Frequently Asked Questions

Every sauna is custom-built — we have no fixed, off-the-shelf models. You design yours in our 3D builder, choosing the size, wood, heater, glass and layout and watching it come together in real time. The sizes in our catalogue are just popular starting points you can change completely, and we are always happy to help with the design.

We build in three woods: Thai domestic teak, Canadian red cedar, and Russian pine. Teak is dense and naturally weather-resistant, red cedar is light, aromatic and dimensionally stable, and pine is our most affordable option. For the cabin saunas (Fah and Narak) you choose the wood in the 3D builder and the price updates as you switch; barrel and cube saunas are built exclusively in teak.

Yes. We build oval ice baths with teak cladding, sized from single-person plunge up to multi-person configurations. Often paired with our saunas for a full hot-cold wellness setup.

Custom saunas: 28-35 days from confirmed order and deposit received. Imported items and catalogue stock: 6–10 weeks. Lead time starts once the order is confirmed and payment received.

Yes. We ship globally via sea freight, palletised or in containers depending on size. We quote FOB or CIF and the buyer handles import duties.

Within Thailand we offer full installation. We will need access to the site for 1–3 days, depending on the size of your sauna and the location. Want to see your sauna before we set off to assemble it? Let us know and we’ll arrange a visit to our factory. For everywhere else we deliver as a kit with an interactive installation manual generated for your exact sauna — not a generic guide — so it matches your specific room and layout. We are available for remote support throughout the build.

Use the voltage and phase arrangement approved for your exact heater and controller. kW alone does not decide the supply phases. Both the 3D builder and electrical manual use 220 V single-phase or 380 V balanced three-phase planning references. The Builder uses the VCT-G wall-conduit method; the manual also gives THW and buried NYY columns. Your qualified electrician must approve the actual cable, protection, earthing, capacity and voltage under load.

Prepare the agreed supply position within 3 metres before delivery, keep unfinished conductors isolated, and arrange your electrician to connect the incoming cable into Sisu’s box. The incoming supply and heater outputs are separate: Sisu’s three-group heater uses three group feeds, N and PE from the control box, regardless of the approved incoming phase arrangement. With on-site assembly, Sisu checks the incoming supply and tests the sauna. For a self-install kit, arrange qualified installation and commissioning before use.

For custom saunas with on-site assembly: 50% to confirm your order, 40% when our team arrives on site, and the final 10% within 7 days of completion. Any different payment schedule expressly agreed in the quotation takes priority.

Please be there at handover, or send someone authorised to inspect the work and sign for you. The payment schedule in your agreed quote applies.

Yes — our outdoor saunas are built to last outdoors, with proper insulation and weatherproof exterior cladding. We normally fit BlueScope galvanized steel roofing, and on some models you can choose asphalt shingles instead.

If the sauna is built into an existing room, you need a minimum of 25 mm clearance around it for ventilation. We provide an exact site plan with every order so the footprint and clearances are clear before you build.

From the inside out, our standard insulated wall has 12 mm timber cladding, 13 mm plywood, a 50 mm rockwool insulation core wrapped in foil on all sides, 13 mm plywood and 12 mm exterior timber cladding. The foil helps protect the insulation from moisture.

No — never. Indoor saunas don't have the weatherproof exterior cladding, deeper insulation, or proper roof needed for rain, sun and humidity. Putting one outside, even under a covered area, will let moisture into the wall stack within months and the wood and electrical components will start to fail. If your sauna will live outside, it has to be built as an outdoor sauna from the start.

Very. Even a properly-built outdoor sauna lasts far longer when partially sheltered — under an eave, pergola, or covered terrace. Driving rain, full sun and standing water around the base age exterior wood fastest. A small overhang above the door and a foundation that drains away from the structure add years to the cladding before any major refurbishment.

Teak, by a wide margin. Thai teak has the natural oils and density to handle our climate with the least maintenance — typically just teak oil once or twice a year. Red cedar, despite its reputation, is not what we recommend for outdoor exterior here: it weathers grey quickly and needs oiling 3–6 times a year to stay looking its best. Pine should never be installed as raw exterior cladding outdoors — the surface must first be burned (shou sugi ban).

Untreated pine swells, splits and rots quickly in our climate. Burning the surface (shou sugi ban) seals the outer layer of timber against water, insects and UV. We offer it in three depths — light, medium and dark — so you can choose the look you want; none is fully charred, the surface is simply burned to different depths. Done properly it makes pine last for years longer and gives a distinctive textured finish. For outdoor pine saunas we flame-finish the exterior face by default, and recommend doing the interior face as well so moisture cannot enter the timber from either side.

It depends on the wood and exposure. Teak: 1–2 times a year with teak oil. Shou sugi ban pine: 2–4 times a year. Red cedar: 3–6 times a year. A sauna fully under cover needs less; one in open sun and rain needs more. Check quarterly and oil whenever the wood looks dry, faded, or patchy.

At least once a month, and after every heavy storm. Look for: dark damp patches on the cladding, lifting or warping boards, gaps in silicone joints or around the door, signs of insects at the base, water pooling near the foundations, and any change to the roof. The point is to catch small issues — a popped board, a tiny leak — before they turn into moisture damage inside the wall stack, which is much harder and more expensive to fix.

More than for an indoor one — an outdoor sauna is exposed to weather every day, and staying like new for many years means treating maintenance as routine, not reactive. After every use: leave the door open so the interior dries out completely. Monthly: wipe the interior with clean water (never chemicals), check the heater stones, sweep underneath. Quarterly: full walkaround of cladding, roof, door seal, foundation drainage and silicone joints. 1–6 times a year depending on wood: re-oil the exterior. Yearly: re-check all silicone, re-tighten any loose hardware, replace any cracked heater stones, touch up any spots looking duller than the rest. A neglected outdoor sauna can look tired in 1–2 years; a properly maintained one stays beautiful for decades.

Inside, only ever clean with water — never any chemicals. Outside, the cladding needs periodic oiling and a regular eye on the weather — see the Outdoor Saunas sections above for the full schedule.

A traditional Finnish sauna runs at 70–100 °C with low humidity, raised by throwing water on the stones (löyly). We also build infrared saunas, where our IR panels run at 80–90 °C.

For healthy adults, yes — daily use is common in Finland. 15–20 minute sessions, hydrate, cool down between rounds. Anyone with heart conditions, pregnancy, or specific medical concerns should check with their doctor.

Every sauna we build is covered by a tiered warranty: 1 year on electronics (heater and controls), 5 years on the wood, and 10 years on the structure. The warranty covers manufacturing defects under normal use and proper maintenance.

Tampering with any part of your sauna without our approval voids the Sisu Sauna warranty for that sauna, where permitted by law. Your statutory rights still apply.

The warranty doesn't cover damage caused by incorrect installation by the customer or a third party, misuse, accidents, or skipping the maintenance set out in your product documents — for an outdoor sauna that means the regular oiling and inspection schedule. Normal weathering of exterior wood and consumables such as heater stones are also outside the warranty.

Warranty support starts with remote diagnosis. Covered defects and Sisu installation faults are remedied under the applicable warranty and law. If inspection confirms a fault caused by the customer, both collection and return shipping, inspection and approved repairs are chargeable at reasonable rates or an estimate agreed in advance.

Examples include a drain plug left loose or incorrectly refitted by the customer, allowing air into the circulation system and causing pump errors; and sauna bench or seat-panel damage caused by jumping, impact or other misuse. Incorrect assembly or modification of plumbing connections is also excluded where it causes or contributes to the fault. This includes applying PTFE tape to fittings designed to seal with an O-ring where tape is not specified by the manufacturer. These exclusions do not apply where the fault results from Sisu Sauna's own supply, installation or workmanship. For other products, an unrelated modification does not invalidate coverage for a separate covered defect.

Yes. We stay available after delivery for spare parts, servicing advice and remote help. Within Thailand we can arrange on-site service; elsewhere we support you remotely throughout the life of the sauna.

Contact us with your requirements and we will prepare a quote. With on-site assembly: 50% to confirm your order, 40% when our team arrives on site, and the final 10% within 7 days of completion. Record the completion date, any deferred testing and outstanding work in the signed handover acknowledgement. A different payment schedule expressly agreed in the quotation takes priority. The client must have a suitable, energised power supply ready no more than 3 metres from the agreed sauna power connection point before delivery, so the sauna can be tested after assembly. A qualified electrician must prepare the supply to the specified voltage, phase and capacity. For delivery or pickup without Sisu on-site assembly, pay 50% to confirm your order and the remaining 50% before delivery or pickup. For catalogue and imported items, full payment confirms the order.

Please be there at handover, or send someone authorised to inspect the work and sign for you. The payment schedule in your agreed quote applies.

Card payments and QR code are handled securely through Stripe. We also accept bank transfer (Kasikorn Bank) and international wire transfer for overseas orders.

We can arrange a video walkthrough of a current build, share reference projects, or — for serious enquiries — a site visit in Surin. You can also visit our showroom in Bang Saen to see a sauna in person.