Mobile Sauna for Groups — Portable Gas Sauna Tent, 10-14 Person | FinSteam Dome

Steam & Oak is the first UK retail partner for FinSteam — bringing this Finnish portable sauna system to British events, retreats, mobile sauna hire businesses and large holiday-let amenities.

The group sauna built for hire, events, retreats — 10-14 people, hot in 15

The FinSteam Dome is a different proposition from the Fritid range. Octagonal 4 × 4 metres, 20 m³ of insulated space, designed to seat 10 to 14 people comfortably. It runs on two FinSteam 8.1 kW gas heaters in tandem (Botnia 81 or Aurora 81), hot in 15-20 minutes from cold, no electricity, no chimney, no flue penetration of any building. Built for sauna hire operators, retreat venues, festivals, wedding companies, athletic clubs, and large holiday-let amenities — places where you need a real sauna on site without a power supply, a flue, or a fire watch.

Who buys the Dome (and what business they're running)

• UK mobile sauna hire operators starting or scaling — the Dome is the flagship rentable single-unit. See our mobile sauna hire guide for the commercial case + per-session economics + venue-approval framing.
• Event companies and festival operators — wellness festivals, sports days, corporate days, weddings, recovery events. The Dome arrives on a trailer and is operational the same day.
• Retreat venues and wellness centres — especially off-grid sites where electric saunas can't reach and a fixed wood-fired sauna isn't practical.
• Large holiday lets and luxury Airbnb operators — where the sauna is the wellness amenity that books out a property at the higher tier and the unit needs to scale to a houseful.
• Athletic clubs / training groups / triathlon clubs — recovery sessions for groups after races or training blocks.
• Wedding venues and pop-up wellness operators — premium guest experiences without permanent infrastructure.
• Replacing a tired commercial wood-fired sauna tent — operators upgrading from PortaSauna HEXXL or similar wood-fired group tents who want clean gas heat, no fire watch, and faster turnaround between sessions.

Why a gas group sauna (and why it beats wood-fired commercial setups)

The commercial group-sauna market is split between fixed installations (high capex, planning, plumbing, electrics) and wood-fired group tents (continuous fire-tending, chimney safety, smoke complaints from neighbouring venues, 30-45 min warm-up that eats your session windows). The FinSteam Dome is the third option:

A clever piece of engineering — the dual-heater certified safety case

The Dome is the only NOIR / FinSteam tent designed around two heaters running together. It's not "a single-heater tent you can put a second heater in" — the Dome's vent openings, internal volume, fabric construction and dimensions are all spec'd around paired heater operation under EU Regulation 2016/426. Each heater holds an EU Type-Examination Certificate, AENOR-tested under the Gas Appliance Regulation. Each has an Oxygen Depletion Sensor that shuts the gas off at approximately 18% oxygen, and flame monitoring that cuts the gas instantly if the flame is lost. Zero warranty returns on the heater across the last 12 months.

Practical commercial benefit: running two heaters gives you redundancy mid-session. If one bottle runs out or one heater shuts down for any reason, the other carries the booking to the end. For paid commercial sessions this matters — you don't refund a £25-per-head 14-person group because a single fuel source failed.

What's in the Dome — every piece explained

1. The 3-layer engineered insulated fabric (commercial-grade construction)

Same engineered Oxford construction as the Fritid range, scaled up to the Dome's much larger footprint:

• Outer layer: 100% Oxford 420D polyester with waterproof coating. Premium black. Handles weather across multiple commercial sessions — rain, snow, high humidity. 2000 mm waterproof rating.
• Middle layer: 100% polyester fibre fill, 150 g/m² — the thermal insulation that retains sauna heat across repeat hour-long bookings.
• Inner layer: 100% Oxford 210D polyester smooth heat-retaining liner — reflects heat, doesn't trap moisture.

The 3-layer construction is what makes the Dome viable for commercial use. A single-skin tent would lose heat between sessions and require the dual heaters to work continuously to recover — economically untenable. The insulated build means the Dome holds temperature between bookings, ready for the next group with a 5-10 minute top-up rather than a full reheat.

2. Octagonal 4 × 4 m footprint

The Dome is octagonal — eight-sided — for two engineered reasons. Acoustic distribution: löyly steam distributes more evenly in a multi-faceted interior than a rectangular one, important when 10-14 people are sitting around the perimeter and you want consistent heat. Structural rigidity: an octagonal pop-up frame stays taut in wind better than a rectangular shape — critical at outdoor events.

• Footprint: 4 × 4 m (octagonal — meaning the actual covered area is slightly less, but external clearance should be planned at 4 × 4 m).
• Internal volume: 20 m³.
• Capacity: 10 to 14 people seated.

3. Dual-heater configuration (the Dome's defining feature)

The Dome requires two FinSteam 8.1 kW gas heaters running in tandem:

• Two heaters' combined output: 16.2 kW — the right thermal output for 20 m³ of insulated volume to reach 70-75°C in 15-20 minutes.
• Combined gas consumption: ~1.2 kg/h (0.6 kg/h per heater at full output). A standard 13 kg UK propane bottle runs the Dome at full output for around 10 hours; throttled at temperature, much longer. Most operators stock 4 bottles and rotate, ensuring no mid-session bottle changes.
• Heater positioning: opposite corners of the Dome — the vent geometry is designed for this paired airflow, not single-heater airflow.
• Redundancy: if one heater shuts down or runs out of gas mid-session, the other carries the booking to the end. This is a deliberate commercial feature.

You can run either two Botnia 81 R14S or two Aurora 81 R14S heaters (the safety-pack configurations are recommended for commercial use). Buying both heaters separately + the Dome costs less than a single fixed commercial sauna installation.

4. Engineered ventilation openings (designed for dual-heater airflow)

FinSteam specifically engineered the Dome's vent openings to handle paired heater airflow — different from the single-heater airflow in the Fritid range. The vents are sized and positioned to keep each heater's combustion in safe operating bands while preventing cross-interference between the two heaters. You don't modify the tent or add ventilation. The certification under EU Regulation 2016/426 covers the Dome + two heaters as a single system.

5. Setup, pack-down, and operational realities

• Setup time: 10-15 minutes with two people (the Dome's larger footprint means it's not a one-person pitch like the Fritid range).
• Pack-down: roughly the same time as setup. Trailer-friendly — pack to a single large carry-bag that fits a standard van load.
• Operational team for hire / events: two operators minimum at the venue for pitch, plus one operator per active session for safety supervision and propane management.

Made in Finland. Backed by a track record.

The Dome is manufactured to FinSteam's spec. The heaters that run inside are manufactured in Finland by FinSteam Ab Oy, all components sourced from Europe. Spare parts ship direct from the FinSteam factory. As the official first UK retail partner, Steam & Oak holds UK stock, handles UK service, and gives you a real phone number when something needs attention. Zero warranty returns on the heater across the last 12 months — important for commercial operators where downtime equals lost bookings.

Portable by default. Gas Safe registered if fixed-installation use.

The Dome and both heaters are portable — pitched at each venue, packed down between gigs. Each heater runs as a portable LPG appliance with a UK propane bottle outside, regulator and CE-marked hose. Used portably, you do not need a Gas Safe registered engineer. If you choose to fix the Dome at a permanent venue with anchored gas connections, UK regulations require a Gas Safe registered engineer for the gas connections.

The full picture — what you'll need on top of the Dome

The Dome tent on its own doesn't make you a commercial sauna unit. Plan for:

• Two FinSteam gas heaters — either two Botnia 81 R14S (value commercial pairing) or two Aurora 81 R14S (premium pairing). The S configurations are recommended for commercial use — Halo safety rails standard for paying customers, Njord heat shields included as standard. Public-liability insurers expect to see these.
• Two UK propane regulator + hose kits — our UK gas kit, one per heater. For commercial / event use with larger propane bottles (POL connector, 19-47 kg cylinders), get in touch — we can spec the right commercial gas kit.
• 2× 40 kg sauna stones — one stone load per heater. Sold standalone.
• Two Poppel benches — the Poppel 1600 or 1800, two of them, for group seating.
• Propane bottles — 4 × UK 13 kg Calor (or 2 × larger POL commercial bottles) for a typical event-day. Bought / hired locally.
• Non-combustible bases for each heater (≥30 mm thick, ≥300 × 300 mm × 2) — sourced locally per the FinSteam install spec.
• Public-liability insurance + business insurance — UK specialist brokers cover the mobile sauna niche. The CE certification + ODS auto-shutoff on the FinSteam heaters is what underwriters look at first.
• Venue paperwork: EU Type-Examination Certificate + Declaration of Conformity (we supply, on request) — venues' fire-risk assessors will ask.

Delivery + documents

Free UK delivery. The Dome ships in a larger consignment than the Fritid range — allow set-up time at the receiving end. Lead time shown above the buy button.

Documents available on request: Tent specification sheet · Dual-heater ventilation specification · EU Type-Examination Certificate (AENOR, Gas Appliance Regulation 2016/426) · EU Declaration of Conformity · UK gas connection guide · Paired-heater operating notes · Commercial / hire venue-approval brief · Recommended rental servicing schedule.

FAQs — commercial-focused

Why does the Dome need two heaters specifically?
20 m³ of insulated space is too much volume for a single 8.1 kW heater to reach genuine sauna temperature in a reasonable time. FinSteam's engineering answer was a paired heater configuration with vent geometry designed for two-heater airflow. The Dome isn't a single-heater tent that "can take a second heater" — it's a tent designed around the pair from day one, certified that way under EU Regulation 2016/426. Running two heaters also gives you mid-session redundancy: if one bottle runs out or one heater shuts down, the other carries the booking to the end.

Can I run the Dome with one heater for smaller groups?
The Dome was engineered for two heaters. Running one will reach a usable temperature for smaller groups (5-8 people) over a longer warm-up, but you lose the response time and the redundancy. For groups under 8, the Fritid X or NOIR XXL Signature two-tent setup is a better-suited match — the Dome is built for the larger group bookings.

Is the Dome a viable commercial / hire business?
Yes — it's the FinSteam tent purpose-built for it. The 10-14 person capacity, the no-electricity / no-flue setup, the rapid pitch-and-pack-down, and the heater certification make it the most rentable sauna unit FinSteam make. UK rental operators typically charge £15-25 per head per 45-60 min session, putting a busy Dome at £150-£350 per session and £600-£1,500 per event day. Most operators recoup the unit within a single busy season. See our mobile sauna hire guide for the full commercial case.

Can two people set up the Dome?
Yes — that's the practical minimum. One person can pitch a Fritid; the Dome's larger panels and 4 × 4 m footprint need a pair. Setup time is 10-15 minutes with two people.

What about planning permission and commercial use?
For private use on residential land, the Dome is usually permitted development within limits (temporary structure). For commercial use (venues, retreats, hire businesses), separate rules apply — building control, fire safety on commercial premises, public-liability cover, possibly business rates. Signpost only — not legal advice. We can introduce you to UK consultants who specialise in mobile-sauna business setup.

Do I need a Gas Safe engineer?
Not for portable use — both heaters connect outside to propane bottles via UK 37 mbar regulators and CE-marked hoses. Yes if you fix or build the heaters into a permanent commercial structure, in which case UK regulations require a Gas Safe registered installer.

How long does the Dome take to heat up, and what's the running cost?
15-20 minutes from cold to sauna temperature with both heaters running. Combined gas consumption ~1.2 kg/h (0.6 kg/h per heater at full power). A standard 13 kg UK propane bottle runs the Dome at full output for ~10 hours; throttled at temperature, much longer. At current UK propane prices (~£40 per 13 kg bottle), running cost per session is materially below what operators charge per head, leaving healthy margin.

Is it safe — and what about CO inside a sauna with two heaters running?
Yes. The tent ships with ventilation engineered specifically for the dual-heater configuration — you don't modify it. Each heater has an ODS auto-shutoff (~18% oxygen) and flame monitoring. Standard residential CO alarms aren't designed for sauna conditions (high temperature + humidity) and won't operate reliably inside; the ODS is the engineered safety case. For commercial venue approvals, we supply EU Type-Examination Certificate + Declaration of Conformity on request — venues' fire-risk assessors ask for both.

Will festivals and venues actually approve a gas sauna on site?
Generally yes — and faster than they'd approve a wood-fired one. The certified ODS auto-shutoff, no open flame, no chimney, and the freestanding portable status all simplify the venue's fire-risk assessment. We can supply venues with the EU Type-Examination Certificate, Declaration of Conformity, and a one-page operations brief for their RA file.

How does the Dome compare to the NOIR XXL Signature two-tent setup?
Different products for different use-cases. The Dome is a 4 × 4 m single octagonal group sauna built for 10-14 people in one space — requires two heaters, designed for events / rentals / commercial groups. The NOIR XXL is two smaller Fritid X tents (each 2-4 people) joined at the entrances — sauna in one tent, second function (changing room / cold plunge / sleep) in the other. Pick the Dome for group sauna at scale. Pick the XXL for sauna-suite use (couples / families / boutique pop-ups).