How do you build a steam room at home?

To build a home steam room, frame a small, enclosed room, line it with cement board and a steam-rated waterproof membrane, tile it with a sloped ceiling, add a floor drain and a vapor-tight glass door, then install a steam generator outside the room with a steam head inside. Plumbing and electrical work should be done by licensed trades.

Is a steam room or sauna better for a home?

A sauna is usually easier for a home because it needs no waterproofing, plumbing or drain, and can be a prefab cabin. A steam room fits naturally into a bathroom remodel where tile, drain and water are already present. Choose steam if you prefer humid heat around 40-50 °C; choose a sauna for drier heat of 70-90 °C.

What size steam generator do I need?

Size the steam generator from the room's volume, then adjust for wall material, ceiling height and any exterior walls, using the manufacturer's sizing chart. Stone, solid tile on masonry and large glass areas absorb heat and need a larger unit than acrylic or insulated walls. Many residential rooms use generators in the 4-12 kW range.

How hot is a steam room?

A steam room usually runs at about 40-50 °C (104-122 °F) with humidity near 100%. It feels hotter than its temperature because sweat cannot evaporate in saturated air. A 2026 University of Jyväskylä study of 50 adults found that higher humidity raised both heart rate and core temperature during heat sessions.

Can you use drywall in a steam room?

No. The Tile Council of North America notes that no TCNA steam room details use gypsum wallboard, and the industry generally advises against it. Use cement board or foam backer board, a waterproof membrane meeting ANSI A118.10 that is rated for steam rooms, and ceramic or porcelain tile suitable for continuous moisture.

Home Steam Room: Costs, Construction and Steam vs Sauna

Q: How much does a steam room cost?

Steam room cost depends mainly on size, finishes and whether you convert an existing shower or build a dedicated room. The biggest cost drivers are the steam generator, waterproofing and tile labor, the glass door, and new electrical and plumbing runs. Converting a well-built shower is usually far cheaper than a stand-alone steam room.

Short answer. A home steam room is a sealed, fully waterproofed room, usually tiled, where a steam generator fills the air with vapor at about 40-50 °C (104-122 °F) and close to 100% humidity. Building one means a vapor-proof shell, a sloped ceiling, a floor drain, a tight glass door and a correctly sized generator, so it fits most naturally into a bathroom or shower remodel. If you want heat without plumbing and waterproofing, a home sauna is simpler.

This guide covers how a steam room works, what equipment you need, construction step by step, the main cost drivers, and how a steam room compares with a sauna.

What is a home steam room?

A steam room, also called a steam sauna room or wet sauna, heats the air with water vapor rather than hot, dry air. A steam generator, a small boiler usually installed in a closet, vanity or basement up to the distance its manufacturer allows, heats water and sends steam through a pipe to a steam head inside the room.

Because the air is saturated, sweat cannot evaporate to cool you, which is why 45 °C of steam feels as intense as a much hotter sauna. A 2026 University of Jyväskylä study of 50 healthy adults found heart rate rose from an average of 79 to 121 beats per minute over 10 minutes of heat exposure, and that higher humidity added to both heart rate and core temperature increases.

There are three main ways to get steam at home:

Steam shower conversion: add a generator, sealed ceiling and full-height door to an existing or new shower.
Built in steam room: a dedicated tiled room with benches, often in a primary bath or home spa.
Prefab steam cabin: a stand alone steam room or shower enclosure, typically acrylic and glass, with an integrated generator.

Steam room vs sauna at home

Factor	Home steam room	Home sauna (traditional)	Home sauna (infrared)
Air temperature	40-50 °C (104-122 °F)	70-90 °C (158-194 °F)	45-60 °C (113-140 °F)
Humidity	Near 100%	10-20%, higher with löyly	Low
Interior	Tile, stone, acrylic, glass	Softwood (cedar, hemlock)	Softwood
Plumbing and drain	Required	Not required	Not required
Waterproofing	Full vapor-proof assembly	Vapor barrier behind wood	Usually none (prefab cabin)
Electrical	Generator circuit, often 240V	Heater circuit, often 240V	Often 120V for small cabins
Prefab option	Steam cabins	Indoor cabins and kits	Most models prefab
Maintenance	Descaling, drying, grout care	Wiping benches, airing	Minimal

The health research base is also different. Most long-term studies, summarized in a 2018 systematic review by Hussain and Cohen, concern dry sauna bathing, and the findings should not be assumed to transfer to steam rooms. For a full side-by-side, see sauna vs steam room.

Steam room equipment checklist

A residential steam room needs:

Steam generator sized to the room, with a separate dedicated electrical circuit.
Steam head mounted low on the wall, 6-12 in (15-30 cm) above the floor and away from the bench, so nobody's feet or legs are in the jet.
Control panel inside the room, with timer and temperature setting.
Water supply line to the generator and, on most units, a drain or safety valve outlet.
Vapor-tight door, usually tempered glass, full height or with a transom that can be closed.
Floor drain and a sloped floor.
Wet-rated lighting, and optional aromatherapy or automatic flush and drain on the generator.

Note that steam generators are a different product category from dry sauna heaters: the US safety standard for sauna heaters, UL 875, explicitly excludes steam-bath heaters. Buy a generator listed for steam bath use in your market.

Sizing the steam generator

Generator size depends on room volume and on what the walls are made of. Heavy materials such as natural stone, tile over masonry and large glass panels soak up heat, so manufacturers' charts multiply the effective volume for them. Exterior walls, high ceilings and cold climates push the size up further. Many residential rooms land in the 4-12 kW range; use the specific generator's sizing chart rather than a general rule.

How to build a steam room: step by step

Pick the location. Bathrooms are ideal because water, drain and ventilation already exist. Keep the room small; 4 x 4 ft to 6 x 8 ft (1.2 x 1.2 m to 1.8 x 2.4 m) covers most homes.
Limit the ceiling height. Most designers keep steam room ceilings at 8 ft (244 cm) or below, and many go lower, because every cubic foot needs more steam.
Slope the ceiling. A sloped ceiling, commonly about 1-2 in per foot (8-17%), lets condensation run down the walls instead of dripping on bathers.
Frame and insulate. Insulate the walls and ceiling, especially exterior walls; the Tile Council of North America notes that temperature differences across the wall can cause condensation in the cavity.
Install the backer board. Use cement board or foam backer board. TCNA states that none of its steam room details use gypsum wallboard.
Waterproof and vapor-proof. Apply a bonded waterproof membrane meeting ANSI A118.10 and rated by its manufacturer for steam rooms. Grout is not vapor-impermeable, so the membrane, not the tile, does the work.
Rough in plumbing and electrical. Steam line, generator water supply, drain, and a dedicated circuit for the generator, sized per its manual. See sauna electrical requirements for how circuit sizing works.
Tile. Use ceramic or porcelain tile meeting ANSI A137.1 and recommended for steam use, set with steam-rated thin-set and grout, following TCNA installation methods such as SR613 or SR614.
Build the bench. Tile over a sloped, waterproofed bench so water runs off. In commercial rooms, the ADA guide to saunas and steam rooms requires a bench seat that is slip resistant and does not collect water.
Fit the door and controls. Install the vapor-tight glass door, steam head, control and wet-rated light, then commission the generator per its manual.

Can you DIY a steam room?

A do it yourself steam room is possible for experienced remodelers, but waterproofing failures are expensive and often hidden until mold or rot appears behind the tile. Many homeowners hire a tile contractor familiar with steam assemblies and licensed plumbers and electricians for the generator. Homemade steam rooms built with ordinary shower details tend to fail at the ceiling and door.

How much does a steam room cost?

Steam room price varies widely, so it is more useful to understand what drives it:

Cost driver	Why it matters
Conversion vs new room	Converting a sound shower avoids new framing, drain and much of the tile work
Room size and ceiling height	Larger volume needs more tile, membrane and a bigger generator
Wall and ceiling materials	Natural stone and large-format tile raise material and labor costs
Steam generator	Size, controls, auto-flush and aromatherapy features
Glass door and transom	Custom frameless glass is a major line item
Electrical and plumbing runs	Distance from panel and water supply; panel upgrades if needed
Prefab vs custom built	Prefab steam cabins avoid most site construction
Labor market	Tile and trade rates vary by region

If you are comparing a steam room with a sauna, our guide to how much a sauna costs covers buying, building and running costs for cabins and custom builds.

Steam room safety and use

Limit sessions to about 10-15 minutes, especially at first, and leave if you feel dizzy or unwell.
Drink water before and after; Harvard Health recommends two to four glasses after a heat session.
Avoid alcohol and medications that impair sweating.
Use the timer and keep the control reachable from inside.
Do not use it when ill, and talk to a doctor first if you have heart disease or blood pressure problems.

This article is general information, not medical advice. People who are pregnant, have heart disease, low or high blood pressure or other conditions should talk to a doctor before using a steam room or sauna.

Maintenance and steam room accessories

Run the generator's flush or descaling routine as the manufacturer directs, especially with hard water. Leave the door ajar after use so the room dries, squeegee glass and walls, and clean grout regularly. Useful steam room accessories include a teak or plastic stool, a ceiling-mounted rain head for cooling off, wet-rated lighting and essential oil reservoirs designed for the steam head. For cleaning routines that also apply to saunas, see how to clean a sauna.

Would a sauna suit your home better?

If you do not have a bathroom remodel planned, a sauna often makes more sense: it needs no drain or waterproof shell, and an indoor cabin can be assembled in a day. Many people pair the two, or add a sauna next to the bath; see bathroom sauna ideas for layouts. Mars Sauna does not make steam rooms, but it builds traditional stove saunas where pouring water on the stones gives bursts of steam. For hotel, gym or spa projects that combine wet and dry areas, contact us about sauna cabins sized to your space.

Key takeaways

A home steam room runs at about 40-50 °C (104-122 °F) and near 100% humidity, supplied by a steam generator outside the room.
It needs a fully vapor-proof assembly: cement or foam backer board, an ANSI A118.10 steam-rated membrane, tile, a sloped ceiling, a floor drain and a tight glass door.
Size the steam generator from the manufacturer's chart, adjusting for stone, glass, exterior walls and ceiling height.
Converting a sound shower is the most economical route; dedicated built-in rooms and custom glass raise steam room cost.
A sauna is usually simpler for homes without a remodel planned, since it needs no plumbing or waterproofing.