Rim joist spray foam insulation around Nisku is work in the basements of the older houses on the Leduc County land near the park, and it comes with a complication that does not apply on newer stock. On a house built in the last few decades the rim joist is a continuous band of lumber running around the top of the foundation wall, and insulating it is a tidy, repeatable job. On the farmhouses here, that band frequently does not exist. The floor joists are set into pockets in a masonry wall instead, and that changes the job from one long detail into a row of individual ones.
Pockets, not a band
Walk the perimeter of one of these basements with a light and you can see it: the joists come in through the wall, each sitting on a bearing surface with mortar or packing around it and an air gap above and beside it. There is no rim board closing the row off from the outside. Each pocket is a separate opening through the wall, and there may be dozens of them. Some will have been parged, some will have rags or bits of board stuffed in, and some will be open enough to feel the wind on a cold day. That is the condition the work has to deal with.
Each pocket is its own hole
Because the pockets are independent, the leakage is not one long path that can be addressed with one long piece of anything. It is many small, irregular, unequal openings in series along the wall. Cut insulation cannot seal them, caulk cannot bridge them and a plastic sheet cannot be made to follow them. A sprayed product can, because it goes into each pocket, around the joist and onto the masonry in one application, and it cures as a single continuous layer across all of them. It is the clearest case in a house of this type for using spray instead of anything else.
Check for rot before you bury it
A joist end sitting in masonry has been in contact with a cold, sometimes damp surface for the whole life of the building. Some of them will be sound and some will not. Every pocket gets probed before it is sprayed, because foam over a soft joist end hides a structural question rather than answering it. Where there is decay, that gets repaired or sistered first by someone whose job it is. This is the reason we open and look rather than quoting this work off a photograph.
Sill plates that sit on nothing flat
Where there is a plate on top of the wall, it is usually sitting on an uneven masonry surface with a gap under it that varies along its length. Mortar beds settle, stone is not flat and nobody levelled anything in the first place. That gap is continuous and it is directly connected to the outside. Spraying across the top of the wall, over the plate and into the pocket row seals all three conditions, the pockets, the plate gap and the first few inches of the wall, at once.
Where it sits in the running order
First, almost always. It is the smallest quantity of material in any job we do on these houses and it addresses the biggest proportionate leak, because the bottom of a building is where cold air is being drawn in to replace what is leaving the top. Owners who do only this item and nothing else still report that the main floor is warmer and the floors are less cold underfoot. It also rarely interferes with anything else, so there is no reason to wait for a larger project.
We take care of the work
Rim joist spray foam insulation Nisku gets handled by us from the walk-through onward. We quote and manage it, and our own installers apply the foam.
Rim Joist Spray Foam Insulation Nisku: Common Questions
My basement does not seem to have a rim joist. What is there instead? On an older farmhouse the joists are usually set into pockets in the masonry wall. There is no continuous rim board, so there are many small openings rather than one long one.
Why can it not be done with batts or caulk? Because the openings are irregular, unequal and recessed. Cut material cannot seal them and caulk cannot bridge them, which is exactly what a sprayed application is for.
Is it safe to spray over the joist ends? Only after each one has been checked. A joist end bearing in masonry can be decayed, and foam over it hides the problem instead of fixing it.
How much does rim joist spray foam insulation cost in Nisku? It is priced per board foot for the area sprayed, and the total area here is small, which is why this item returns more per dollar than anything else in the building. Any repair found in a pocket is separate work.
How do I choose a rim joist spray foam contractor in Nisku? Ask whether they will check the joist ends first. On a masonry foundation that is the difference between a sealed basement and a buried problem.
Size the assembly with the R-value calculator, then get a free Nisku quote. More on Rim Joist Spray Foam Insulation Alberta.