A shop is a building you work in, and that makes it a different problem from a warehouse you store things in. The temperature has to be comfortable for people at floor level, the doors open through the day, and there is usually equipment inside worth protecting.
Intermittent heating is the hard case
Most shops are not heated evenly around the clock. They are warmed for a shift and allowed to drift down afterwards, or heated hard on a weekend and left through the week.
Every warm-up loads the air with moisture - from the heater itself if it is unvented, from vehicles bringing in snow, from wet gear, from anything being washed. When the building cools, that moisture condenses on the coldest surfaces available.
In Edmonton the cooling half of that cycle goes further and lasts longer than it does in southern Alberta, because there is no chinook to interrupt it. The building genuinely gets cold and stays cold between uses, so there is more condensation, and it sits longer before anything dries out.
That is why shops here can develop persistent damp and corrosion even though they are heated regularly.
Corrosion is the real cost
In a shop full of tools, machinery and vehicles, condensation is not a comfort issue - it is a maintenance bill.
Water condensing on a cold steel deck drips onto whatever is below. Surface rust appears on tools and tables. Fasteners and the structure itself take the repeated wet-dry cycling. None of it fails dramatically; it just degrades continuously.
A continuous adhered air and vapour seal against the deck prevents humid interior air reaching cold steel in the first place, which is what stops the cycle rather than managing it. See preventing rust in a steel building and the sweating metal roof fix.
Overhead doors
A shop door is large and gets used. Every cycle dumps the heated air.
Insulation cannot make that not happen, and it is worth being straight about: the achievable goal is a building that recovers quickly and holds temperature between openings. Sealing the envelope is what makes recovery fast, because you are no longer reheating air that immediately leaks away again.
Unvented heaters
If the shop is heated by an unvented combustion heater, the combustion products - including a significant amount of water vapour - go into the room. That is a large moisture source added directly to the air.
Sealing the building without accounting for it moves that moisture into the assemblies. Mention how the shop is heated when you enquire; it genuinely changes what should be specified, and it may mean ventilation needs addressing alongside the insulation.
The covering requirement
Foam in a shop needs an appropriate thermal barrier over it. Get it specified in the quote. See thermal barrier vs ignition barrier.
What we do
We are a referral service. We do not install. We connect you with vetted installers - certification, insurance and WCB standing checked.
No price without a site visit. Get a quote, and tell us how the shop is heated and how often.
See also shop insulation and metal buildings.