If the picture in your head is winter, two kids in pyjamas with damp hair, steam coming off a tub in the backyard and a fire crackling next to it, you're in the right place. An off-grid wood fired hot tub is the version of a hot tub that doesn't need power, doesn't need plumbing, and doesn't need a tradie to get it running. You fill it from the garden hose, you light a fire, and a couple of hours later you're in.
This is the full guide. What they cost in Australia, how they actually work, what wood to burn, where to put one, and what the first night is going to look like. Written by the Perth team that imports them.
Alt: Terra Tanks Off-Grid Wood Fired Hot Tub installed outdoors in an Australian backyard
Why a wood-fired tub, and why off-grid
Most hot tubs sold in Australia are spa pools. They run on a 15 amp or 32 amp circuit, they need a sparky to commission them, and the electricity bill to keep one warm through a Perth winter is not small. They look great in the brochure. The reality is a $12,000 to $25,000 unit plus an electrician plus a heater that runs almost constantly.
A wood fired hot tub does the same job a different way. The water sits in a sealed steel tub. A wood-fired heater, usually a coil-style stove that sits beside the tub or a snorkel inside the tub, warms the water by convection. No power, no plumbing, no permit on a tub this size. You buy the wood at the servo or split your own from a fallen jarrah branch. The fire is part of the experience, not a problem to design around.
"Off-grid" here means exactly what it sounds like. The tub does not need to be connected to anything. No electrical circuit, no gas line, no inlet plumbing past a garden hose. That changes what's possible for the household. A rental, a small block where the meter box is on the wrong side of the house, a holiday property at the back of a paddock, a backyard where the bank balance is there but the appetite for trenching isn't. All of those are good candidates for the off-grid version.
For the right household, this is the simplest path to a real soak you can do all winter, and it stays useful through summer too if you keep the water cool and treat it as a plunge.
What an off-grid wood fired hot tub actually is
The Terra Tanks Off-Grid Wood Fired Hot Tub is a 1.8 metre oval galvanised steel tub with a wood-fired coil kit, an insulated cover, and a paddle. The tank itself is the same galvanised steel used on Aussie rural water tanks. Coating is G90 zinc on pre-galvanised carbon steel, the same spec that keeps a water tank doing its job for fifteen to twenty-five years.
Dimensions: 1.8 m long, 0.61 m wide, 0.61 m deep. Holds enough water to seat two adults comfortably with their shoulders under, with room for a third if you don't mind the squeeze. Empty weight is light enough to be carried in by two people. Filled weight sits around 660 kilograms once you add bodies, which is well within the limits of a paver pad or a small slab.
The coil kit is a marine-grade stainless steel coil that drops into the tub and connects via two short hoses to an external wood-fired stove. The stove sits on a non-combustible base next to the tub, usually a paver or two. As the fire burns, the water in the coil heats up, rises, and circulates back into the tub by natural convection. There's no pump, no power, no thermostat. The fire is the thermostat.
What you get in the Terra Tanks Off-Grid Wood Fired Hot Tub box:
- The 1.8 m oval galvanised steel tub
- The off-grid wood-fired coil kit (stove, coil, chimney, connecting hoses, fittings)
- An insulated cover
- A timber paddle for stirring during heat-up
- Setup and care instructions
The coil kit is also available separately for $950 if you already own a compatible tub (or want to convert a Cold Plunge Tub & Outdoor Bath into a hot tub later). More on that decision near the end of this guide.
The trampoline family angle: why this is landing with parents
We sell to acreage owners, weekend cabin builders, athletes, and the occasional eccentric. The household most surprised by how much they use it is a more boring-sounding one: two parents, kids under ten, a suburban block, a backyard that's mostly lawn and a trampoline.
Someone shows the others a video of a family in damp pyjamas around a steaming tub on a winter night. The kids vote yes. The parents do the maths on a real spa pool, look at the install bill, and quietly close the tab. Then they find this. A Terra Tanks Off-Grid Wood Fired Hot Tub fits in the corner where the trampoline used to be. It costs less than a weekend away in Margaret River. It runs without a power point. The kids learn to time a fire. The parents get a Saturday night with a glass of wine and water that's actually warm.
We're not going to pretend wood firing is for everyone. If you want a button you press at 4pm and a tub that's ready at 7pm without thinking about it, an electric tub is the answer. If you want the soak, the fire, the smell of jarrah smoke, and a price that doesn't make you flinch, this is the answer.
What an off-grid wood fired hot tub costs in Australia
Here's the real number, with nothing hidden. The tub is the smallest part of the spend. The pad and the firewood are where the rest goes.
The tub, fully equipped:
- Off-Grid Wood Fired Hot Tub (1.8 m oval): $2,495. Tub, coil kit, stove, chimney, hoses, paddle, insulated cover, setup guide.
Delivery:
- Free to Perth and Sydney metro
- Flat $395 to regional WA and regional NSW
- $595 to QLD, VIC, SA and TAS metro
- Quote-based for NT, remote, and far north
Site preparation:
The tub needs a stable, flat, non-combustible base. Three realistic options.
Compacted cracker dust or sand pad (DIY). Roughly a 2.5 m by 1.5 m area, 70 to 100 mm deep. Cracker dust in Perth runs around $60 to $80 per cubic metre, you'll want about 0.3 of a cubic metre, materials are $20 to $40. Add delivery and a plate compactor hire for the day ($60 to $100). Total: around $150 to $250.
Pavers over a compacted base. The most common Terra Tanks install. Pavers from Bunnings or a local supplier cost $30 to $80 per square metre, you'll want around 4 square metres for the tub plus the stove pad. Installed yourself with a basic sand-and-paver method: $300 to $600. Installed by a landscaper: $600 to $1,200.
Concrete slab. A small residential slab works perfectly and looks the most finished. Roughly $80 to $150 per square metre installed. For a 4 to 5 square metre pad: $500 to $1,000.
Firewood, for the season:
A good winter of weekly soaks burns through somewhere between half a cubic metre and a cubic metre of seasoned hardwood. In Perth, a delivered cubic metre of jarrah sits around $400 to $550 at the time of writing in 2026. On the east coast, ironbark and spotted gum sit at similar numbers. If you split your own from fallen wood on the property, it's free time rather than cash.
All-in cost examples (real, not best-case):
Off-Grid Wood Fired Hot Tub, DIY paver pad on an existing flat patch of yard, half a cubic metre of jarrah for the season: roughly $2,900 to $3,300 all-in for the first winter.
Off-Grid Wood Fired Hot Tub, landscaper-installed paver pad, full cubic metre of premium hardwood: roughly $3,500 to $4,200 all-in for the first winter.
Compared to a $15,000 plug-in spa pool plus an electrician plus the running electricity, even the more polished version of an off-grid wood-fired setup is a fraction of the alternative. And there are no power bills attached.
Setting it up: where the tub can go
The tub needs three things in its location: a stable, non-combustible base; clearance for the stove and chimney; and enough sky above it that the smoke goes up and away from doors and windows.
Approved bases for the tub:
- Compacted cracker dust, pavers over a compacted sub-base, or a concrete slab.
- The base needs to hold the filled weight (around 660 kilograms) and stay level within plus or minus 5 millimetres across the tub's footprint.
- A freestanding deck next to the tub is fine. The tub does not sit on timber. The stove never sits on timber. Both stay on a non-combustible base of their own.
Bases to avoid:
- Lawn, bare earth, soft ground, or any surface that flexes under load.
- Any timber deck, board, or trex surface. Heat from the stove can ignite or warp timber even at distance.
- Sloped or uneven ground that you haven't levelled. An out-of-level tub puts uneven load on the seam between the base and the sidewall.
Clearances:
- At least 1 metre clear on every side of the stove. The chimney and the stove body get extremely hot during firing and skin contact causes immediate, serious burns.
- At least 1.5 metres clear above the chimney top from any eave, awning, tree branch, or shade sail.
- Set the tub well clear of windows, dryer vents, and air-conditioner intakes. Smoke and a hot tub are both lovely outside and unpleasant inside.
Smoke and neighbours. Wood-fired tubs produce smoke during the first twenty minutes while the fire establishes. After that, a clean fire of seasoned hardwood produces very little visible smoke. If your block sits close to neighbours and you're firing regularly, talk to them. Most people are fine with a hot tub fire on a Saturday evening, fewer are fine with a smoky Sunday morning when they're trying to put washing on the line.
Wind. Breezy sites are fine for the soak, but wind changes how the stove draws. Expect to use slightly more wood and watch for embers from the chimney. The supplied chimney cap helps. Keep a hose or a bucket of water within reach during firing.
The full installation guidance is in the setup instructions that ship with every tub. Read it once before you light a fire.
Lighting the first fire, step by step
The order matters. Get this wrong and you can damage the heater on day one.
Step 1: fill the tub. Run a standard garden hose into the tub until water sits at least 100 mm above the top of the coil's inlet fitting. Roughly half an hour from a standard Aussie hose. The tub holds enough water that the coil is fully submerged from below. Do not skip this step. The coil and the heater need water around them to dissipate the heat the fire produces. A dry fire will warp the coil and can destroy it permanently.
Step 2: open the connecting hose valves. The two short hoses that link the coil to the external stove need their valves open so water can circulate. Both valves stay open through the entire firing process.
Step 3: lay the fire. A small handful of kindling, a fire starter or a few sheets of newspaper, and three or four small splits of seasoned hardwood. Use the same technique you'd use for a small bonfire in a fire pit.
Step 4: light it and close the stove door. The door's intake controls the burn rate. Open more for a hotter burn during heat-up. Crack it back to a smaller opening once you're holding temperature.
Step 5: stir the water with the paddle every 15 to 20 minutes. Convection circulates the water in a slow loop, but a stir mixes the warm top layer with the cooler bottom and evens out the temperature. Skipping this gives you a warm top with a cold seat. Stir it.
Step 6: keep the insulated cover on. The cover keeps heat in while the fire builds and stops cold air from pulling heat back out. Leave the cover on the whole way through heat-up. Lift it only when you check the paddle and the thermometer.
That's the routine. The fire does the work. Your job is to feed it and stir.
How long it takes to heat up
Real numbers, measured from cold start with seasoned hardwood, on a typical Perth evening.
- About 1 hour to 30°C. This is "warm enough for kids" temperature. The Australian guidance for children in hot tubs caps the water at 35°C.
- About 1.5 hours to 35°C. First-time owners with young kids should target this and stop here. Adults can soak here too if you prefer a gentler heat.
- About 2 hours to 38°C. The standard "ready to soak" point for adults.
- About 2.5 hours to 42°C. The upper end of the comfort range for most adults and the practical maximum.
Three variables move those times by ten to twenty per cent in either direction. The density of the wood (ironbark goes noticeably further than spotted gum). The starting water temperature (water that's been sitting in the tub all day in a Perth summer starts much warmer than freshly filled winter mains water). The ambient air temperature (a still 18°C summer evening loses heat much more slowly than a 5°C winter night with wind).
If you light the fire two and a half to three hours before you actually want to get in, you'll never be the parent standing in the cold with kids in dressing gowns waiting for water to warm up.
The best wood for an Aussie wood-fired hot tub
The single biggest variable in how well the tub performs is the wood. The right fuel is well-seasoned Australian hardwood. Seasoning matters more than the exact species, but a handful of Aussie hardwoods stand out for heat output and burn time.
Red Ironbark and Grey Ironbark. The hottest and densest hardwoods available in Australia. Long, even burn. The strongest single choice for sustained soak temperatures.
Jarrah. A WA native, dense, long-burning, and the natural pick for Perth and broader WA customers because of local availability. Most of our Perth customers run on jarrah and report no need to look further.
Blackbutt. A dense, hot, long-lasting burn. Widely available on the east coast.
Spotted Gum. The reliable workhorse: consistent heat output, even burn, broadly stocked across the country.
Wandoo. Another WA hardwood, exceptionally dense. Excellent fuel where it can be sourced.
The seasoning rule is firm. Wood must be split, stacked with airflow underneath and around it, and dried for six to twelve months before burning. The denser species like ironbark and red gum need closer to twelve. The pattern most Aussie owners settle into is to buy and stack in late spring or early summer so the wood has the full warm season to dry before winter use.
What not to burn:
- Softwoods like pine and fir. They burn fast, smoke heavily, and accelerate creosote build-up in the flue.
- Unseasoned or green wood. Same reasons. A green fire is a smoky fire and a smoky fire is an unhappy neighbour.
- Treated timber, painted offcuts, construction scrap. The fumes are toxic and the residues damage the stove.
How much you'll use per soak: roughly two to three armloads of well-seasoned hardwood. That covers the initial fire-up from cold and one or two top-ups to hold temperature through a full session for two or three people. The exact amount shifts with wood density, starting water temperature, and the ambient air temperature on the night.
Three mistakes first-time owners make
Three issues account for almost every first-time wood-firing problem.
1. Firing before the tub is filled. The internal heater needs water around it to dissipate the heat the fire produces. Lighting a fire with an empty or partly-filled tub will warp the heater and can damage it permanently. The order is always fill first, then fire. Never the other way around.
2. Bad timing. A wood-fired hot tub takes time to come up from cold. The tub reaches around 30°C in roughly an hour, 38°C in two hours, and 42°C in two and a half hours from a cold start. First-time owners often light the fire when they want to get in. The result is a long wait and a fire that's burnt down by the time the water is warm. Light the fire two to three hours before you actually want to soak.
3. Soaking with the cover off during heat-up. The cover holds heat in while the fire is building and stops cold ambient air from pulling heat back out of the water. Without it, the same wood load delivers a noticeably cooler soak and the heater works harder for longer to compensate. Keep the cover on through the entire heat-up phase. Only remove it when you're ready to get in.
Avoid those three and the rest of it is genuinely easy.
Safety: the non-negotiables
A wood-fired hot tub is a real product with real heat. The non-negotiables here are short and they all matter.
Water temperature. The comfort range is 37 to 40°C. Forty degrees is the practical maximum for adults. Above that, the risk of overheating, dizziness, and burns rises sharply with very little gain in enjoyment. For children, the maximum is lower, around 35°C, because their bodies regulate temperature less effectively than adults. Pregnant women should avoid hot tub use, particularly in the first trimester. Soaking after drinking alcohol is unsafe: dehydration is rapid and judgement is impaired.
Children. Children under five should not use the tub. Older children should only use it when they can stand on the bottom with their head fully above water, and never without an adult present. Drowning is the dominant risk and supervision is the single most important control. Drop the water temperature whenever kids are in.
Burn risk from the stove and chimney. The wood-fired stove, snorkel, and chimney run extremely hot during firing. Skin contact causes immediate, serious burns. Households with young children or pets should install a heat shield or a physical barrier around the stove and chimney for as long as the fire is live. Keep firewood, kindling, and any other combustibles back from the stove.
Soak duration. Cap individual soak sessions at fifteen to twenty minutes, particularly for first-time users, at the upper end of the temperature range, or after exercise. Hydrate before getting in and after getting out. Exit the tub immediately if you feel dizzy, light-headed, or nauseated.
Fire, ventilation, and structural setup. Wood-fired hot tubs are outdoor products. They must never be used indoors, in a garage, or under enclosed roofing. Keep airflow clear around the stove and chimney. Never fire the stove without water in the tub. The internal heater needs water around it to shed heat, and dry-firing will warp or destroy it. Don't leave a live fire unattended for long periods. Reduce or extinguish the fire before leaving the property. Keep a bucket of water or a hose within reach during firing. No electrical appliances belong in or near the tub.
These rules sit inside the setup guide that ships with every tub. Read them, walk through them with anyone else who'll be using the tub, and stick to them.
Water care for a wood-fired hot tub
The water sits hot for the night and cools through the week, which is different from how a stock tank pool's water lives. The care routine is simple.
Three real options:
Drain and refill. For a household that soaks once a week, the simplest answer is to drain after each session and refill before the next. The tub holds around 660 litres. A garden hose fills it in thirty minutes. The drained water goes straight onto a lawn. No chemistry, no test strips.
Hold the water with chlorine. For households that soak more often, a single Hy-Clor 600 g tablet in a closed-mode floating dispenser holds the water for the working week. The pack from Bunnings holds at least 15 tablets and costs $30.90, so the winter chlorine cost is in the order of $20 to $30. One tablet at a time, closed mode, never multiple.
Hold the water with hydrogen peroxide. The chlorine-free path. Food-grade 35% hydrogen peroxide dosed weekly, the same Gypsy Pools method used widely for stock tank pools scaled down to the tub volume. No chlorine smell, gentler on skin. Higher per-litre cost, and H₂O₂ is not currently APVMA-registered as a primary pool sanitiser in Australia, so use it knowing you're operating outside the formal regulatory framework.
For most households we install for, drain and refill is the right answer. If you start soaking three or four times a week, switch to a tablet.
Common to all three: skim debris before each soak, keep the cover on between sessions, and rinse the tub at the end of winter. For the full chlorine versus hydrogen peroxide breakdown on a larger water volume, our Stock Tank Pool Water Care guide covers both methods.
Off-grid wood-fired vs the alternatives
Quick honest comparisons.
Vs a plug-in electric spa pool. Plug-in spas cost $12,000 to $25,000 installed, plus power, plus often a sparky for the dedicated circuit. They're ready when you are. The off-grid wood-fired tub costs $2,495, plus pad, plus wood. It takes a couple of hours to get hot. The fire is part of the experience. The electricity bill is zero. If the appeal is convenience, electric wins. If the appeal is value and the ritual, wood wins.
Vs an inflatable hot tub. Inflatable tubs land between $700 and $2,000 and run on a household power point. They're a real option for an apartment balcony or a rental. Lifespan is short (most owners report two to four winters before the vinyl skin gives up). The wood-fired tub costs more upfront and lasts an order of magnitude longer.
Vs a built-in concrete or fibreglass spa. A different category. A built-in spa is a $20,000 to $50,000 commitment that becomes part of the house. The off-grid wood-fired tub is a $2,500 commitment that can move with you when you do.
Vs a dedicated cold plunge. Different use case. Our Cold Plunge Tub & Outdoor Bath is the same 1.8 m oval tub without the coil kit, priced at $1,545 for cold-only use. If you want both, the Off-Grid Wood Fired Hot Tub gives you the warm soak in winter and can be run cold in summer.
The off-grid case in one line. No 15 or 32 amp circuit, no sparky, no monthly power bill, no permit on a tub this size. The trade-off is patience: two to two and a half hours from cold to soak. For a household that likes the fire as part of the ritual, that's a feature, not a cost.
How long do they last
Honest answer: the steel tub will outlast most other things in your backyard. The wood-fired components are mechanical parts that need an eye on them.
The tub. G90-coated galvanised steel is the same coating spec used on Australian rural water tanks that hold their job for fifteen to twenty-five years. With the cover on between soaks and a drain-and-rinse every six to twelve months, the tub itself should comfortably stay in service for a decade and probably longer. Inspect the rim every few months. Touch up any superficial damage with a zinc-rich coating from any hardware shop, the same maintenance you'd do on a galvanised water tank.
The coil. Marine-grade stainless steel. Treated properly (never dry-fired, water in the tub before every fire, drained and stored dry if you're packing up for summer), it'll last many seasons. The most common cause of coil failure is dry-firing once. Don't.
The stove and chimney. Brushed clean of ash every few fires. Creosote in the flue cleared annually with a chimney brush ($30 to $50). The stove door gasket is a wear part, replace every couple of years for $20 to $40.
The cover. Insulated covers degrade in UV. A cover kept under a verandah lasts two to four years. A cover left in direct WA sun all summer lasts closer to one. Replacements are available from any pool shop.
Should you buy the bundled tub or just the coil kit
A real question that we get every week.
Buy the bundled Off-Grid Wood Fired Hot Tub ($2,495) if: this is your first wood-fired tub, you want one product that works on day one, and you don't already own a compatible tub. This is what most customers buy.
Buy the standalone Off-Grid Wood Fired Coil Kit ($950) if: you already own a Cold Plunge Tub & Outdoor Bath (the same 1.8 m oval tub) and want to convert it for winter use, or you have a compatible 1.8 m oval tub from another source.
A practical "buy both over time" path that some customers take: start with the Cold Plunge Tub & Outdoor Bath at $1,545, use it cold through summer, then add the coil kit for $950 ahead of winter. Total spend matches the bundled tub at $2,495, but the cash is split across two seasons.
What we'd suggest against: trying to fit the coil kit to a Family Plunge (2,650 litres) or an Urban Plunge (1,476 litres). The Family Plunge holds too much water for the coil to heat in a reasonable time, the maths just doesn't work. The Urban Plunge is workable but takes roughly four to five times the heat-up time of the proper hot tub. If your goal is wood-fired soaks specifically, the right product is the Off-Grid Wood Fired Hot Tub. For the full stock tank pool case (with notes on heating options for the larger pools), see our Australian Stock Tank Pool Guide.
Alt: Terra Tanks 1.8m oval outdoor tub styled for a warm soak
Common questions
Do I need council approval? Generally no. The rules that trigger a building permit and a pool barrier are based on water depth. The 0.61 m depth sits inside the spa/hot tub exemption in most states (see the WA Swimming pool and spa safety barrier requirements). Always confirm with your council. Our permit guide for WA covers it in detail.
Can I run it through the heat of summer? Yes. Skip the wood firing and use the tub cold as a plunge. Most owners fire through autumn, winter and spring and run cold in the height of summer.
How long does the heat hold without re-firing? With the insulated cover on and the fire damped down, the tub holds usable warmth for several hours after the fire dies. One fire is enough for a Saturday-night soak. For a weekend of sessions, a small Sunday-morning top-up fire brings it back up.
Can two adults and two kids fit? Two adults are the design capacity. A second adult plus two small kids is workable for a short session. Four adults is too many.
Does the cover go on during firing? Yes, through the entire heat-up phase. Take it off when you get in.
Can I use a wood-fired tub at a rental property? Yes, with the landlord's permission. The tub isn't plumbed and isn't wired, so there's no permanent change to the property. Check bushfire restrictions and any council rules about open flames first.
What if I don't like it? You have 30 days from delivery to return the tub, even if you've used it. Return shipping to our nearest metro warehouse is on you. Refund of the purchase price minus any committed third-party costs.
What to do next
Three options, no pressure.
If you're still researching, read our Australian Stock Tank Pool Guide for the broader category context and our stock tank pool water care guide for the chemistry side. State-specific guides for Perth, Sydney, Melbourne, Brisbane and Adelaide are publishing on a weekly cadence.
If you want a quote for your suburb including delivery, drop us a line at hello@terratanks.com.au. We'll come back with the all-in number.
If you're ready to look at the product page, the Off-Grid Wood Fired Hot Tub has full specs, photography, and our standard delivery and refund terms. If you've already got a compatible tub, the Off-Grid Wood Fired Coil Kit is available on its own.
We're a small Perth team. Eduardo answers the phone. George does the deliveries and the firing demos. If a wood-fired hot tub isn't right for your situation, we'll tell you and we'll point you to whatever is.
Welcome to the category. Light the fire.
Terra Tanks imports galvanised steel plunge pools, wood-fired hot tubs, and recovery tubs into Australia. We're based at 17 Treeby St, Coolbellup, WA. Get in touch at hello@terratanks.com.au or 0421 824 725.