Rim joist spray foam insulation in Strathmore is the first thing worth buying on most houses here, and on an open lot it matters more than the same detail would in a sheltered town.
The band the wind finds first
On a Strathmore lot the rim sits at the point where the wooden structure meets the foundation, a few inches tall, with framing joints running in three directions at once. On any site that is the busiest junction in the building. On an exposed one it is also the place the pressure difference across the building is resolved, so air is not seeping through it, it is being pushed through it whenever the wind blows. That is why the same band leaks measurably more here than the identical detail on a sheltered street in a treed town.
An inspection passed, and nothing was sealed
The batt in each bay is there because somebody was required to put insulation at the rim and did exactly that. It was inspected, it was signed off, and it was entirely correct against what was being asked for. What was not being asked for at the time was continuity of the air barrier across a junction where three framing members meet, and no amount of material pushed into a bay achieves it. That distinction is why a household can be told in good faith that the area is already insulated and still have a cold perimeter, and it is worth understanding rather than treating as somebody having cut a corner.
Nobody tells you the window is closing
From possession until somebody frames the basement, the entire band is open, visible and reachable in a day with no demolition and nothing to make good. After that it sits behind a stud wall, a membrane and drywall. What makes this worth stating is that nothing marks the transition: the household books a basement development for reasons that have nothing to do with insulation, the framing goes up on a Tuesday, and an item that was an afternoon's work becomes a job that involves taking a finished room apart. A great many houses in this town are inside that window right now and the households in them have no idea it is one.
What people report afterwards
The change is not usually an energy bill, it is the perimeter of the rooms above. Floors that were cold along the outside walls stop being cold. A draught at ankle level in the room people actually use goes away. And on an exposed lot the house stops feeling different depending on which way the wind is blowing, which is the thing owners here mention most and the thing they least expect a few inches of foam to change.
Rim Joist Spray Foam Insulation Strathmore: Common Questions
What if the bays already have insulation in them? Batt does nothing about air, and the rim is a set of joints rather than a cavity.
Is it worth doing on its own? It gives more back per dollar than anything else in most houses here, particularly on an open lot.
Can a finished basement still be insulated? Then it is behind the wall, and the honest advice is usually to wait until something opens it.
Size the assembly with the R-value calculator, then get a free Strathmore quote. More on Rim Joist Spray Foam Insulation Alberta.