The arch-roofed steel building is usually the oldest steel on a yard, and on a Raymond property it has typically been built into rather than left alone. Quonset spray foam insulation in Raymond is almost always a retrofit on a building that already has a shop room framed inside it, a lean-to hung off one side, and a bigger door cut into one end. Each of those alterations creates the same problem, and it is the reason these buildings drip.
A stud wall inside an arch leaves a wedge
This is the detail that matters most and it is in nearly every one of them. Somebody wanted a square room in a curved building, so they framed a flat wall inside the arch. Between that flat wall and the curving steel is a wedge of space, wide at the bottom and closing to nothing at the top, and that wedge is open to the rest of the building. Warm humid air from the shop gets into it, finds the coldest steel in the building at the top of the curve, and condenses there. The water runs down the inside of the sheet, collects at the bottom of the wedge where it meets the floor, and sits against the base of the stud wall. From inside the room nothing is visible until the bottom plate is soft and the steel behind it is pitted. The fix is to eliminate the wedge by spraying closed-cell foam directly to the arch so there is no cold surface and no air behind the insulation at all.
There is no cavity and no flat surface anywhere
An arch is a continuous curve, so there is no stud bay, no purlin plane and nothing to staple to. Batts have to be held up mechanically against a curve, which is a losing fight, and rigid board has to be cut into tapered strips with a joint every foot. Both leave an air space against cold steel, which is the condition that causes the problem in the first place. Sprayed foam is applied to the curve and sticks to it, and it is the only assembly on this building type that does not depend on a flat surface existing.
Prepare the steel, because adhesion is the whole product
Foam bonds to what it hits. On a building that has been standing for decades that means surface rust, old dust, chaff, grease from equipment and occasionally the remains of a previous insulation attempt. Any of those reduce adhesion, and foam that is not adhered is foam with an air gap behind it, which is where you started. So the preparation is real work: the arch gets cleaned, loose scale comes off, and anything actively corroding gets dealt with before spraying. We would rather tell you that up front than discover it on the day.
The end walls and the base of the arch
The two ends of a quonset are flat walls, usually framed timber, usually containing the doors, and usually in worse condition than the arch because they take the weather and the traffic. They are also where the geometry gets difficult, because the arch meets the flat wall along a curve. Treating the end walls as their own assembly and carrying the sprayed layer across that curved junction is how the building becomes continuous. The base of the arch is the other end of the same problem: the steel runs down to a concrete curb or straight onto a slab, and the joint there is open to the ground. Both get sealed or the rest is decorative.
The lean-to on the side
Where a shed roof has been hung off one flank of the arch, the sheet steel of the arch is now an interior surface for part of its height and an exterior surface above that. The flashing between them is rarely more than a bent sheet. Decide whether the lean-to is inside the heated space or outside it, and seal the junction accordingly. It cannot be both, which is what it currently is.
Quonset Spray Foam Insulation Raymond: Common Questions
Why does the building drip? Indoor moisture condensing on the coldest steel, which on an arch is the top of the curve. It then runs down the inside of the sheet.
We already have a framed room inside. Do we spray the room or the arch? The arch, behind and around the room where it can be reached. The gap between a framed wall and the steel is the cause of the problem.
Does the rust have to be dealt with first? Yes. Foam bonds to the surface it touches, and loose scale means poor adhesion and an air gap where you least want one.
How much does Quonset spray foam insulation cost in Raymond? By sprayed area and thickness. On an arch the sprayed area is considerably larger than the floor area, and preparation of old steel adds time, so both belong in the quote.
How do I choose a Quonset spray foam contractor in Raymond? Ask how they will reach the arch behind the framed room, and what preparation the steel needs. Those two answers separate people who have done arches from people who have not.
Size the assembly with the R-value calculator, then get a free Raymond quote. More on Quonset Spray Foam Insulation Alberta province-wide.