DIY Wood Burning Hot Tub

1 / 5
2 / 5
3 / 5
4 / 5
5 / 5
This 5-foot-diameter tub is raised up on 4-by-4 joists so a floor drain could be installed between the tub and the deck.

When we first moved onto our land in September 2015, we had grand plans for immediately building our home. At first, we thought we’d have a basic structure up in just a couple of months, but we quickly realized we weren’t ready to start construction. We decided we might as well find a way to provide long-term comfort for ourselves while tackling a building project that could take years, so we came up with the not-so-crazy idea to set up a wood burning hot tub on our property.

Because we were living off-grid in a 19-foot travel trailer on land without utilities, we wanted to expand our living space into the outdoors and create something to enjoy immediately and remind us why we moved to a remote location. A hot tub satisfies those desires and is a great way to unwind at the end of a long day of work on our property, especially on cold evenings when cabin fever sets in.

We also understood that keeping our bodies in top shape would be a priority because of the hard physical labor of building a house ourselves. We couldn’t take long, hot showers in the travel trailer, and we didn’t even have a clean surface where we could stretch, so we figured the ability to soak in a hot tub would do wonders for our bodies.

First things first: We built a deck for the hot tub. We went straight for a permanent structure and built it on the hillside. Was this challenging to take on as our first large project? Yes. Was it impossible? No. Because we wanted to timber-frame our home using trees from our property, and because we owned an Alaskan Chainsaw Mill, we decided this project would help us get some practice under our belts. We felled a couple of trees and turned them into lumber. Many months later — because winter and other projects quickly halted our progress — we had a beautiful deck on our hillside with a view more epic than we could’ve ever imagined. Plus, 90 percent of the deck consists of materials from our very own property.

Next, we turned our attention to the hot tub. Commercial wood-fired cedar hot tubs cost from $3,000 to $7,000. Aside from wanting to avoid this expense, we really wanted the joy and satisfaction of building our own. We already owned an arsenal of tools, so surely we could use our creativity to build something not only beautiful, but durable. So we studied professionally built cedar hot tubs and tutorials on the web from other DIYers.

Throughout the build, we decided to document every step in what ended up being a 13-part YouTube video series on building a wood-fired cedar hot tub. To see how it all came together, refer to the exploded drawing below. Here’s the build in a nutshell:

Staves. Clear, tight-grain wood is ideal for a hot tub, but it’s often pricey. We used No. 2 cedar because it was locally available at a reasonable cost — but we did have to spend some time cutting out the clear pieces and avoiding knots. Our staves measure 1-1⁄2 inches thick by 3 feet tall by 4 inches wide. The joinery is critical on tub staves, so we used a canoe joint, also known as “bead and cove.” This join allows the staves to act as hinges, so you can easily create the round shape of the tub while keeping it watertight. Our joints were cut with two different router bits. We calculated that we needed 64 staves, so we cut 66 of them, and we ended up using 64-1⁄2. We also cut 11/16-inch-deep dado joints at the bottom of the staves so they would slip onto the perimeter of the floor.

The bead and cove joinery allows the tub staves to act as hinges.

Floor. Our floor was 1-by-6 tongue-and-groove cedar because it’s what we had access to, but we’d recommend that you use 2-by-6s — just be sure they’re free of knots. We used ratchet straps to hold the lumber together while we scribed the circular shape — 5 feet in diameter — and then cut out the circle with a jigsaw. We raised the floor on some 4-by-4s to give us room to install a floor drain between the tub bottom and our deck. We secured the floor pieces together with wood glue.

The authors cut a dado joint into the staves to receive he tub floor.

Plumbing. Our floor drain is a traditional push-button bathtub floor drain that we installed between floor joists. It has an extended elbow joint with a ball valve shut-off to which we attach a garden hose for draining the water.

Bench. We created a bench for the interior perimeter of the hot tub using leftover cedar staves and 2-by-4s. The bench forms four sides of a hexagon; the remaining two sides are missing to make room for the submersible woodstove. We were happy to use wood with knots for the bench. The bench is assembled with stainless steel screws and is screwed to the floor so it won’t float.

Submersible woodstove. We contemplated building our own stove, but were lucky to find a used Snorkel submersible woodstove locally, complete with a chimney pipe, for just $200! The stove is 30 inches wide and about 30 inches high, and it has four matching flanges — two on the back for securing it to the tub (we used 5⁄16-inch stainless steel carriage bolts), and two on the front to hold a fence to keep us from touching the stove and burning ourselves. We built a fence with leftover tongue-and-groove and a couple of braces across the back.

A wooden fence prevents bodies from touching the hot stove.

Assembly. We built our tub upside down and carefully used a mallet to push the stave grooves onto the edges of the floor, taking care not to damage the joints. The staves are held together by three tension cables of 3⁄16-inch vinyl-coated aircraft cable, with the ends connected by a clamp set (a small horseshoe and securing clamps), and a stainless steel turnbuckle to tighten things up.

Cost. Our DIY wood-fired hot tub cost us roughly $700 to build, including the secondhand submersible woodstove.

This 5-foot-diameter tub is raised up on 4-by-4 joists so a floor drain could be installed between the tub and the deck.

Firing It Up

Wood tubs leak like crazy until the wood swells and the tub seals. Because the leakage was outrunning our water supply, we decided to caulk the inside of the tub to give us a head start. Our tub was sealed up and leak-free after a few days, and then we were able to enjoy our first long soak in our DIY hot tub.

The submersible stove heats the water at a rate of about 20 degrees Fahrenheit per hour. It’s possible for the water to get too hot, but it’s not easy to do. We just pay attention, and when the water is close to hot-tubbing temperature, we reduce the amount of wood we load into the stove. Normally, we heat the water to about 100 degrees. Once, we accidentally let it get to about 120 degrees, ruining our chances of soaking for the night.

We created a filter system whereby water is pumped out of the tub, through the filter, and then back into the tub. The filtration system is currently powered by a generator, but will be solar-powered in the future. We also use a biguanide sanitation system (an alternative to chlorine), and change out the water completely every 3 to 4 months.

We’ve been enjoying long dips for two years now, and we haven’t regretted our decision a single day. Not only do we have a place to soak our sore muscles at the end of a hard work day, but this project has allowed us to strengthen both our construction skills and our ability to work together as a couple — something critical to master before taking on our home build. As we begin building our home while living off-grid, we know that we always have the option to retreat to our beautiful hot tub and deck. Even when our property looks like a permanent construction zone, we have a little slice of paradise where we can pop a cold one and enjoy the beauty that surrounds us.

We like that we don’t have to commit to a power bill to heat up the water. We only have to collect some sticks from the forest or find some scrap wood lying around our property. Our wood burning hot tub allows us to take materials that would otherwise be considered waste, and turn them into something of high personal value. We hope this experience will encourage other homesteaders to view a DIY hot tub not as a frivolous luxury, but as an important component that can be built economically.

Finding Affordable Lumber

Clear, tight-grain lumber can be costly. We found a lumber warehouse that buys seconds, and got permission to sort through the lumber to find pieces with sections of clear wood from which we could cut the staves and floor. Sorting isn’t allowed at all lumberyards, so be sure to ask the staff first.

Jesse and Alyssa are building a debt-free timber frame home in the mountains of Idaho. You can follow their journey at Pure Living for Life. All photos courtesy Pure Living for Life.

Need Help? Call 1-800-234-3368