In a newer town the bonus room means the space over the garage. In Fort Macleod it usually means something older and harder: the finished half-storey under the roof of a storey-and-a-half house. Bonus room spray foam insulation in Fort Macleod is therefore mostly work inside a roof, and the surfaces that make that room uncomfortable are the ones nobody can see.
The shape of the problem
Picture the upstairs of a one-and-a-half storey house. You stand in the middle under full height. The ceiling slopes down on both sides to meet a short vertical wall about three or four feet high — the knee wall. Behind that knee wall, on both sides of the house, is a triangular space running the length of the room, open to the eaves. Above the flat part of the ceiling is a small attic.
So the room is enclosed by five surfaces, not one: the flat ceiling, two slopes, and two knee walls. Behind each knee wall is unheated space that is effectively outdoors. That is the geometry, and it is why these rooms are hot in July and cold in January while the rest of the house is fine.
The knee wall is usually the whole answer
Of those five surfaces, the knee walls are the cheapest to reach and the worst performers as built. They are typically studs with lath and plaster on the room side and nothing at all on the back — no sheathing, no air barrier, just framing facing into a cold triangle that is open to the outside air at the eaves.
Insulation stuffed into that wall from the room side does very little, because there is no barrier behind it and outside air washes straight through. Foam applied from the triangle side onto the back of the knee wall seals and insulates at once, and that is normally the single highest-value item in the room.
The slopes, and whether there is room to do them properly
The sloped ceiling is a rafter cavity, and on an old house the rafters may be only a few inches deep. Filling that cavity completely with closed-cell foam gives real performance in very little depth — roughly R-6 to R-7 per inch — and makes the slope a sealed assembly rather than a ventilated one. That is usually the right call here, because there was never a continuous vent path through those rafters to begin with and the eave below has no intake anyway.
The decision has to be made as a whole, though. Half a sealed slope and half a vented one is the assembly that causes trouble.
The dormer, which is three surfaces of its own
If the room has a dormer, it has cheeks — the small vertical side walls of the dormer — plus its own small roof and its own small ceiling. Dormer cheeks are tiny in area and enormously disproportionate in effect, because they are often the only part of the room with nothing behind them but open roof space.
They are also fiddly to insulate by any method that involves cutting material to size. Sprayed foam is the practical tool there precisely because the shapes are small and irregular.
Do the envelope of the room in one go
The mistake to avoid is treating these surfaces as separate projects. The room is enclosed by a continuous boundary and the comfort comes from making that boundary continuous. Doing the knee walls one year and the slopes three years later means living with the problem in between and paying mobilisation twice.
Foam needs a code-compliant thermal barrier over it in occupied space, and in a finished room that affects how the work is sequenced with the drywall. We quote the job, schedule it and stand behind it.
Bonus Room Spray Foam Insulation Fort Macleod: Common Questions
Why is the upstairs room so much worse than the rest of the house? Because it is enclosed by five surfaces instead of one, and two of them back onto unheated triangles open to the eaves.
What is a knee wall and why does it matter so much? It is the short vertical wall where the sloped ceiling meets the floor. As built it usually has nothing behind it, so outside air washes through whatever insulation is in it.
Can the sloped ceiling be insulated without tearing it out? Sometimes, depending on access from the attic or from behind the knee walls. Where it has to be opened, it is best done as part of a decoration cycle.
How much does bonus room spray foam insulation cost in Fort Macleod? It follows sprayed area and thickness across all five surfaces, plus the covering required in occupied space. Access behind the knee walls is the variable that moves it most.
How do I choose a bonus room spray foam contractor in Fort Macleod? Ask them to list the surfaces enclosing the room. If knee walls and dormer cheeks are not on that list, the quote is for the easy part.
Size the assembly with the R-value calculator, then get a free Fort Macleod quote. More on Bonus Room Spray Foam Insulation Alberta province-wide.