About 20 percent of Okotoks homes were built before 1991, which means the great majority of the town went up afterwards. Wall spray foam insulation in Okotoks therefore deals mostly with a stock in an awkward middle age: too new for anyone to be gutting it, and old enough that the walls were built before air sealing was treated as its own discipline. That combination decides what is realistic here far more than any product comparison does.
The air barrier and the vapour barrier are two different jobs
A great deal of confusion comes from one sheet of polyethylene being asked to do both. Its vapour job is to slow moisture diffusing through the assembly. The air job is to stop air carrying moisture and heat through gaps, and that only works if the sheet is continuous, sealed at every seam, and unbroken at every electrical box, plumbing penetration and framing junction. In practice it rarely is. A wall can have an intact-looking vapour barrier and no functioning air barrier at all, which is exactly the wall that feels draughty despite being full of insulation.
What foam does that a batt and a sheet cannot
Foam adheres to the cavity surfaces and fills the gaps, so it is the insulation and the air barrier in one operation. There are no seams to tape and nothing that depends on how carefully somebody detailed around an outlet box fifteen years ago. On this stock that is the actual gain, and it is larger than a comparison of R-numbers suggests, because the R-number never described the air leakage in the first place.
Nominal against effective performance
A batt labelled R-20 delivers close to that through the batt and considerably less through each stud, plate and header beside it, because wood conducts heat several times better than insulation. Framing is roughly a fifth of a typical wall area. The label describes a component; the house experiences the assembly, and the two are not the same number.
Why access still governs everything
Foam bonds to the substrate it is sprayed onto, so the cavity has to be open. A finished wall cannot be sprayed regardless of what is promised, and in a town whose houses are mostly recent that is a real limitation, because recent houses are not being opened up. Realistic wall work here rides along with a renovation, a re-side, or a basement being developed. It is worth hearing that before booking a site visit rather than after.
What to do while the walls stay closed
The attic, the rim joist and the crawl space are accessible today, they typically leak more air than the walls do, and they cost less to put right. On a house of this age the rim joist in particular is often the single largest uncontrolled opening in the building. Sending somebody there first is not modesty about the walls, it is the order that returns the most for the money.
Wall Spray Foam Insulation Okotoks: Common Questions
Our house has a vapour barrier already - is that not enough? Not for air. A vapour barrier slows diffusion. Stopping air movement needs a continuous sealed layer, and most walls of this age do not have one.
Is a house from the early 2000s worth upgrading? The walls are usually not the first job unless something is being opened. The rim joist and the attic almost always are.
Can foam be added without removing drywall? No. It bonds to what it is sprayed onto, so the cavity must be open first.
Estimate board feet, then get a free Okotoks quote. More on Wall Spray Foam Insulation Alberta province-wide.
After the foam: the interior finish
Once the foam is in and trimmed, the assembly needs its interior finish, and on an occupied space that finish is also the code-required thermal barrier over the foam. We work alongside drywall finishing in Okotoks, an independent drywall contractor, so the two stages are not left to collide on site.