A steel building in Lethbridge has to deal with something most of the province does not: sustained lateral pressure on the envelope, day after day.
Wind finds the laps
Metal buildings are assembled from panels, and panels have laps, eaves, ridge details and fastener penetrations. In still conditions those are minor. Under steady wind they become a driven path.
Air is pushed in on the windward side, through the building, and out the leeward side. It moves past whatever insulation is up there rather than through it, which is why a metal building here can be reasonably insulated on paper and still be uncomfortable and expensive to heat.
Blanket systems are particularly exposed to this. The blanket is not sealed at laps or edges; it is held in place. Wind moving above and around it carries heat away and carries interior moisture to the cold panel.
Closed-cell foam behaves differently because it adheres. There is no gap above it for air to travel in, and the laps and penetrations are sealed by the same pass that insulates them.
The dry-air complication
Southern Alberta air is dry, so the outside climate contributes little moisture. That does not make a steel building here condensation-free - it shifts the source indoors.
Anything that puts water into the air inside the building becomes the whole story: an unvented heater, vehicles bringing snow in, washing, livestock, a wet process. On the days those coincide with a cold deck, moisture goes to the coldest surface it can reach, which is the underside of the steel.
The practical tell is damp that appears on cold mornings and is absent during rain. If the building is dry in a downpour and wet when it is merely cold, the water is coming from inside, and no amount of roof repair will change it.
Wind loading is a structural conversation too
Buildings on open ground here take real lateral load. Closed-cell foam adds stiffness to the assembly it bonds to - that is a genuine secondary benefit and worth knowing, but it is not the reason to buy it and should not be sold as a structural upgrade. If wind loading is a live concern on your building, that is an engineering question, not an insulation one.
Before the quote
- What happens inside - anything adding moisture to the air.
- Continuous or intermittent heating - intermittent is the harder case.
- What is up there now - a failed blanket must be removed before foam, and strip-out plus disposal is the line item most often missing from a low number.
- What has to cover it - see thermal barrier vs ignition barrier.
Why work with us
Alberta's spray foam specialists. Every installer in our network is checked for CAN/ULC-S705 certification, current insurance and WCB standing before they set foot on your property.
No price without a site visit. Get a quote, and tell us how exposed the site is and whether the damp is constant or occasional.
See also metal buildings and stopping condensation in a metal building.