{"product_id":"steam-oak-holvi-400-thermowood-barrel-sauna","title":"Steam \u0026 Oak Holvi 400 Thermowood Barrel Sauna (Gas, Electric or Wood-Fired)","description":"\u003ch2\u003eSteam \u0026amp; Oak Holvi 400 Thermowood Barrel Sauna\u003c\/h2\u003e\n\u003cp\u003eThe Holvi 400 is a 4 metre barrel laid out in three spaces: a 60cm covered terrace at the door, a 1 metre changing room with its own benches, and a hot room about 2.4 metres long behind a tempered, tinted glass door. The changing room is what makes a barrel this size work through a British winter. You undress and cool down in a dry, sheltered room, the hot room stays hot because its door opens into the changing room rather than outdoors, and wet towels stay out of the heat. It comes in two widths, Ø1.97m or the taller Ø2.27m, both in 46mm thermowood staves with stainless steel bands.\u003c\/p\u003e\n\u003cp\u003eEvery part of the layout can be changed. The barrel can be built without the changing room for a longer hot room, or without the terrace, and we will confirm the hot room size for any layout before you order.\u003c\/p\u003e\n\u003ch3\u003eWhich width?\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eØ1.97m.\u003c\/strong\u003e 2.08 metres high, a 6m³ hot room. Quicker to heat and a smaller heater does the job. Door 70 x 160cm.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eØ2.27m.\u003c\/strong\u003e 2.38 metres high, a 8.06m³ hot room. More headroom on the upper bench, which is where the heat is, and a little more room to lie down. Door 70 x 180cm.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003eWhy the bands are stainless\u003c\/h3\u003e\n\u003cp\u003eA barrel only stays round and tight because the bands keep the staves pressed together. Timber shrinks each time the sauna is heated and dries out, then swells again through a wet British winter, so the bands work constantly and need checking and re-tightening over the life of the sauna. Ordinary steel bands eventually rust, and rust runs down the timber and stains it. Stainless steel does not, and on the Holvi it is standard.\u003c\/p\u003e\n\u003ch3\u003eWhat thermowood actually does\u003c\/h3\u003e\n\u003cp\u003eThermowood 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.\u003c\/p\u003e\n\u003ch3\u003eChoose your heater at checkout\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eShell only.\u003c\/strong\u003e The complete sauna, you source your own heater.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eHarvia Cilindro PC90 9kW.\u003c\/strong\u003e The classic Cilindro pillar with its tall stone column, 90kg of stones, controls built into the heater. Harvia rate it for rooms of 8 to 14m³.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eHarvia Cilindro PC90XW 9kW WiFi.\u003c\/strong\u003e 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.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eHarvia Legend PO110XW 10.8kW WiFi.\u003c\/strong\u003e More output than the 9kW, with MyHarvia app control and the Harvia door sensor supplied.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eHarvia M3 wood fired.\u003c\/strong\u003e The classic Finnish log burning stove, rated by Harvia for rooms of 6 to 13m³. No electrics at all, no standing charge, and the ritual of building the fire. Supplied with a stainless steel chimney, and we confirm the chimney route with you before you order.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eHarvia M3 SL wood fired, through wall feed.\u003c\/strong\u003e The same stove, loaded through the wall from outside the hot room, so you feed the fire without letting the heat out or carrying logs past bathers.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003e\u003cstrong\u003eSizing the heater.\u003c\/strong\u003e Harvia size heaters on the room volume, then add 50% for solid log walls and about 1.2m³ for every square metre of glass, because both soak up heat that an insulated panel would not. On the Ø1.97m Holvi 400 the hot room behaves like about 10m³, and on the Ø2.27m like about 13m³. The 9kW Cilindro suits the narrower barrel, and on the wider one we also offer the 10.8kW Legend for headroom. The heater list at checkout only shows the heaters that suit the width you pick. \u003c\/p\u003e\n\u003cp\u003eWe 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 choice with you before you order.\u003c\/p\u003e\n\u003ch3\u003eAlso available with gas\u003c\/h3\u003e\n\u003cp\u003ePick a gas option at checkout and the sauna ships gas ready: ventilation built for gas, plus a FinSteam gas heater package that runs on a standard UK propane bottle. No electrician, no chimney and no fire to tend. It heats in around 15 minutes from a dial.\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eBotnia 81.\u003c\/strong\u003e Our standard 8.1kW gas heater. Everything you need to run the sauna.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eAurora 81.\u003c\/strong\u003e The premium version of the same 8.1kW heater, with a better finish and detailing, oxygen depletion auto shut off and flame monitoring.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eWith the safety pack.\u003c\/strong\u003e Adds the Njord heat shield and the Halo guard rail. The heat shield lets the heater sit closer to the timber wall, and the rail stops anyone brushing the hot stones. If you have children, guests, or you rent the sauna out, choose this one.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eWithout the safety pack.\u003c\/strong\u003e Heater and stone cage only. Talk to us first, because in a curved barrel the wall leans in above the heater and we will usually recommend the heat shield.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003eFinSteam rate the 8.1kW heaters for barrels and other uninsulated rooms of up to about 8m³ of air, which is why gas is offered only where the hot room fits that range.\u003c\/p\u003e\n\u003cp\u003eEvery gas option includes the heater, the Orbis stone cage, 40kg of pre washed sauna stones, a UK propane regulator and CE marked gas hose, and our fitting and commissioning. The gas variants are built with wooden louvre vents at the sizes FinSteam specify: a low intake beside the heater drawing air from outside, and a high exhaust in the opposite corner. You source a standard 13kg propane bottle locally, and a fixed gas connection needs a Gas Safe registered engineer. \u003ca href=\"\/collections\/gas-sauna-heaters\"\u003eSee the full gas heater range\u003c\/a\u003e.\u003c\/p\u003e\n\u003ch3\u003eBefore you order: your electricity supply\u003c\/h3\u003e\n\u003cp\u003eThe electric heaters 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. The 10.8kW heater has its own supply requirement and we confirm that with you directly rather than printing a figure here. Budget for a qualified electrician and a Part P sign off. The wood fired options and the FinSteam gas variants need no electrical supply for the heater.\u003c\/p\u003e\n\u003cp\u003eTell 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.\u003c\/p\u003e\n\u003ch3\u003eBuild and finish\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eWalls:\u003c\/strong\u003e 46mm thermowood staves\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eBands:\u003c\/strong\u003e Stainless steel tension bands\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eBenches:\u003c\/strong\u003e Two full length side benches in aspen or black alder\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eTerrace:\u003c\/strong\u003e 60cm covered terrace at the door end\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eChanging room:\u003c\/strong\u003e 100cm, with two pine side benches and a tempered tinted glass door into the hot room\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eDoor:\u003c\/strong\u003e Multi layer glued timber door with a tempered double glazed window, wooden handle and lock\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eWindows:\u003c\/strong\u003e Two tempered, double glazed windows, at the front or the back of the barrel\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eFloor:\u003c\/strong\u003e 18mm timber floor boards\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eRoof:\u003c\/strong\u003e Finnish bitumen shingles\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003eWhat's included\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003eBarrel in 46mm thermowood\u003c\/li\u003e\n\u003cli\u003eStainless steel tension bands\u003c\/li\u003e\n\u003cli\u003eTwo benches in the hot room\u003c\/li\u003e\n\u003cli\u003eCovered 60cm terrace\u003c\/li\u003e\n\u003cli\u003eChanging room with two pine benches and a tinted glass door to the hot room\u003c\/li\u003e\n\u003cli\u003eGlazed timber front door with handle and lock\u003c\/li\u003e\n\u003cli\u003eTwo double glazed windows\u003c\/li\u003e\n\u003cli\u003eTimber floor\u003c\/li\u003e\n\u003cli\u003eBitumen shingle roof\u003c\/li\u003e\n\u003cli\u003eHeat resistant heater protection plates\u003c\/li\u003e\n\u003cli\u003eYour chosen heater, on all variants except shell only, with the chimney on the wood fired options\u003c\/li\u003e\n\u003cli\u003eHarvia door sensor, on the WiFi versions\u003c\/li\u003e\n\u003cli\u003eGas ventilation set, Orbis stone cage, 40kg stones, propane regulator and gas hose, on the gas variants\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003eOptions available\u003c\/h3\u003e\n\u003cp\u003eThe Holvi 400 can be configured to suit your garden:\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eWidth:\u003c\/strong\u003e Ø1.97m or Ø2.27m, selected at checkout\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eLayout:\u003c\/strong\u003e without the changing room, or without the terrace\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eWindows:\u003c\/strong\u003e at the front, at the back, or both\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003ePanoramic glass:\u003c\/strong\u003e tinted, toughened glass across half of the back wall, or the entire back wall with a heater safety fence\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eGlass front:\u003c\/strong\u003e a full tinted glass facade with a glass entrance door\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eDoor:\u003c\/strong\u003e a tinted glass door, or a wood framed glass door with lock, in place of the timber door\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eBenches:\u003c\/strong\u003e premium benches with back rests, in the hot room and the changing room\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eRoof:\u003c\/strong\u003e bitumen shingles in black, grey, red or green, or natural wooden shingles\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eLighting:\u003c\/strong\u003e LED strips under the benches and behind the back rests, in white or colour, and a sauna lamp with cover\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eComfort:\u003c\/strong\u003e head rests and back rests\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eSafety:\u003c\/strong\u003e a timber heater safety fence\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eFinish:\u003c\/strong\u003e factory painting in a choice of colours\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eAccessories:\u003c\/strong\u003e bucket and ladle, thermometer and hygrometer, sauna hourglass, water tank for the wood stove\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003eAsk us for a configured quote.\u003c\/p\u003e\n\u003ch3\u003eSpecifications\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eLength:\u003c\/strong\u003e 400cm\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eWidth and height:\u003c\/strong\u003e Ø197cm and 208cm high, or Ø227cm and 238cm high\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eHot room:\u003c\/strong\u003e 6m³ (Ø1.97m) or 8.06m³ (Ø2.27m)\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eChanging room:\u003c\/strong\u003e 100cm\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eTerrace:\u003c\/strong\u003e 60cm\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eSeats:\u003c\/strong\u003e 6 to 8\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eWall thickness:\u003c\/strong\u003e 46mm thermowood\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eFloor:\u003c\/strong\u003e 18mm\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eDoor:\u003c\/strong\u003e 70 x 160cm (Ø1.97m) or 70 x 180cm (Ø2.27m)\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eWindows:\u003c\/strong\u003e 2, each 29.5 x 58cm\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eWeight:\u003c\/strong\u003e about 1,600kg (Ø1.97m) or 1,800kg (Ø2.27m)\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eUse:\u003c\/strong\u003e Outdoor only\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003eDelivery and site preparation\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eDelivery:\u003c\/strong\u003e Flat packed on one pallet, 410 x 120 x 120cm, around 1,600kg (Ø1.97m) or 1,800kg (Ø2.27m). You will need a way to move it from the kerb. Factory assembled delivery is also available, quoted separately, and needs a crane on the day.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eLead time:\u003c\/strong\u003e confirmed at order\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eBase:\u003c\/strong\u003e a stable, level base must be ready before delivery. Send us photos of your site and we will tell you what it needs.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eElectrical:\u003c\/strong\u003e for the electric heaters, see the supply note above. Qualified electrician required.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eGas:\u003c\/strong\u003e standard UK 13kg propane bottle, sourced locally. Gas Safe registered engineer required for a fixed connection.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eChimney:\u003c\/strong\u003e the wood fired options need a flue, with clearance from buildings and overhanging trees.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eAssembly:\u003c\/strong\u003e self assembly from the kit, typically two people over one to two days\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003eWant a bigger changing room? The \u003ca href=\"\/products\/steam-oak-holvi-450-thermowood-barrel-sauna\"\u003eHolvi 450\u003c\/a\u003e has 1.5 metres. Not sure which configuration suits your garden? Read our \u003ca href=\"\/pages\/sauna-buying-guide-uk\"\u003ecomplete UK Sauna Buying Guide\u003c\/a\u003e, or message us and we will confirm the specification with you before you order.\u003c\/p\u003e","brand":"Steam \u0026 Oak","offers":[{"title":"Ø1.97m, 2.08m high \/ Shell only","offer_id":62949395595651,"sku":"HOL400T-197-SHELL","price":12145.0,"currency_code":"GBP","in_stock":true},{"title":"Ø1.97m, 2.08m high \/ + Harvia Cilindro PC90 9kW","offer_id":62949395628419,"sku":"HOL400T-197-PC90","price":12945.0,"currency_code":"GBP","in_stock":true},{"title":"Ø1.97m, 2.08m high \/ + Harvia Cilindro PC90XW 9kW WiFi (incl. door sensor)","offer_id":62949395661187,"sku":"HOL400T-197-PC90XW","price":13845.0,"currency_code":"GBP","in_stock":true},{"title":"Ø1.97m, 2.08m high \/ Gas: Botnia 81, no safety pack","offer_id":62949504385411,"sku":"HOL400T-197-GAS-BOT-R14","price":14240.0,"currency_code":"GBP","in_stock":true},{"title":"Ø1.97m, 2.08m high \/ Gas: Aurora 81, no safety pack","offer_id":62949504418179,"sku":"HOL400T-197-GAS-AUR-R14","price":14440.0,"currency_code":"GBP","in_stock":true},{"title":"Ø1.97m, 2.08m high \/ Gas: Botnia 81 with safety pack","offer_id":62949504450947,"sku":"HOL400T-197-GAS-BOT-R14S","price":14540.0,"currency_code":"GBP","in_stock":true},{"title":"Ø1.97m, 2.08m high \/ Gas: Aurora 81 with safety pack","offer_id":62949504483715,"sku":"HOL400T-197-GAS-AUR-R14S","price":14740.0,"currency_code":"GBP","in_stock":true},{"title":"Ø1.97m, 2.08m high \/ + Harvia M3 wood fired","offer_id":62949395825027,"sku":"HOL400T-197-M3","price":12915.0,"currency_code":"GBP","in_stock":true},{"title":"Ø1.97m, 2.08m high \/ + Harvia M3 SL wood fired, through wall feed","offer_id":62949395857795,"sku":"HOL400T-197-M3SL","price":12915.0,"currency_code":"GBP","in_stock":true},{"title":"Ø2.27m, 2.38m high \/ Shell only","offer_id":62949395890563,"sku":"HOL400T-227-SHELL","price":12245.0,"currency_code":"GBP","in_stock":true},{"title":"Ø2.27m, 2.38m high \/ + Harvia Cilindro PC90 9kW","offer_id":62949395923331,"sku":"HOL400T-227-PC90","price":13045.0,"currency_code":"GBP","in_stock":true},{"title":"Ø2.27m, 2.38m high \/ + Harvia Cilindro PC90XW 9kW WiFi (incl. door sensor)","offer_id":62949395956099,"sku":"HOL400T-227-PC90XW","price":13945.0,"currency_code":"GBP","in_stock":true},{"title":"Ø2.27m, 2.38m high \/ + Harvia Legend PO110XW 10.8kW WiFi (incl. door sensor)","offer_id":62949395988867,"sku":"HOL400T-227-PO110XW","price":14445.0,"currency_code":"GBP","in_stock":true},{"title":"Ø2.27m, 2.38m high \/ Gas: Botnia 81, no safety pack","offer_id":62949504516483,"sku":"HOL400T-227-GAS-BOT-R14","price":14340.0,"currency_code":"GBP","in_stock":true},{"title":"Ø2.27m, 2.38m high \/ Gas: Aurora 81, no safety pack","offer_id":62949504549251,"sku":"HOL400T-227-GAS-AUR-R14","price":14540.0,"currency_code":"GBP","in_stock":true},{"title":"Ø2.27m, 2.38m high \/ Gas: Botnia 81 with safety pack","offer_id":62949504582019,"sku":"HOL400T-227-GAS-BOT-R14S","price":14640.0,"currency_code":"GBP","in_stock":true},{"title":"Ø2.27m, 2.38m high \/ Gas: Aurora 81 with safety pack","offer_id":62949504614787,"sku":"HOL400T-227-GAS-AUR-R14S","price":14840.0,"currency_code":"GBP","in_stock":true},{"title":"Ø2.27m, 2.38m high \/ + Harvia M3 wood fired","offer_id":62949396152707,"sku":"HOL400T-227-M3","price":13015.0,"currency_code":"GBP","in_stock":true},{"title":"Ø2.27m, 2.38m high \/ + Harvia M3 SL wood fired, through wall feed","offer_id":62949396185475,"sku":"HOL400T-227-M3SL","price":13015.0,"currency_code":"GBP","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0988\/1187\/1619\/files\/01-holvi-400-door-open.jpg?v=1793017652","url":"https:\/\/www.steamandoak.co.uk\/products\/steam-oak-holvi-400-thermowood-barrel-sauna","provider":"Steam\u0026Oak","version":"1.0","type":"link"}