With about 64% of Drayton Valley homes built before 1991, the rim joist is the most consistently neglected surface in the local housing stock. It is the band of wood that sits on top of the foundation wall and carries the floor above it, and in a house of that vintage it is either bare or has a loose piece of batt leaning against it. Rim joist spray foam insulation in Drayton Valley is the smallest job with the largest effect on how a house feels.
The frost line meets wood at exactly this height
A foundation wall is concrete with soil against it, and the deeper you go the steadier the ground temperature. The rim joist is at the top of that wall, right at grade, which puts it in the band the frost reaches and holds all winter. So the one part of the assembly made of wood, with a floor joist pocket every sixteen inches and a sill plate underneath it, is also the part exposed to the deepest and longest-lasting cold. Nothing else in the house combines that much thermal exposure with that much joinery.
Why it leaks as much as it does
Count the joints. There is the gap between the sill plate and the top of the concrete, which is rarely sealed on a house of this age. There is the joint between the sill and the rim board. There is the seam where the rim meets the subfloor above. There is a pocket at every joist, each with its own set of edges. And then there are the things that were drilled through it later: the gas line, the dryer vent, the electrical service, the hose bib, the deck ledger bolts. In most pre-1991 houses here the rim joist is the single largest collection of unsealed joints in the building, sitting at the coldest exposed height.
What cold air does once it is in
Air entering at the rim joist arrives in the basement ceiling space, which is connected to the floor cavity of the main level. It travels along the joists and emerges wherever it finds a way up, which is why cold floors in a living room so often have their source in a rim joist on the other side of the house. People put rugs down and turn up the furnace. The air keeps coming.
Why a piece of batt does not solve it
Batt is a thermal product. It slows heat and it does not stop air, so a piece of it pushed into a joist pocket lets the air keep moving and now hides the surface it is moving across. Worse, in a long cold season the warm moist house air that gets to that cold rim board through or around the batt condenses on the wood, and the batt holds the water against it. That combination is how a rim joist goes soft, and it is found only when somebody pulls the batt out. Closed-cell foam is applied as a liquid, bonds to the concrete, the sill, the rim and the subfloor in one pass, seals every one of those joints, and at roughly two inches becomes a vapour barrier so indoor moisture never reaches the wood.
It is also the job we can do without taking anything apart
In most houses here the rim joist is visible from the basement or accessible above a dropped ceiling, which means no demolition, no finish to replace and a short job. That is why it is the first thing we recommend on an older house, ahead of attics and well ahead of walls. If a homeowner only does one thing, this is the one with the best ratio of effect to disruption.
Who you are dealing with
Rim joist spray foam insulation Drayton Valley is quoted, scheduled and sprayed by us. Our own installers are on the job, and the number you are given is the number we stand behind.
Rim Joist Spray Foam Insulation Drayton Valley: Common Questions
Why is the floor cold in a room with nothing below it? Because air entering at the rim joist travels along the floor joists and comes up somewhere else. The cold floor and the leak are often at opposite ends of the house.
We already have batt in the joist pockets. Is that enough? No. Batt does not stop air, and in this climate it can hold condensed moisture against the rim board, which is worse than leaving it bare.
Does the work make a mess of a finished basement? Usually not, because the rim joist is often still visible or reachable above a dropped ceiling. We check access before quoting and tell you if anything has to come down.
How much does rim joist spray foam insulation cost in Drayton Valley? It is priced per board foot over the sprayed area, and because the rim joist is a narrow band the quantity is small compared with a wall or an attic. Access is what moves the number: an open basement ceiling is quick, a fully finished one is not.
How do I get a rim joist spray foam insulation quote in Drayton Valley? Tell us whether the basement ceiling is open, and we will look at the sill, the pockets and the penetrations that were drilled through later. We quote it, schedule it and stand behind the work.
Size the job with the R-value calculator, then get a free Drayton Valley quote. More on Rim Joist Spray Foam Insulation Alberta province-wide.