Basement spray foam insulation in Cochrane runs into something that sets this town apart from its neighbours. Cochrane is built on hillsides, and on a hillside the standard house is a walkout. That changes what a basement is.
A walkout is not a basement in the usual sense
In a conventional house the foundation wall is below grade on all four sides, surrounded by ground that stays comparatively steady. In a walkout, one wall is fully above grade and exposed to the weather, another is partly above and partly below, and only the remaining sides behave like a traditional basement. That single wall exposed to the air is doing the job of an exterior wall while being built as a foundation, and it is where the losses concentrate.
The transition line is where the trouble is
The wall that steps from below grade to above grade crosses the frost line partway along its length, which means one section is against stable ground and the next is against outside air. Assemblies rarely change at that point even though the conditions do, and the junction is almost never sealed properly. On a Cochrane walkout it is usually the single coldest line in the house and it runs the full width of the lower level.
Which slope the house sits on changes the answer
Cochrane's topography means two houses of identical construction can behave very differently. One faces the prevailing wind off the hills, the other is sheltered by the slope behind it. One steps down into a south-facing lot that collects sun, the other into a north-facing one that never does. Walking the actual property is worth more here than on flat ground, because the plan does not tell you which of those situations applies.
Doing it before the lower level is finished
A great many Cochrane walkouts have a lower level developed after purchase, which is the moment this work is cheapest and most effective. The wall is bare and completely accessible, and foam applied to the concrete before framing seals the wall itself rather than trying to control air from within a stud cavity. Once a finished wall stands in front of it, the same work costs the demolition and reconstruction as well.
Basement Spray Foam Insulation Cochrane: Common Questions
We have a walkout. Is that different from a normal basement? Substantially. One wall is fully exposed to the weather and another crosses from below grade to above it, so parts of the assembly are doing an exterior wall's job.
Where is the coldest part? Usually the line where the wall steps from below grade to above. Conditions change there and the assembly rarely does.
When should we do it? Before the lower level is finished. Foam to the bare concrete, then frame in front of it, is both cheaper and more effective than working around a finished wall.
Does a walkout wall change the covering? Not the requirement itself. A walkout wall in a Cochrane basement still needs the thermal barrier over the foam wherever the room behind it is lived in.
Size the wall with the R-value calculator, then get a free Cochrane quote. More on Basement Spray Foam Insulation Alberta.
After the foam: the interior finish
Foam is only half of a finished wall. The board, tape and level-5 finish that goes over it is a separate trade, and it is the stage that makes the space usable. We work alongside Emplastrum Drywall, an independent drywall contractor, so the two stages are not left to collide on site.