Rim joist spray foam insulation in Wetaskiwin is the first thing worth buying on nearly every house in this town, and on a stock this old the detail itself is not the one described on most pages about this subject.
Wood that has been doing this for eighty years
The first question on an old band is not how to seal it, it is whether what is there can be sealed at all. A sill plate that has been in contact with masonry and taking air and water since before the war is frequently sound, occasionally soft at one end, and sometimes carrying damage that nobody has seen because the basement was finished over it in 1975. That gets established with a light and a probe before anything is quoted, because foam bonds faithfully to whatever it is sprayed against and covering soft wood puts a permanent layer over a problem that will keep going underneath it. Carpentry before insulation is a real possibility on this stock rather than a disclaimer.
Cold air enters low and does not leave
It is worth being clear about the mechanism because it explains why so small an area matters so much. Cold air is denser, so it enters at the lowest opening in a building and stays low rather than mixing away, which puts the band at exactly the height where the loss becomes something a household feels rather than something they pay for invisibly. On an old Wetaskiwin house with an unsealed band, that is the draught at ankle level in the room people actually sit in, and it is why sealing a few inches of joint changes the experience of a room far more than the numbers suggest it should.
Why it outperforms almost anything else here
The band is a few inches tall and easy to dismiss on that basis. What makes it count on an old house is that it is a set of joints rather than a cavity, in a stock where nothing was ever sealed, at the lowest point of the building where cold air enters and stays. It takes an afternoon where a basement is unfinished, it needs no demolition, and it produces a change at the perimeter of the rooms above that a household actually feels. On a Wetaskiwin house it is consistently the item that returns the most per dollar on the list.
Reaching it, and what to do if the basement is finished
Where the basement is open it is visible and reachable in a day. Where it was finished at some point in the last forty years it sits behind a stud wall and a poly sheet, and on this stock that finish is frequently old enough to be coming out for other reasons anyway. Doing the band at the same time as any basement work is the cheapest route by a long way, and where nothing is planned the honest advice is usually to wait for the renovation that will open it.
Rim Joist Spray Foam Insulation Wetaskiwin: Common Questions
Is there more than one band on our house? On anything with an addition, yes. Two or three is normal on this stock.
Can spray foam go over an old sill plate? It gets checked before anything covers it. Not every one of them is sound enough to spray.
Can a finished basement still be insulated? Then do it with whatever opens that wall next, rather than as a job of its own.
Size the assembly with the R-value calculator, then get a free Wetaskiwin quote. More on Rim Joist Spray Foam Insulation Alberta.