Steam & Oak Ruutu 300 Thermowood Cube Sauna with Glass Front (Electric or Wood-Fired) - + Harvia Club 13.5kW, three phase

Steam & Oak Ruutu 300 Thermowood Cube Sauna The Ruutu 300 is the largest cabin in the Ruutu range: 3.07 metres wide and 2.32 metres deep, one open hot room with the heater at the back and the benches either side of it, and a front that is almost all glass. Four tall panes of tempered, tinted 8mm glass, one of them the door, run across the front, so everyone on the benches looks out at the garden. It seats two to six, in 46mm thermowood with softly rounded corners and stainless steel bands. Why the corners are rounded On a conventional cube the roof and the walls meet at hard edges, and every edge is a joint where rain can sit and work its way in. On the Ruutu the roof curves down into the sides, so the shingles run over a rounded edge rather than a seam, and there is nothing flat for water to pond on. Inside, the same curve leaves fewer tight corners where air stalls. Why the bands are stainless The Ruutu is built like a barrel: solid staves held in compression by steel bands, rather than thin cladding over a frame. Timber shrinks each time the sauna is heated and swells again through a wet winter, so the bands work constantly. Ordinary steel bands eventually rust and stain the timber. Stainless steel does not. 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 and resists rot without chemical treatment, in a structure that depends on staying tight. Choose your heater at checkout Shell only. The complete sauna, you source your own heater. Harvia Club 13.5kW. A large floor standing heater built for bigger rooms and heavy use. It runs on a three phase supply only. Harvia Club 13.5kW WiFi. The same heater with app control, supplied with the Harvia door sensor required for remote starting. Three phase only. Harvia Pro 20 wood fired. A 24.1kW log burning stove, rated by Harvia for rooms of 10 to 30m³, with a large firebox and a big load of stones. No electrical supply needed. Supplied with a stainless steel chimney. Sizing the heater. Harvia size heaters on the room volume, then add 50% for solid timber walls and about 1.2m³ for every square metre of glass. We estimate the hot room at about 11.5m³ from the plan, and with around 3.1m² of glass across the front it behaves more like 21m³. That is too much for a 9kW or 10.8kW heater or for gas, so the factory fits the 13.5kW Harvia Club or the Pro 20 wood stove, and those are the heaters we offer. The Club is working near the top of its range in a room like this, so for heavy winter use, or if you are single phase, choose the Pro 20. We would rather sell you the right heater than the cheapest one. Tell us where the sauna is going and how you plan to use it, and we will confirm the choice with you before you order. Before you order: your electricity supply The electric heaters are not plug in appliances. The Harvia Club heaters need a three phase supply, which most UK homes do not have, so check before you choose one. If you are single phase, the wood fired Pro 20 is the way to heat a room this size. Budget for a qualified electrician and a Part P sign off. The wood fired options need no electrical supply for the heater. 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: 46mm thermowood staves Bands: Stainless steel tension bands Front: Tempered, tinted 8mm glass: two full height panes of 65 x 177cm, one of them the entrance door, and two narrow panes of 22.5 x 180cm Benches: Straight or L shaped benches in black alder or aspen Floor: 18mm pine floor boards Roof: Bitumen shingles, or without Trim: Decorative boards front and back What's included Cabin in 46mm thermowood Stainless steel tension bands Glass front with glass entrance door Sauna benches in black alder or aspen Timber floor Bitumen shingle roof, unless you choose without Decorative boards front and back Heat resistant heater protection plates Your chosen heater, on all variants except shell only, with the chimney on the wood fired options Harvia door sensor, on the WiFi versions Options available Benches: straight benches, or L shaped benches wrapping round two walls Roof: bitumen shingles in black, grey, red or green, or no shingles Lighting: LED strips under the benches and behind the back rests, and a sauna lamp with cover Comfort: head rests and back rests Safety: a timber heater safety fence Finish: factory painting in a choice of colours Accessories: bucket and ladle, thermometer and hygrometer, sauna hourglass Ask us for a configured quote. Specifications External size: 307cm wide x 232cm deep x 226cm high Inside depth: about 200cm Hot room: about 298cm wide, around 11.5m³ (our estimate from the

Product information updated: 29 Oct 2026