the void sits on.
River gravel does not run out of water
Much of the townsite and most of the acreage development near it sits on terrace material from the Red Deer River: gravel, sand and silt. That ground drains well, which is why building on it is easy, and it also means it stays connected to a water table that moves with the season. A crawl space with a bare floor over that material is not sitting over dry dirt that will eventually dry out. It is sitting over a supply of moisture that is effectively unlimited, replenished every melt and every wet week.
That is why the single most useful thing in a Sundre crawl space is not insulation at all. It is a continuous sheet over the ground, lapped and run up the walls, that stops the soil evaporating into the void. Without it, anything we spray on the walls is enclosing a space that will keep making its own humidity.
Why the vents made it worse
Older crawl spaces here were built with vents in the perimeter on the theory that outside air would carry the damp away. In Alberta's climate that works for part of the year and actively harms for the rest. In July, warm humid outside air comes in through the vents, meets a crawl space that is cool because it is in contact with the ground, and condenses. The vents are then delivering water rather than removing it. In January the same vents are a direct path for cold air to the underside of your floor and to any plumbing running through there.
Closing those vents and sealing the perimeter is what the current approach does, and spray foam is suited to it because the walls down there are rarely flat, square or clean. A sprayed layer bonds to concrete, to block, to a rubble footing and to the irregular joint between the wall and the floor framing, and seals all of them with the same pass.
Seal the perimeter, not the floor above
Insulating the underside of the floor and leaving the void vented is the arrangement that most often disappoints. It leaves the pipes on the cold side, it does nothing about the humidity, and batt installed in a damp space falls down within a few years. Treating the perimeter wall and the band at the top of it instead puts the plumbing inside the heated envelope, puts the insulation on a surface it can bond to, and leaves a floor that is no longer cold because the space under it is part of the house.
Access decides the price more than the area does
Crawl spaces under Sundre additions tend to be shallow, with a hatch cut in a closet floor or an opening through the basement wall. What the quote hinges on is whether a sprayer can physically reach the whole perimeter, and whether anything has to come out first: old batt, fallen vapour barrier, stored material, sometimes decades of it. We will tell you on the first visit if the access means part of the work has to be done differently, and where we are spraying a space that will stay occupied we will cover the ignition barrier requirement at the same time.
Crawl Space Spray Foam Insulation Sundre: Common Questions
Should the vents stay open? No. In this climate they import humidity in summer and cold in winter. Sealing the perimeter and covering the ground is the current approach.
Is the plastic on the ground really necessary? On river terrace ground it is the most important single item. The soil there has access to more water than it can ever dry out.
Floor above or walls around? Walls around, in nearly every case. It puts the pipes on the warm side and gives the foam a surface it can bond to.
How much does crawl space spray foam insulation cost in Sundre? It is priced by the perimeter area and depth plus whatever has to be removed and whatever ground cover is needed, and access is the factor that moves it most.
How do I choose a crawl space spray foam contractor in Sundre? Ask what goes down on the ground and whether the vents are being closed. If neither comes up, the space will still be damp afterwards.
Size the perimeter with the R-value calculator, then get a free Sundre quote. More on Crawl Space Spray Foam Insulation Alberta province-wide.