A DIY wood-fired hot tub needs three things: a tub that holds hot water, a wood-burning heater, and a solid, level base. Most home builds use a stock tank (plastic or galvanized steel) or a cedar tub built from staves. The heater is either an internal "snorkel" stove that sits in the water or an external heater or copper coil that circulates the water through the fire. Buy a purpose-built heater rather than welding your own, plan a cover, and expect to change the water about weekly. If you would rather skip the build, a finished wood-fired tub such as our Starlight comes ready to fill.
This guide compares the build options, walks through the steps, and shows when a finished tub is the better choice.
DIY wood-fired hot tub options at a glance
| Build | Tub | Heater | Skill level |
|---|---|---|---|
| Stock tank with coil | Galvanized steel or plastic stock tank | Copper or stainless coil in an outside fire | Moderate |
| Stock tank with snorkel stove | Stock tank | Purpose-built stove that sits in the water | Moderate |
| Cedar stave tub | Cedar staves, joined and banded | Snorkel stove or external heater | High: precise joinery |
| Finished tub | Built by the maker | Built in | Set it on a base and fill it |
Step 1: Choose the tub
According to The Cover Guy, many DIY builders use stock tanks made for cattle water, in plastic or galvanized steel. A narrow tank suits one person and heats faster with less water; a round tank suits a group. One well-known video build by HomeMadeModern used a 169-gallon galvanized stock tank.
For a high-end look, you can build the tub from cedar. Cedar swells as it soaks up water, which seals the joints, and it weathers well. However, a stave tub needs careful joinery; the Instructables cedar hot tub walks through it in nine steps, from sourcing clear cedar to cutting and joining the staves.
Step 2: Choose the heater
- Internal snorkel stove. A sealed firebox sits in the water, with an opening at the top for wood and smoke. The whole firebox transfers heat to the water, so The Cover Guy calls it the most efficient option.
- External heater or coil. Water runs from the tub through pipes heated by the fire and back again. Built correctly, it circulates by convection without a pump, but it heats more slowly. The HomeMadeModern build used 20 feet of 1/2-inch copper tubing as a coil.
The Cover Guy recommends buying a heater built for wood-fired tubs rather than building your own firebox, unless you are a qualified welder. We agree: a wood fire next to people in water is not the place to experiment.
Step 3: Build a solid base
Water weighs about 8.3 pounds per gallon, so a 170-gallon tub carries roughly 1,400 pounds of water before anyone gets in. Set it on a level concrete pad or compacted base. Keep the fire side clear of decks, overhangs and anything that burns, and follow the heater maker's clearances.
Step 4: Fill, fire and soak
Fill the tub with a hose, light the fire, and stir the water now and then so the heat spreads. Heat-up time depends on the water volume, the starting temperature and the weather. For what to expect, read how long wood-fired hot tubs take to heat and stay hot.
Step 5: Cover and change the water
A cover keeps the heat in and the leaves out. Most wood-fired tubs run without filters or chemicals, so the water is changed instead. The Cover Guy says that with daily use you can expect to drain and refill about weekly.
Safety basics
- Never leave a fire burning unattended, and keep children away from the stove and chimney.
- Check the water temperature before you get in, and stir first, because the water near the heater gets hotter.
- Keep the chimney and heater clear of the soaking area.
- Check local burn rules and permits for outdoor fires.
What does a DIY wood-fired hot tub cost?
It ranges widely with materials and how much you reuse. Field Mag documented a stylish build with reclaimed wood for about $2,300. A stock tank with a coil can cost less, while a cedar stave tub with a store-bought stove can cost more. Add the cover, base and firewood. For the costs of a finished tub, including firewood and upkeep, read wood-fired hot tub cost.
Source: Field Mag.
DIY or a finished wood-fired tub?
| DIY build | Starlight Wood Burning Hot Tub | |
|---|---|---|
| Heater | You buy and fit it | Internal wood stove, built in |
| Water | Depends on your tub | 233 US gallons |
| Heat-up | Depends on tub and heater | Under 3 hours to soaking temperature, varying with water temperature and weather |
| Look | Tank or self-built wood | White cedar skirting that matches the Canadian Timber saunas |
| Base | Your design | Level base, at least 44 x 84 inches |
| Warranty | None | 5-year residential limited manufacturer warranty |
| Price | Depends on materials | $5,505 (white plastic liner) or $7,423.50 (aluminum liner) |
The Starlight is handcrafted in Ontario, needs no electrical connection, and ships free as curbside freight in the lower 48. Browse the wood-fired hot tub collection, or compare heat sources in electric vs wood-fired hot tub.
DIY wood-fired hot tub: FAQ
What is the best tub for a DIY wood-fired hot tub?
A stock tank is the easiest start. Cedar looks better and seals itself as it swells, but it needs precise woodworking.
Snorkel stove or external coil?
A snorkel stove sits in the water and heats more directly. An external heater or coil keeps the fire outside the tub but heats more slowly.
Do I need a pump?
Not necessarily. A well-built external system can circulate by convection, and a snorkel stove needs no circulation at all.
Do wood-fired hot tubs need chemicals?
Many owners skip filters and chemicals and change the water instead, about weekly with daily use, according to The Cover Guy.
Can I add a cold plunge next to it?
Yes, many owners alternate hot and cold. See our DIY cold plunge guide or the cedar cold plunge tubs.
Questions about the Starlight?
Ask us about siting, the base or winter use before you order: call +1 (307) 309-8328.