How to build a sauna that’s suitable for Canadian winters


In the depths of winter, is there anything better than finding somewhere really warm to relax? It’s no wonder that in Finland—which is farther north than most of the heavily populated areas of Canada—having a sauna is as necessary as having a refrigerator. Take some hints from the Finns when building your own year-round cottage sauna.

Inside or outside?

Traditionally, a sauna is separate from the main building, usually in close proximity to water or, at least, somewhere you can roll around in the snow (cooling off is part of the experience—trust us). Depending on where you’re building, you may need to make sure you’re allowed to have a sauna on your property, so check with your township or municipality. If you build inside, remember that a sauna creates A LOT of extra humidity, so it requires careful venting and moisture control. (This isn’t the case for infrared saunas, but they tend to be on the pricey side.)

Materials (and what you do with them) are important

The traditional wood for saunas is cedar, although there’s some question about cedar’s safety in terms of volatile organic compounds that are released when the wood heats up. And while cedar is highly insulating, both in terms of temperature and sound, it also absorbs more moisture than other woods, causing discolouration and, potentially, mould. Northern white pine or aspen are good alternatives—but if budget is a question, you can build a successful sauna using scrounged materials. Make very sure that nailheads that may come into contact with bare skin are covered or counter-sunk—no one likes burning hot metal on their delicate bits. Benches should also be knot-free, because knots also get extremely hot.

Insulate carefully

Standard insulation may out-gas harmful chemicals in the hot atmosphere of a sauna, so consider using eco-friendly recycled cotton insulation or, as Mike Holmes suggests, Roxul. If you install a vapour barrier, it should be made of foil, rather than plastic.

Decide on your fuel

If you’re building at the cottage, it may not be practical (or possible) to have a gas- or electricity-fired sauna stove, which leaves you with good, old-fashioned wood. Regardless of fuel, you’ll need air circulation, whether to provide a source of oxygen for your fire, or simply to supply fresh air.

Tell us about your experiences with cottage saunas in the comments. Worth it? Not worth it? What would you recommend?