How Do You Clean a Steam Shower and Keep Mold Under Control?

Published September 27, 2026

Summary

A steam shower is cleaned much like a heavily used shower: remove soap film, rinse the surfaces, and help the enclosure dry after use. The difference is that steam reaches the ceiling and upper walls as well as the normal splash zone. Drying and sound waterproofing do more against mold than aggressive cleaners. If mold returns quickly, the problem may be moisture or construction rather than a dirty surface.

Drying is part of the cleaning routine

MrSteam suggests running cold water for 15 to 30 seconds after a steam session, then clearing the leftover humidity with an exhaust fan outside the enclosure or an operable transom. Delta's build guide adds that leaving the door open lets air in to dry the shower and prevent mildew.

MrSteam's daily routine is the same as for any shower: squeegee or towel the glass, and clean the surfaces with mild soap and water.

Use a cleaner that matches the surface

A steam shower can contain natural stone, grout, metal trim, coated glass, acrylic, or other materials, and they do not all tolerate the same chemicals.

The Natural Stone Institute warns that products with lemon, vinegar, or other acids may dull or etch calcareous stone such as marble and limestone, and recommends a neutral cleaner, stone soap, or mild dishwashing detergent. EnduroShield, which makes a coating for shower glass, rules out gritty, abrasive, highly acidic, or alkaline cleaners on coated glass, yet suggests diluted white vinegar for tile and grout. In a shower with marble walls and coated glass, those instructions have to be kept apart.

Look up, not just down

Steam puts condensation on the ceiling and upper corners, which an ordinary shower barely wets. Delta's guide notes that a sloped ceiling does not always stop drips, because water may fall at a tile edge instead of running down the slope.

Include those surfaces in routine inspection. Waiting until staining appears can make it harder to tell whether the problem is simple surface buildup or moisture that has been lingering for too long.

Mold that keeps returning deserves more than another cleaning

Repeated mold growth can point to cracked sealant, failed grout, poor drying, hidden leakage, or a problem in the waterproofing system.

The EPA's mold guidance says that if the mold is cleaned up but the water problem is not fixed, the mold will most likely come back. It also says not to paint or caulk over moldy surfaces.

The generator is a separate maintenance job

Cleaning tile and glass does not flush or descale the steam generator.

Surface care follows the materials in the shower; the generator has its own procedure in the equipment manual.

Sources

Specifications, prices and installation requirements are as the makers published them on these pages on the date above and can change. Check the current manual and the retailer before you buy.