Medicine Hat has the oldest housing stock of Alberta's tier-one cities: about 61 percent of homes here were built before 1991. It is also one of the sunniest and driest places in the country, which produces a wide daily temperature swing that most of the province does not see to the same degree. Both of those facts point at the same material, for different reasons. Closed cell spray foam insulation in Medicine Hat is retrofit work on assemblies that never had a vapour barrier.
An old stock argument
A house built before 1991 was built to a different air-sealing expectation than one built today, and the difference is not something you can add later with more insulation on top. Closed-cell foam is the retrofit material that addresses the leak rather than the R-value, because at a continuous depth sealed at the edges it counts as part of the building's air barrier under Alberta section 9.25 and becomes a vapour retarder at roughly 38 mm. In practice that means one product doing the work that a batt and a polyethylene sheet were supposed to do together, in assemblies where making poly airtight was never realistic.
The swing is what wears an assembly out
Big daily temperature ranges mean the assembly is being pushed one direction by day and the other by night, every day. That cycling is what finds unsealed joints. It is also why long-term thermal resistance is worth asking about: foam is rated on the R-value it is expected to hold over time rather than the one it starts at, and in an assembly that never stops moving that distinction is not academic.
Attics, and the number people actually want
The common target is R-38 in the attic, which is roughly six inches of closed-cell. That is not always the right way to spend the money - air-sealing the ceiling plane with foam at the penetrations and topping up with a cheaper material is frequently the better value, and an honest quote will say so. Where closed-cell is the answer without qualification is below grade, on exposed floors and rim joists, and in cavities too shallow to reach the target any other way. Older established areas like Crescent Heights, Ross Glen, Norwood and Terrace tend to throw up the shallow-cavity version of this problem more often than the newer south-end neighbourhoods do.
Commercial and industrial
Brier Park and the Southeast Industrial area carry the steel buildings where the failure is condensation on a cold panel rather than heat loss through it. Foam bonded directly to the metal removes the surface the moisture was condensing on, which is a different specification from a residential job and is priced differently.
Compliance
Material to CAN/ULC-S705.1, installed to CAN/ULC-S705.2 by a certified installer, with a thermal barrier - 12.7 mm drywall or an approved intumescent coating - anywhere the foam faces occupied space. Attics and crawl spaces reached only for service can use an ignition barrier.
Closed-Cell Spray Foam Insulation Medicine Hat: Common Questions
Is it worth it on housing this old? About 61 percent of local homes predate 1991 - the oldest tier-one stock in the province - and those assemblies never had a functioning vapour control layer.
Does the dry climate change the case? Not below grade. The air is dry; the ground is not. Against a foundation wall the material still has to resist moisture.
How thick for a basement? Roughly two inches gives R-12 to R-14, and three to four inches reaches R-18 to R-28 where the cavity allows it.
Size it with the spray foam calculator, then get a free Medicine Hat quote. More on closed-cell foam province-wide.