The tile and materials you choose for a steam shower do more than define how it looks — they affect how the generator performs, how much energy the system uses, how long everything lasts, and in some cases which generator size you need. This guide covers every material option from porcelain to natural stone, what to avoid and why, and everything you need to know about the enclosure itself before you build or renovate.
TheSteamStore.com is an authorized dealer of Mr. Steam, ThermaSol, and Amerec. If you have questions about how your tile choice affects your generator selection, contact our team — we will help you spec the right system for your space.
Why material choice matters more in a steam shower than a regular shower
A standard shower runs for 8–10 minutes and involves water flowing over surfaces. A steam shower fills a sealed enclosure with near-100% humidity at 110–120°F for 15–20 minutes or longer. The materials in that enclosure are not just getting wet — they are being saturated with hot vapor repeatedly, every day, for years.
Two properties determine how well a material performs in a steam environment:
- Porosity — how much moisture the material absorbs. High porosity materials absorb steam, which causes two problems: they act as heat sinks that make the generator work harder to maintain temperature, and they hold moisture that can lead to mold, mildew, and structural damage over time
- Thermal stability — how well the material handles repeated cycles of heat and humidity. Materials that expand and contract significantly with temperature changes will cause grout cracking, tile shifting, and eventually substrate failure
This is also why wall material directly affects generator sizing for some brands. Mr. Steam and Amerec apply a 1.75 multiplier to the base cubic footage when natural stone is used — stone's heat absorption means the generator has to work harder to reach and maintain temperature. ThermaSol's sizing formula is based on cubic footage only and does not require a material adjustment regardless of wall type.
Materials that work well
Porcelain tile — the best all-around choice
Porcelain tile is defined by ANSI as an impervious tile with a water absorption rate of 0.5% or less — the lowest of any tile category. It retains heat efficiently, reflects steam back into the space rather than absorbing it, and requires essentially no maintenance beyond regular cleaning. It is also the most versatile option aesthetically: modern porcelain is available in formats that convincingly replicate marble, stone, wood grain, and concrete — giving you the visual appeal of premium materials without their maintenance burden in a steam environment.
For floors, look for porcelain with a slip resistance rating of A or B. Some manufacturers offer an R-11 finish that adds slip resistance without changing the tile's appearance — a good option for steam shower floors where the surface is always wet.
Large format porcelain (24×24" or larger) is popular for steam showers because it minimizes grout lines, which reduces maintenance and gives a cleaner, more spa-like appearance. The trade-off is that larger tiles require more precise substrate leveling and a very flat floor or wall surface.
Glazed ceramic tile
Glazed ceramic has a higher absorption rate than porcelain (up to 3%) but the glaze surface itself is non-porous, which makes it acceptable for steam shower use when a quality waterproofing system is installed underneath. It is a practical, cost-effective option for a steam shower that does not need to be the premium choice. Unglazed ceramic is not suitable for steam shower use — the porous body will absorb moisture.
Glass tile
Glass tile is non-porous, heat-resistant, and reflects light beautifully — making steam showers feel larger and more luminous. It is an excellent choice for accent walls, niches, and feature areas within a steam shower. Glass tile can also be used for full wall coverage, though it requires a skilled installer since it is less forgiving than ceramic or porcelain during installation. Use a white or light-colored non-sanded grout with glass tile to avoid scratching the tile surface during grouting.
Solid surface and acrylic panels
Solid surface materials (Corian, Swanstone, and similar products) and acrylic panels are grout-free, seamless, and completely non-porous — making them highly practical for steam showers from a maintenance standpoint. They are particularly useful for ceilings, where grout maintenance is most difficult. The aesthetic is more utilitarian than tile, which makes them more common in commercial applications than high-end residential steam showers.
Natural stone — beautiful but demanding
Natural stone is one of the most requested materials for steam showers, and it can be used successfully — but it requires more planning, more maintenance, and a larger generator for Mr. Steam and Amerec installations. Here is how each stone type performs:
Granite and quartzite — the best natural stone options for steam showers. Both are dense, hard, and relatively low porosity compared to other natural stones. They handle heat and humidity better than softer stones and require resealing less frequently — typically once a year with a penetrating sealer. If a client insists on natural stone, granite or quartzite is the recommendation.
Marble — popular and beautiful, but the most demanding natural stone option in a steam environment. Marble is relatively porous and sensitive to the acidic condensation that forms in steam enclosures. It requires rigorous sealing with a penetrating sealer, pH-neutral cleaning products, and more frequent maintenance than other options. Used in high-end steam showers across the world — including with all three brands we carry — but the client needs to understand and commit to the maintenance requirements.
Slate and bluestone — moderate porosity, good thermal stability. A practical middle ground between granite and marble. Requires sealing but is more forgiving than marble in a steam environment. The naturally textured surface provides inherent slip resistance, which is a practical advantage for floors.
Travertine and limestone — generally not recommended for steam showers. Both are highly porous, soft, and particularly sensitive to moisture and acidic condensation. If a client loves the look of travertine, a travertine-look porcelain tile is a far better choice for a steam environment.
Natural stone and generator sizing: If you choose natural stone for your steam shower walls, multiply the enclosure's cubic footage by 1.75 before selecting a Mr. Steam or Amerec generator. For example, a 4×5×8 ft shower (160 cu ft) with marble walls becomes 280 cu ft for generator sizing purposes. ThermaSol's sizing formula is based on cubic footage only — no material adjustment required regardless of wall type.
Materials to avoid entirely
Wood. The most common request and the clearest no. Wood absorbs moisture, swells, warps, and rots under repeated steam exposure. What looks like a stunning design statement will be a mold and structural problem within a year or two of regular steam use. If a client wants the warmth and grain of wood in their steam shower, wood-look porcelain tile is the correct solution — the visual result is nearly identical and will outlast the house.
Standard drywall. Never use standard drywall anywhere within a steam shower enclosure — not even as a substrate behind tile. Steam penetrates tile grout and the substrate beneath it. Standard drywall will absorb moisture, lose structural integrity, and develop mold. Cement board or a dedicated waterproof membrane system is required on all surfaces.
Concrete. Poured concrete and concrete board are porous and not suitable as finish surfaces inside a steam shower enclosure. Concrete tile (a porcelain product designed to look like concrete) is fine — actual concrete is not.
Brick. Porous and rough-surfaced — absorbs moisture and traps debris. Brick-look porcelain tile handles both problems and is suitable for steam shower use.
Unglazed ceramic. The porous body will absorb moisture even if the surface appears sealed. Use only glazed ceramic in a steam environment.
Material comparison at a glance
| Material | Steam shower suitable | Generator sizing impact | Maintenance level |
|---|---|---|---|
| Porcelain tile | Yes — ideal | No adjustment needed | Low |
| Glazed ceramic tile | Yes — with proper waterproofing | No adjustment needed | Low |
| Glass tile | Yes — excellent | No adjustment needed | Low |
| Solid surface / acrylic | Yes — grout-free and seamless | No adjustment needed | Very low |
| Granite / quartzite | Yes — with annual sealing | 1.75× multiplier for Mr. Steam and Amerec | Moderate |
| Marble | Yes — with rigorous maintenance | 1.75× multiplier for Mr. Steam and Amerec | High |
| Slate / bluestone | Yes — with regular sealing | 1.75× multiplier for Mr. Steam and Amerec | Moderate |
| Travertine / limestone | Not recommended | — | Very high |
| Wood | No — avoid entirely | — | — |
| Concrete (poured) | No — avoid entirely | — | — |
Enclosure requirements: what the space itself needs
The tile is only part of the equation. The enclosure itself has specific structural and construction requirements that must be met before any tile goes up.
Waterproof substrate. Every surface inside a steam shower — walls, floor, and ceiling — must have a waterproof substrate behind the tile. Cement board (Durock, Hardiebacker, and similar products) is the most common choice, but a dedicated waterproof membrane system (Schluter KERDI, Laticrete Hydro Ban, and similar) provides a higher level of protection and is preferred for steam shower applications. Standard drywall — including moisture-resistant green board — is not acceptable as a steam shower substrate.
Sloped ceiling. The ceiling must slope a minimum of 2 inches per foot toward one wall to drain condensation. A flat ceiling in a steam shower causes condensation to drip cold water on bathers during a session — one of the most common and avoidable complaints. On curved ceilings, use smaller tile formats that conform more easily to the curve. For sloped ceilings, the tile does not need to follow the slope — a flat tile layout on a sloped ceiling surface is fine.
Sealed door and enclosure. The shower must be fully enclosed with a door that seals tightly when closed. Even small gaps at the door — under a frame, around a threshold, at hinge points — allow steam to escape, which reduces the enclosure's efficiency and makes it harder for the generator to maintain temperature. Frameless glass doors with magnetic or compression seals are the most effective and most visually appealing option for a steam shower.
Minimum enclosure size. The minimum practical size for a steam shower is 3×3 ft. Anything smaller is difficult to move in and can cause discomfort from steam that feels too intense in a very confined space. Most residential steam showers run 4×4 ft or larger, with 4×5 ft being a common and comfortable size for a single-person steam shower.
Bench seating. A bench is strongly recommended for steam shower use — sitting down during a 15–20 minute steam session is significantly more comfortable than standing. Benches should be constructed from non-porous, steam-compatible materials. Tile-covered concrete or tile-covered cement board is the most practical and durable choice. Position the bench on the wall opposite the steamhead so steam fills the space before reaching the seated bather.
Steamhead placement. The steamhead should be installed low on the wall — typically 6–12 inches from the floor — on the wall opposite the bench and opposite the door. Low placement allows steam to rise naturally and fill the space evenly. Never install the steamhead directly above the bench or directly adjacent to the control — steam blowing directly onto either creates discomfort and inaccurate temperature readings.
Ventilation. Do not install an exhaust fan that runs during the steam session — it pulls steam out of the enclosure. A timer-controlled exhaust fan that activates after the session ends is the correct approach for managing humidity in the bathroom after the steam session is complete.
Grout selection
Grout is a critical and often overlooked part of a steam shower installation. Standard sanded grout is porous and will absorb moisture in a steam environment. Use one of the following:
- Epoxy grout — non-porous, impervious to moisture, stain-resistant, and requires no sealing. The most durable choice for a steam shower. Harder to work with during installation — use an experienced tile installer
- Urethane grout — pre-mixed, non-porous, and easier to work with than epoxy. A good middle-ground choice for steam shower applications
- Cement-based grout with penetrating sealer — acceptable but requires resealing annually. The least preferred option for a steam shower where grout is under constant moisture exposure
For glass tile specifically, use a non-sanded grout regardless of type — sanded grout will scratch the glass tile surface during installation.
Frequently asked questions
Can I use marble in my steam shower?
Yes — marble can be used in a steam shower successfully, but it requires more maintenance than porcelain or ceramic tile. It must be sealed with a penetrating sealer before use and resealed every 6–12 months depending on use frequency. Clean only with pH-neutral products — acidic cleaners will etch the marble surface. If you love the look of marble but want less maintenance, a marble-look porcelain tile is a practical and visually comparable alternative. Note that marble walls require a 1.75× cubic footage multiplier when sizing a Mr. Steam or Amerec generator.
Does my tile choice affect which generator I need?
Yes — for Mr. Steam and Amerec generators, natural stone walls (marble, granite, slate, travertine) require multiplying the enclosure's cubic footage by 1.75 before selecting a generator model. ThermaSol's sizing formula is based on cubic footage only and does not require a material adjustment regardless of wall type. See our steam generator sizing guide for a complete walkthrough.
Can I use large format tile in a steam shower?
Yes — large format porcelain tile (24×24" and larger) is a popular choice for steam showers because fewer grout lines means less maintenance and a cleaner look. Large format tile requires a very flat, well-prepared substrate — any variation in the wall or floor surface will be visible. Have the substrate checked with a straightedge before tile installation begins.
Do I need to seal porcelain tile in a steam shower?
No — porcelain tile with a water absorption rate of 0.5% or less does not require sealing. The tile surface itself is impervious. The grout between tiles may need sealing depending on the type used — epoxy and urethane grout do not require sealing, cement-based grout does.
Why does my ceiling need to be sloped in a steam shower?
Steam rises and condenses on the ceiling as it cools. Without a slope, condensation collects and drips as cold drops onto bathers — one of the most common complaints about poorly built steam showers. The minimum slope is 2 inches per foot toward one wall, which channels condensation down the wall rather than allowing it to drip from above.
Can I convert my existing shower into a steam shower?
Yes — if it is fully enclosed with a sealed door, has a minimum 3×3 ft floor area, and the enclosure can be confirmed watertight. The substrate behind existing tile must also be waterproof — if the original shower was built with standard drywall behind the tile, a steam conversion requires demolition and proper waterproofing before the generator is installed. See our steam shower installation requirements guide for everything that needs to be confirmed before a conversion.
Ready to build or upgrade your steam shower?
Browse steam generators by brand and find the right system for your enclosure:
- Mr. Steam generators — the broadest residential lineup, covering 60 to 900+ cubic feet
- ThermaSol PRO Series III generators — patented Smart Steam technology, no material sizing adjustment required
- Amerec generators — Sequential Temperature Control, ETL listed for USA and Canada
Use our steam generator sizing tool to find the right model for your space, or contact our team and we will size it for you. Call us at 877-881-5501 Monday through Friday.