What tiles to avoid in a shower
Look, picking the wrong tile for your shower? That's a headache you don't want. We're talking expensive fixes, constant scrubbing, and honestly—safety nightmares. Sure, that marble looks gorgeous in the showroom, but a shower's basically a steam room meets a slip-and-slide. So let's get real about what tiles are just asking for trouble.
Why is natural stone tile often a bad choice for showers?
Natural stone—marble, travertine, slate, limestone—they're all porous. Like, really porous. Water just soaks right in. Then you've got stains, etching from your shampoo, and mold growing inside the stone itself. Gross. You can seal it, sure, but those grout lines and natural cracks? Impossible to keep fully waterproof forever. Eventually the stone degrades, changes color, and you're stuck paying for professional restoration. Some dense granite might work, but honestly? Most soft, porous stones are just asking for maintenance headaches.
Which glazed ceramic and porcelain tiles should be avoided?
Here's the thing—not all ceramic or porcelain is created equal. You gotta check water absorption and surface texture. Avoid these specifically:
- High-absorption ceramic tiles: Those standard wall tiles? They can soak up more than 3% water. In a shower, that means moisture gets in, glaze peels off, and the tile body literally crumbles. Stick with porcelain or certified impervious ceramic.
- Glossy, polished porcelain tiles: Technically waterproof, yeah. But wet? They're like ice. Soap scum makes it worse. Seriously dangerous for floors.
- Unglazed or matte finish tiles with poor slip resistance: Don't assume matte equals safe. Check for a Coefficient of Friction (COF) of 0.6 or higher. Smooth matte surfaces? Still slippery.
Can you use glass tiles in a shower?
Glass tiles? Gorgeous. Non-porous. Great for walls. But you gotta dodge certain types for safety and durability:
- Clear or transparent glass tiles over a dark substrate: Every imperfection shows. Water stains, mold—it's all visible. Plus they crack if the wall shifts even a little.
- Glass tiles with metal or foil backing: Look pretty, but moisture and cleaning chemicals corrode that metal. Ruins the whole look fast.
- Small, heavily textured glass mosaics: All those grout lines between tiny pieces? Nightmare to clean. Soap scum and mold love hiding there.
What about large-format tiles? Are they a problem?
Big tiles—24x48 inches or whatever—they're trendy. But risky in showers. Avoid them if:
- Your shower floor is not perfectly flat: Large tiles need a perfectly sloped base. If it's off, the tile rocks or cracks, and water pools.
- You use them on a shower floor: Getting proper drainage slope with huge tiles? Almost impossible. You need a linear drain plus a complicated mud bed. Otherwise you get "birdbaths"—standing water.
- You cannot achieve proper drainage slope: Small tiles—1x1 or 2x2 inches—conform easily to slopes. Large tiles on a floor? Major red flag for poor drainage.
Data Table: Shower Tile Risk Assessment
| Tile Type | Risk Level | Primary Issue | Recommendation |
|---|---|---|---|
| Marble / Travertine (natural stone) | High | Porous, stains, etches, needs constant sealing | Avoid for walls and floors; use only in low-moisture areas |
| Polished porcelain (glossy) | High | Extremely slippery when wet | Avoid for floors; okay for walls if slip not a concern |
| High-absorption ceramic (wall tile) | High | Absorbs water, delaminates, grows mold | Avoid entirely; use only impervious porcelain |
| Large-format tile (on floor) | Medium-High | Poor drainage, water pooling | Avoid on floor; use small mosaics for proper slope |
| Glass tile with metal backing | Medium | Corrosion, tarnishing, delamination | Avoid in wet areas; use solid glass or ceramic |
| Unglazed quarry tile | Medium | Porous, stains easily, difficult to clean | Avoid; use glazed porcelain instead |
Checklist: How to Choose a Safe Shower Tile
Before you drop cash, run through this. Save yourself some regret:
- Check water absorption: Look for "impervious" (less than 0.5% absorption). Porcelain's your best bet.
- Test slip resistance: For floors, COF of 0.6 or higher. Matte or textured beats glossy every time.
- Verify slope compatibility: Shower floors? Stick to tiles 2x2 inches or smaller. Big tiles need a pro and a linear drain.
- Avoid porous stone: Marble, travertine, slate—high maintenance. If you insist on stone, go dense granite and seal it perfectly.
- Inspect glass tile backing: No metal or foil backs. Solid glass or ceramic-backed glass is safer.
- Consider grout width: Tiny mosaics = more grout lines = harder to clean. Bigger tiles (6x6 or 12x12) mean less grout.
- Ask for a sample: Wet it, add soap, feel how slippery it gets. Don't skip this.
Frequently Asked Questions
Is porcelain tile always safe for a shower?
Not always. Porcelain's waterproof, sure, but surface finish matters. Glossy or polished? Dangerous on floors—slippery as hell. Choose matte, textured, or satin finish for floors. And make sure it's rated for floor use, not just wall.
Can I use subway tile in a shower?
Yeah, subway tile works great if it's glazed ceramic or porcelain with low water absorption. But for floors? Don't use standard rectangular subway tile—it doesn't slope well. Stick with small square mosaics or hex tiles for the floor.
What is the best tile for a shower floor to avoid slipping?
Small-format porcelain or ceramic mosaics—1x1 or 2x2 inches. Or textured stone-look porcelain. Look for COF of 0.6 or higher. Pebble tiles? Super slip-resistant but uncomfortable on bare feet. Just avoid anything smooth, glossy, or polished.
How do I know if a tile is waterproof enough for a shower?
Check the water absorption rating. "Impervious" (less than 0.5%) or "vitreous" (0.5% to 3%) are fine. Avoid "semi-vitreous" (3% to 7%) and "non-vitreous" (over 7%) for shower walls and floors. Porcelain's usually impervious; many ceramics aren't.
Are penny rounds good for shower floors?
Penny rounds—those small circle tiles—are popular because they conform well to slopes. But tons of grout lines means more cleaning. They're slip-resistant but can be uncomfortable on bare feet. Good choice if you're okay with regular grout maintenance.
Short Summary
- Avoid porous natural stone: Marble, travertine, and slate absorb water, stain easily, and require high maintenance in a shower.
- Skip glossy and polished finishes: These become dangerously slippery when wet, especially on shower floors.
- Beware of high-absorption ceramic: Standard wall tiles can absorb moisture and delaminate; always choose impervious porcelain.
- Large tiles on floors are risky: They prevent proper drainage and can cause water pooling; use small mosaics for sloped floors.
