Short definition
A steam shower is a sealed shower stall integrated with an electric steam generator that produces low-pressure steam at about 100°C. A wall-mounted control panel selects steam mode; a steam outlet near the floor delivers the vapor; a sloped ceiling sheds condensation away from the user. Premium remodel feature.
What it is
Three components:
- Steam generator. Installed in a nearby closet, attic, or basement; piped to the shower with insulated tubing. Sized roughly at 1 kW per 50 cubic feet of stall enclosure (industry standard); typical residential units are 7 to 12 kW on 220 to 240V.
- Sealed stall. Standard shower enclosures with open tops are NOT steam-rated. The stall must be fully sealed with a top closure (ceiling, transom panel, or top-cap glass) to retain steam.
- Sloped ceiling. Typically 1/2 inch per foot away from the steam outlet, so condensation drips run off to the side rather than dripping on the user.
Common 2026 brands include Mr. Steam, Steamist, Kohler Invigoration, and Amerec.
Electrically:
- Dedicated 240V or 120V circuit per manufacturer spec.
- GFCI required (NEC 680 / WAC 51-50).
Why it matters to a homeowner
Steam showers are luxury-tier remodels with luxury-tier costs:
- Steam generator: $1,200 to $4,000.
- Sealed enclosure with steam top-cap: $2,000 to $6,000.
- Pro install (electrical plus plumbing plus sealing): $3,000 to $10,000+.
Two ongoing considerations:
- Maintenance. Steam generators accumulate scale internally; auto-flush features help, but manual flush 1 to 2 times a year is standard. Hard-water service areas in WA accelerate scale.
- Sealing reliability. A sealed stall fails to hold steam if the door gasket, top closure, or wall waterproofing degrades. Steam migrating into adjacent rooms is the warning sign — addressed by re-gasketing or re-sealing the enclosure.
For a pre-purchase home with an existing steam shower, verify the generator runs, check for visible scale on accessible components, and ask the seller for service-history records.
Common failure modes
- Steam generator scale buildup. Auto-flush features help; manual flush 1 to 2x per year required for hard water.
- Improper stall sealing. Steam escapes; condensation in adjacent rooms.
- Underspec’d generator for stall volume. Never reaches steam temperature.
- Dripping ceiling. Slope wrong direction or none at all.
Common variants
- Steam shower (electric steam generator, this entry) vs. sauna (dry heat from a heated rock element; separate concept).
- Integrated steam-shower kit vs. custom-built sealed steam shower.
- 120V generator (smaller stalls) vs. 240V generator (larger stalls).