About 72% of homes in Claresholm were built before 1991 — the pre-1991 stock is the core spray-foam retrofit market. Up in the roof that statistic shows up as two things: very little depth at the edge of the ceiling, and a roof that goes through a thaw in the middle of winter whenever the chinook arrives.
There is no room at the eave
The townsite houses here were mostly framed with rafters sitting straight on the top plate, with no raised heel and no truss profile to give any height at the perimeter. Whatever depth exists in the middle of the attic tapers to almost nothing in the last two feet before the soffit, and that last two feet is directly above the exterior wall — the coldest line in the ceiling and the one that governs the edge of the room below.
Blown material cannot solve that, because there is no cavity to blow into. Pile it up at the edge and it blocks the soffit vent; keep it clear of the vent and the taper stays. Sprayed foam is the only product that gives useful R-value in a wedge a few inches deep, because it goes on at R-6 to R-7 an inch when it is closed-cell rather than needing a foot of loose depth to get anywhere.
What a chinook does to a roof
This is the part that is specific to the foothills side of the province, and it is not the same as cold weather. A chinook pushes the air temperature up sharply for a day or two in the middle of winter. Snow on the roof melts, water runs down the slope to the eave, and then the temperature drops back. On a roof where the field of the attic is reasonably insulated but the edge is not, that water freezes where the deck is coldest, which is exactly over the uninsulated perimeter.
Repeat that several times a season and the result is ice at the gutter line, water backing up under the shingles, and staining on the ceiling at the outside wall. Owners usually read it as a shingle problem. It is a heat-at-the-eave problem, and the fix is at the perimeter rather than on the roof covering.
Air out of the house is the other half
Insulation does not stop air movement — air sealing does. The usual holes through a Claresholm ceiling are the attic hatch with nothing on the back of it, the bathroom fan housing, the plumbing stack and the top plates of interior walls, plus the old chimney chase in houses that once had a solid-fuel appliance. Warm wet air leaving through those openings condenses and frosts on the underside of the sheathing, then drips when the chinook warms everything up.
Where foam goes and where it does not
On most of these roofs we seal the penetrations and spray the perimeter wedge, then let blown-in depth do the cheap work across the open field of the attic. That is a deliberately mixed assembly: foam where geometry and air sealing demand it, bulk depth where there is room for it. Spraying the whole flat of an attic to full depth is the most expensive version of a job that does not need doing.
The exception is a storey-and-a-half, which Claresholm has plenty of. There the sloped section between the knee wall and the collar tie has no accessible cavity and no ventilation path worth protecting, and foam against the underside of the deck is usually the only assembly that works.
We take care of the work
You are dealing with the contractor directly on attic spray foam insulation Claresholm. We quote the job, we schedule it, and our own installers do the work.
Attic Spray Foam Insulation Claresholm: Common Questions
Why do we get ice at the eaves in the middle of winter? Because a chinook melts the snow and the water refreezes over the coldest part of the deck, which on this stock is the uninsulated strip above the exterior wall.
Our attic looks full. Why is the outside wall still cold? Depth in the middle of an attic does nothing for the edge. The taper at the eave is where the loss is, and it is a geometry problem rather than a quantity problem.
Do you have to spray the whole attic? Rarely. The perimeter and the penetrations are the work; the open field can take cheaper blown depth on top.
How much does attic spray foam insulation cost in Claresholm? The sprayed portion is priced per board foot and the blown depth is separate, so the number follows area and target R-value. On a storey-and-a-half the sloped section usually sets the scope.
How do I choose an attic spray foam contractor in Claresholm? Ask what they intend to do about the last two feet at the eave. A quote that only addresses the open flat is quoting the easy half.
Size the job with the R-value calculator, then get a free Claresholm quote. More on Attic Spray Foam Insulation Alberta province-wide.