Leil® Celto M 3-4 Person Outdoor Sauna

Both have the same depth (1.40 m) and height (2.10 m). The Celto S is 1.63 m wide and seats two comfortably, three at a squeeze. The Celto M is 2.02 m wide and seats three comfortably, four at most, with a longer 1.86 m bench.

If it will mostly be used by two people, the S is plenty. If you sauna with family or friends, the extra 39 cm of the M is worth it.

Yes. The Celto is only supplied as a flat-pack kit, and Leil says it can be fully assembled in 4–6 hours with the manual included.

Some panels are heavy, so plan for two people. If you would rather not build it, use the Request an Installation Quote link under Add to Cart.

CLT (cross-laminated timber) is made from layers of wood glued at right angles, so the panels are stiff and stable. The Celto walls, floor and ceiling are all 60 mm CLT panels.

Because each wall is one solid panel rather than many boards, the kit goes together quickly and stays straight.

No. Leil only makes the Celto as a flat-pack kit. It arrives on one pallet of about 0.8 × 2.0 × 1.0 m, weighing around 500 kg, and we unload it for you.

Delivery to mainland England and Wales is included. It is made to order, and we will call to book a date once it is ready.

Use a solid, well-drained base that is level from side to side. Leil recommends setting the back slightly lower than the front, so rain runs off the flat roof instead of sitting on it.

Yes. The outside timber arrives untreated, so give it a good-quality, breathable exterior finish to protect it from rain, sun and temperature changes, then check it at least once a year and re-coat as needed.

Leil finishes its own Celtos in black or graphite grey exterior wood stain. Any good exterior stain sold in the UK works, such as Tikkurila Valtti Plus or Osmo UV Protection Oil (see our paint and treatment answer above). Leave the inside walls untreated; a sauna wax or bench protector can be used on the benches.

All of these are on Leil’s list for both the S and the M. The list is fixed because the sauna room is 1.9 m high, so taller heaters do not fit:

• Harvia KIP 8 kW with heater stand (controls on the heater)
• Harvia Cilindro PC90XE 9 kW, or PC90XW with WiFi, on protective bedding (Harvia requires it, and it is included)
• HUUM DROP 6 or 9 kW with heater stand, controlled by a HUUM UKU panel: UKU Glass WiFi inside the sauna, or UKU Local or UKU WiFi fitted outside somewhere sheltered from rain and snow
• HUUM FLOW Mini wood-burning stove with chimney set

The electric heaters need a qualified electrician to connect them.

You can add a dimmable LED strip under the backrest. The set includes the LED strip, cable, transformer, dimmer switch and installation box.

No. The price shown is for the sauna without a heater. Choose your heater in "Design your sauna" on this page; the price updates as you choose.

Final wiring must be completed by a qualified electrician; electrical connection is not included with sauna assembly.

No. Our installation team can assemble the sauna, but the heater and any other electrical components must still be connected by a qualified electrician.

You will need a suitable electrical supply and, at minimum, an isolator switch. Full details are provided in the Electrical Supply section on the product page.

Yes. Any qualified electrician should be able to connect the sauna, provided they follow the electrical requirements listed in the Electrical Supply section of the product page.

After you place your order, we also send further information that you can pass on to your electrician.

In some cases, we may be able to share details of electricians who have connected saunas for previous customers.

Availability will depend on your location, and you are also welcome to use your own qualified electrician.

Assembly time depends on the model, access and site conditions. Many outdoor saunas can be assembled in around one day, while larger or more complex models may take longer.

Use the Request an Installation Quote link under Add to Cart and complete the form. We will confirm the expected installation time with your quote.

Yes. Our installation team uses specialist carpenters and installers who are experienced in assembling outdoor saunas, which is one of the reasons many customers prefer professional installation.

Outdoor saunas should be installed on a solid, level, well-drained base that is suitable for the size and weight of the model you are buying.

Suitable options can include a concrete pad, paving, tiles, or structurally suitable decking, provided the surface is flat, stable, and able to support the load without movement.

We also recommend positioning the base far enough away from walls, fences, and other obstructions to allow access for future wood treatment and maintenance, and to ensure the fuse box can still be accessed when needed.

No. We do not carry out site visits.

To request an installation quote, use the Request an Installation Quote link under Add to Cart and complete the form with photos, measurements, site plans, access details and the proposed sauna location. Our installation team will use that information to assess access, base preparation and positioning, and flag any obvious issues before installation.

In outdoor saunas, it is normal for the timber structure to respond to changes in temperature, humidity, and ambient conditions over time. This can occasionally cause minor movement in the door opening, which may affect how the door closes or sits within the frame.

For this reason, sauna door hinges are designed to be adjustable. Minor door or hinge alignment adjustments over time are normal and should be carried out in line with the manual as part of routine ownership maintenance, rather than being treated as a product fault.

We do not currently have a full showroom, but many of our existing customers are happy to show their sauna to prospective buyers.

If you would like to see one in person, please contact us and we can try to arrange a viewing with a customer in or near your area.

Yes. Outdoor saunas are not maintenance-free.

As a minimum, owners should expect to inspect and re-treat exposed timber at least every 12 months, or sooner if the manufacturer manual and local conditions require it.

You should also expect to make minor door or hinge adjustments over time in line with the manual, as timber structures naturally move slightly with changes in temperature and humidity.

In coastal or sea-air environments, exposed metal parts should be checked more regularly and protected with a rust-proof treatment such as WD-40 or another suitable anti-corrosion product.

Sauna heaters also require maintenance in line with the manufacturer manual. This normally includes periodically checking, washing, and restacking the stones, and in the longer term electric heater elements may need replacing if they wear out.

We do not currently offer a formal maintenance programme.

If your sauna has exposed or untreated exterior timber, use a breathable, UV-resistant and water-resistant exterior wood treatment. We recommend Tikkurila Valtti Plus Kesto or Tikkurila Valtti Plus Color. If you prefer a clear, natural finish, Osmo UV Protection Oil is a good option.

Apply the treatment after assembly and before regular use, then inspect the timber annually and re-treat it as required for the product and your site’s exposure.

For sauna-room walls, window frames and door frames, use Tikkurila Supi Sauna Finish or Tikkurila Supi Sauna Wax. For benches and backrests, use Tikkurila Supi Laudesuoja Bench Protection. Never use ordinary exterior paint, varnish or household wood treatments inside the heated sauna room.

If your sauna has factory-finished or specialist cladding, follow the supplied manual and do not overcoat it unless the manufacturer confirms the product is suitable.

These recommendations are general guidance. Check both the sauna manufacturer’s manual and the treatment manufacturer’s instructions, and satisfy yourself that the product is suitable for the timber and any existing finish before applying it. If you are unsure about a colour, request samples from the manufacturer or retailer and test one on a spare timber offcut or a small, inconspicuous area first.

Yes. Our traditional saunas are suitable for commercial use, and we already supply many commercial customers.

Commercial use requires a regular maintenance regime, as it would with any sauna. This includes cleaning the sauna, inspecting and maintaining the heater stones, and re-treating or painting the timber when required. The frequency will depend on usage, location and the manufacturer's maintenance instructions.