About 45% of homes in Slave Lake were built before 1991. That is the retrofit market, and it is worth being specific about what a house from that period actually is, because the work follows the construction rather than the complaint.
What a 1970s or 1980s house here is made of
Two-by-four or two-by-six walls with fibreglass batt between the studs. A polyethylene sheet stapled over the inside face, which was the vapour strategy of the era and which only works where it is continuous, and it is never continuous around an electrical box. A truss roof with blown material over the ceiling and no attention paid to the holes through it. A floor system resting on a concrete wall with nothing sealing the joint. Every one of those details was normal practice. Together they make a house that holds temperature poorly in a winter that lasts five months.
The thing that actually goes wrong
Fibreglass slows heat moving through a material. It does nothing to stop air moving around it, and it is air movement that empties a northern house. Warm air rises, finds the openings in the ceiling plane and leaves; cold air is pulled in low through the rim joist and the basement to replace it. The owner feels a cold floor and a draught, assumes there is not enough insulation, adds more on top of the ceiling, and feels very little difference. The insulation was not the problem.
Where the house gives up first
The joint where the floor meets the foundation is the biggest leak you can reach without opening anything. The ceiling penetrations come next, meaning the plumbing stack, the bathroom fans, the pot lights and the top plates where interior walls meet the ceiling. Then any floor with outdoors underneath it, which here means the cantilevered bay and the room over the garage. Those three groups account for most of the loss in most houses of this age in this town.
Where the lake comes into it
The open water next to town gives wind a long clear run before it reaches a wall, and sustained wind changes the behaviour of every one of those leaks. A still-air gap is a slow exchange. Under pressure it becomes a driven path, with air pushed in on the windward face and drawn out of the leeward one all day. It also pushes dry snow into soffits and around window flanges, where it melts later and gets mistaken for a plumbing or roofing fault.
What foam does in a house like this
Closed-cell goes where there is a cold surface and a moisture risk: against concrete, at the rim joist, under a cantilever, inside a knee wall. It adheres, so there is no gap behind it for air to circulate in, and at adequate depth it keeps the dew point inside the foam. Open-cell is the interior material, for sound between rooms and for cavities with no moisture exposure. Most Slave Lake houses need a combination, and the honest answer on a lot of them is that two or three targeted areas will outperform doing everything.
Residential Spray Foam Insulation Slave Lake: Common Questions
We added attic insulation and the house is still draughty. Why? Because depth does not stop air and your ceiling is still open. The new material sits above the leaks rather than closing them.
Can you spray our existing walls without tearing them out? Closed walls can be injected, but it is a different product and a different result from an open-cavity spray. We will tell you honestly whether it is worth doing on your wall.
Should the old poly come out? Sometimes, and that is a site decision rather than a rule. Two vapour-control layers with a gap between them is the assembly that causes trouble.
How much does residential spray foam insulation cost in Slave Lake? Board feet, meaning area times depth, plus whatever has to be removed to reach the surface. On a house of this age the removal is often the bigger half.
Who does residential spray foam insulation in Slave Lake? We do. We quote the job, schedule it and stand behind it, and we would rather do two areas properly than the whole house thinly.
Size the job with the R-value calculator, then get a free Slave Lake quote. More on Residential Spray Foam Insulation Alberta province-wide.