About 55% of homes in Coaldale were built before 1991, which means nearly half of them went up after it, and in an attic those two groups present completely different problems. On the post-1991 stock we are almost never there to add depth. We are there because of a strip about eighteen inches wide that runs around the whole perimeter of the ceiling.
The heel is where a truss attic runs out of room
A standard roof truss sits on the top of the exterior wall at a height called the heel, and on a house built to the ordinary spec that heel is shallow. The attic insulation is deep in the middle of the span and then tapers as the roof slope comes down to meet the wall plate, until over the wall itself there is only a few inches of room between the ceiling drywall and the underside of the sheathing.
That is the thermal weak point of an otherwise well insulated ceiling, and it is not a defect anybody installed. It is geometry. It shows up as the cold line along the outside wall of an upstairs bedroom, as frost on the ceiling in the corner of a room in February, and as the ice that forms at the eaves when the roof above that strip stays warmer than the rest.
Why blowing more in makes it worse there
The usual response is another pass of blown-in material, and in the middle of the attic that is fine. At the perimeter the extra depth has nowhere to go, so it gets pushed into the ventilation gap at the eave, the soffit vent is blocked, and the attic stops being ventilated at exactly the point where it most needs to be. We find this on houses whose owners paid for a top-up and ended up with worse frost than before.
The right tool at the heel is a sprayed layer applied tight to the top plate and up the underside of the sheathing for a short distance, with the ventilation gap deliberately preserved with a baffle. It is a small volume of foam doing a job no depth of loose material can do in that space.
Wind washing at the eaves
The second thing happening along that same strip is that air entering the soffit vents blows across the top of the loose insulation and through it. Fibrous material is permeable to air by design, so a gentle draught across the surface strips heat from the top inch and reduces its effective value exactly where it is already thinnest. A sprayed layer at the heel stops the air at the perimeter without closing the vent path above it.
The older half of town has a different attic
On a pre-war or post-war house in the old grid there is often no truss attic at all. There is a rafter roof, a ceiling of boards or plaster, an addition with its own small roof space that does not connect to the main one, and whatever was put up there over seventy years. On that stock the first job is finding out how many separate roof spaces there are, because insulating one and not the others produces no measurable change.
Who quotes it and who sprays it
Nobody gets handed your attic spray foam insulation Coaldale job. We quote the job, schedule it and stand behind it, and our crews are the ones who show up.
Attic Spray Foam Insulation Coaldale: Common Questions
There is frost in the corner of the upstairs bedroom. Is the attic empty? Almost certainly not. Over the outside wall the truss heel leaves only a few inches, and that strip is where frost forms on an otherwise well insulated ceiling.
We had the attic topped up and the ice at the eaves got worse. Why? Loose material pushed into the eave gap blocks the soffit vents. The perimeter needs a sealed layer and a preserved vent path, not more depth.
Do we need the whole attic sprayed? On a post-1991 Coaldale house, no. The perimeter strip, the hatch and the ceiling penetrations are the job.
How much does attic spray foam insulation cost in Coaldale? The sprayed portion is priced per board foot over its area and any blown-in depth on top is separate, so a perimeter-only job is a small item. A full attic spray on a house that does not need one is the most expensive version of this work.
How do I choose an attic spray foam contractor in Coaldale? Ask what they intend to do at the eaves. If the answer is only about depth in the middle of the attic, the cold corner you called about will still be cold.
Size the job with the R-value calculator, then get a free Coaldale quote. More on Attic Spray Foam Insulation Alberta province-wide.