Shipping container spray foam insulation in Claresholm is a small but steady part of the work. Containers turn up on dryland farm yards, on acreages, behind highway businesses and on the industrial lots at the edge of town, and they get used for things their original design never anticipated.
What they are actually used for here
Three uses dominate locally. Secure storage for tools and small equipment on a yard with no shop space. Seed, chemical and parts storage where a dry, lockable building is needed and there is no room in the shed. And occasionally a site office or a lunch and warm-up room on a job.
Those three want different things. Tool storage wants no condensation on steel. Seed and chemical want dry above all else. A warm-up room wants to come up to temperature in twenty minutes and hold it. The same box insulated for one of those is wrong for another, so the use has to be settled before the specification.
A container has no thermal mass and that is the whole problem
A building has a floor, a structure and contents that store heat. A container is a thin corrugated steel shell with a timber deck and nothing else. It responds to the outside almost immediately.
In a chinook belt that means the inside of a container tracks the swing with very little lag. The temperature in there can rise thirty degrees through an afternoon and fall back overnight, every time the weather moves. Each cycle pushes the steel through the dew point of whatever air is inside, so water forms on the ceiling and the walls, runs down, and collects on the deck. Containers are notorious for this and it is why unlined ones wreck what is stored in them.
Direct sun makes it worse in both directions. A dark steel box in full sun gets far hotter than the air, and a container on an open yard here has no shade at all.
Closed cell sprayed to the steel is the only sensible assembly
The corrugated profile has no flat surface, no cavity and no framing. Anything cut to size has to be furred off the steel, which creates a gap, and a gap between warm air and cold steel is a condensation site by definition.
Closed-cell foam adhered directly to the inside of the corrugations fills the profile, bonds to the metal, and at roughly two inches is its own vapour barrier. There is no cavity left for air to get behind, so the condensing surface simply stops existing. At R-6 to R-7 an inch it also gets useful resistance into a depth that does not eat the inside dimensions, which matters in a box eight feet wide.
Preparation, the deck and the doors
Three practical points. The steel has to be clean and dry for the foam to bond, and most used containers have surface rust and residue inside. The timber deck is usually treated and is the one surface people leave bare — it is in contact with the ground frame and it is worth insulating. And the doors are a permanent gap: the original gaskets are made to keep weather out of a sealed box in transit, not to seal a heated room, and on a container being used as a warm-up space the door perimeter is the largest remaining leak.
We spray the inside rather than the outside. Foam exposed to sunlight degrades, so an exterior application needs a protective coating over it and that is a different and more expensive job.
Shipping Container Spray Foam Insulation Claresholm: Common Questions
Why does it rain inside our container? Because the steel has no mass and follows the weather. Every chinook swing takes it through the dew point of the air inside, and the water forms on the ceiling.
Can it be insulated on the outside? It can, but foam has to be protected from sunlight, so that means a coating over it. Inside is normally the better answer.
Does the floor need doing? If it is being used as a room, yes. The deck sits on the steel frame in contact with the ground and it is usually the coldest surface you stand on.
How much does shipping container spray foam insulation cost in Claresholm? Priced per board foot of sprayed surface, so a container is a small, predictable area. Cleaning the steel first and any required covering over the foam are separate items.
How do I choose a shipping container spray foam contractor in Claresholm? Ask what they will do about the doors and the floor, and whether they want to know what the container is for. The use changes the depth and the finish.
Size the assembly with the R-value calculator, then get a free Claresholm quote. More on Shipping Container Spray Foam Insulation Alberta province-wide.