Building an Outdoor Sauna

[Robin]

I am planning a sauna for my backyard and was trying to get a couple of questions answered.

First of all, does it have to be on a concrete base? I was thinking that if I mounted the building on concrete pads I could insulate under the floor. Then I would just have a tile floor on top of that.

Next, Western Red Cedar or Finnish Spruce? Saw this question before but no answer. The Finnish spruce would be cheaper.

Any thoughts or suggestions would be appreciated.

Robin

[Wolf Lahti]

Duckboards over concrete are traditional and make the sauna easy to clean. I've never seen a sauna with a tile floor, but I don't see any reason why that wouldn't work. One source says that ceramic tile is the best floor, followed by heavy-duty seamless vinyl (?) and sealed concrete. Me, I'd just go for inexpensive and easily maintained lightly brushed concrete. Whatever floor you use, raise the edges so that water won't rot the lower edges of your paneling.

In the US, most softwoods will work for walls: Alaskan Yellow Cedar, Western Redcedar, Western Redwood, Aspen, Idaho White Pine, Western Hemlock, Sugar Pine, Eastern White Pine, Eastern White Cedar....The interior of the traditional Finnish sauna is Northern White Spruce, but benches made of spruce will get too hot to sit on. For them, Obechi (Abachi--sometimes misspelt as Apache) is the material of choice for those that have larger wallets than I do. Aspen is said to do well - pine, hemlock, and fir are okay if you can guarantee there are no knots or pockets of pitch. Use only the highest grades if you do use them.

I like Western Redcedar for most everything - it's light, dimensionally stable, and easily worked - but everyone else seems to like it too; it's gotten really pricey in the past few years. Some people like redwood for benches, but in my opinion it is far too prone to splintering for such use.

Misc: All wiring should rated to at least 90 deg. C. Have no exposed screw or nail heads. Make benches removable for ease of cleaning. Learn how to make and use a vihta. Drink homemade sima after sauna. Use your avanto. :)

[J T]

Wed, Jun 23, 2004, 8:22pm (EDT-3) [e-mail] (Robin) wants to know: does it have to be on a concrete base?

If it doe, then those Finns been doint it wrong all those centuries.

Then I would just have a tile floor on top of that.

Hmmm, sauna, tile floor, yep, that should be the perfect way to do in that pesky mother-in-law, first time she uses it. Your defense can always be, "I didn't know a tile floor would be slick".

JOAT Use your brain - it's the small things that count.

- Bazooka Joe

[Robin]

Thanks for the info - guess when I said tile I meant as something to keep the moisture from the wood. Figured the duckboard on top of the tile was something that didn't need to be said....

[Grandpa]

An Aunt & Uncle used to have one, concrete floor, cedar T&G vertically & cedar siding horizonally over that & had cedar benches etc. Same basic wood you'd use on a fence, not the expensive fancy cedar. For heat they used a steel canister, 20/25gal or so boxed in & surrounded by river rock. If you wanted steam, pour a little water on the rocks. The heat source was wood. Fire was built & maintained thru a small access door on the outside. Chimney up thru the roof. Worked great, & cheaper than gas etc. I suppose you could adapt a propane tank to this too of necessary.

Grandpa

Rob> I am planning a sauna for my backyard and was trying to get a couple

[J T]

Thu, Jun 24, 2004, 8:53am (EDT-3) [e-mail] (Robin) says: Figured the duckboard on top of the tile was something that didn't need to be said....

Now you know better.

Nobody knows what you know, or what you're planning, until you say. Best to put in as many details as you can think of.

Like if you've allready spend days looking on the web, and haven't found what you're looking for. Otherwise, your first response is probably going to be, google.

JOAT Use your brain - it's the small things that count.

- Bazooka Joe

[Dave W]

I built an outdoor sauna two years ago. It is accessed from the deck by a short bridge. It is high enough that I got a storage room under the sauna. I insulated the floor but am going to remove the insulation because the local critters enjoy pulling it down. Floor insulation is probably not needed since the floor in a sauna stays pretty cool. I used local Eastern White Cedar for the inside surfaces, all tongue and groove on the walls. For the floor, I used slate in the entry room and fiberglassed plywood in the sauna room pitched to a central drain to get rid of water. Duck boards are cedar also. Wall construction (from outside to inside) is: one inch vertical pine with battens on the seams, six inch spruce studs with 6 inches of fiberglas insulation, plastic film to insure keeping moisture out of the insulation, 3/4 inch strapping on the studs to create an air space, 3/4 inch Cedar t&g. The t&g stops just short of the ceiling and about 4 inches off the floor to insure air ventilation behind the t&g. Ceiling has same construction as walls. Two levels of benches and a real Finnish sauna stove complete the picture. If you have questions, I will be pleased to help or send photos. Dave

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[Rudy Lang]

I don't know if tiles outside are a good idea. Any expansion or contraction of your sub-floor and the tiles will crack like crazy. Of course, I have no idea of your climate. Perhaps others here can confirm or refute my concerns.