Quonset spray foam insulation in Sundre is sprayed directly onto the inside of the corrugated arch. It is the only insulation approach that suits the shape, because there is no cavity, no flat plane and nothing to fasten a board to. On the yards around this town the arch is usually one of the older buildings standing, and two things about how it sits here decide what the job is.
Most of them still have an earth or gravel floor
A great many arch buildings on properties around Sundre were never given a slab. The floor is packed gravel or bare ground, and on the river terrace material common here that ground stays in contact with moisture through most of the year. An arch building with a bare floor is therefore evaporating water into itself continuously. In summer that is invisible. In winter it goes to the underside of the steel and comes back as frost, then as drips when a warm spell arrives.
This is why insulating an arch sometimes disappoints. If the ground is the source and nothing is done about it, sealing the shell gives the water fewer places to go. The sequence that works is to deal with the floor first, with a slab or at minimum a lapped ground cover over the whole footprint, and then spray the arch. We would rather tell an owner that before quoting than be blamed for it afterwards.
The snow does not slide off an arch here
An arch is supposed to shed snow. The snow that comes up against the slopes west of here is wet and heavy, and it does not behave like dry prairie snow. It bonds to the corrugation rather than sliding, builds on the shallow upper curve, and banks deep against both sides where the arch meets the ground. That bank at the base holds the bottom of the sheet wet well into spring, which is where arch buildings corrode first, and the retained snow on the upper curve keeps the steel cold for long stretches.
Nothing we spray changes the snow. What it changes is whether the inside face of that cold steel is a condensing surface. Closed-cell applied to the inside of the arch puts the dew point inside the foam, and because it bonds continuously to the corrugation there is no air gap behind it for moisture to travel in.
The corrugation is the reason foam is the only option
Every attempt to insulate an arch with something cut to size runs into the same wall. The sheet is a series of curved ribs and valleys. A board touches the ribs and leaves a void in every valley, and those voids become continuous channels running the full length of the building, carrying humid air from one end to the other and depositing it on cold steel the whole way. Batt stuffed into them compresses at the ribs and falls out of the valleys. Sprayed foam follows the profile exactly, which is the whole reason this application exists.
The end walls are a different building
The arch is steel. The end walls are usually framed timber with cladding, often added later, often the leakiest part of the structure, and they almost always have the big door in them. Treating the arch and leaving the ends is a half job. The ends get framed-wall treatment, and the junction between the end wall and the arch needs to be sprayed as one continuous detail rather than two jobs meeting.
Quonset Spray Foam Insulation Sundre: Common Questions
Why does my Quonset frost up inside? Because warm moist air reaches the cold steel. On a building with a bare floor the ground is usually the main moisture source.
Does the floor really have to be done first? If it is bare ground, yes. Sealing the shell over an open moisture source moves the problem rather than solving it.
Can boards or batt be used instead? Not well. The corrugation leaves continuous voids behind anything flat, and those voids become the path the moisture travels in.
How much does Quonset spray foam insulation cost in Sundre? It is priced by the sprayed area of the arch and the end walls at the depth needed, so the span and the length drive it. Floor work is a separate item and belongs in the plan first.
How do I choose a Quonset spray foam contractor in Sundre? Ask what they intend to do about the floor and the end walls. A quote covering only the arch has priced the part that is easy to measure.
Size the arch with the R-value calculator, then get a free Sundre quote. More on Quonset Spray Foam Insulation Alberta province-wide.