Steam & Oak Vanne 3m Thermowood Barrel Sauna (Electric or WiFi Heater)

Steam & Oak Vanne 3m Thermowood Barrel Sauna

A 3 metre thermowood barrel at 235cm diameter, which makes it one of the widest barrel saunas sold in the UK. Wider means you sit further from the heater and further from the person opposite, so a full session stays comfortable rather than cramped. The walls are 44mm thermally modified timber, thicker than the 38mm most imported barrels are built from.

What thermowood actually does

Thermowood is timber that has been heat treated at around 200°C rather than chemically preserved. The process breaks down the sugars and resins that fungus feeds on and permanently reduces how much moisture the wood can reabsorb. The practical result outdoors is timber that moves less through wet British winters, resists rot without chemical treatment, and holds its shape in a structure that depends on staying perfectly round.

It costs more. Across four UK retailers who sell the same barrel in both woods, the thermowood version runs 22% to 24% dearer than spruce. On a garden building that lives outside permanently, that is the upgrade worth paying for.

Choose your heater at checkout

• Shell only. The complete barrel, you source your own heater.
• Harvia Cilindro PC90 9kW. The classic Cilindro pillar with its tall stone column, 90kg of stones, controls built into the heater.
• Harvia Cilindro PC90XW 9kW WiFi. The same heater with MyHarvia app control, so you can start it from the house. Supplied with the Harvia door sensor, which the electrical sauna standard requires before any heater can be started remotely. Most sellers leave that part off the quote.
• Harvia Legend PO110XW 10.8kW WiFi. This is the one we recommend. App control as above, with more output. Solid timber barrel walls are not insulated panels, and Harvia size heaters very differently for the two. On a barrel this wide, we would rather you had the headroom than not, especially on an exposed site or in February. It is £500 more than the 9kW WiFi.

We would rather sell you the right heater than the cheapest one. Tell us where the barrel is going and how you plan to use it, and we will confirm the output with you before you order.

Before you order: your electricity supply

These are not plug in appliances. For the 9kW Harvia specify a 3 x 16A supply on three phase, or a single 50A supply on 10mm² cable if your property is single phase, which most UK homes are. Over a buried run to a garden building that cable size usually needs to go up again for voltage drop. Budget for a qualified electrician and a Part P sign off. The 10.8kW has its own supply requirement and we confirm that with you directly rather than printing a figure here.

Tell us your supply type and main fuse rating when you enquire and we will tell you honestly what will and will not work before you commit.

Build and finish

• Walls: 44mm thermowood
• Benches: Linden
• Floor: Terrace boards
• Roof: Two layer bitumen shingles
• Lighting: One internal and two external Harvia light fittings as standard
• Bands: Tension bands

What's included

• Barrel shell in 44mm thermowood
• Pre-cut wall staves and tension bands
• Linden benches
• Terrace board floor
• Two layer bitumen shingle roof
• Tempered glass door
• One Harvia light fitting inside, two Harvia lights outside
• Your chosen Harvia heater, on all variants except shell only
• Harvia door sensor, on the two WiFi versions

Options

Available to order on this barrel: L shaped two tier benches, a 50cm length extension, LED lighting under the benches, a Bluetooth speaker system, panoramic front or rear windows, stainless steel banding, and a choice of exterior finish and shingle colour. Ask us for a configured quote.

Specifications

• Length: 300cm
• External diameter: 235cm
• Height: 240cm
• Weight: 950kg
• Seats: 4
• Wall thickness: 44mm thermowood
• Use: Outdoor only
• Heater: Harvia electric, selected at checkout, or shell only

Delivery and site preparation

• Weight: 950kg, palletised. You will need a way to move it from the kerb.
• Base: A stable, level base must be ready before delivery.
• Electrical: See the supply note above. Qualified electrician required.
• Assembly: Self assembly, typically two people over one to two days.

Not sure which configuration suits your garden? Read our complete UK Sauna Buying Guide, or message us and we will confirm the specification with you before you order. If you want the same build in black at two metres, see the Hiili 2m Black Thermowood Barrel.