Tile a Bathroom: The Complete Project Guide

1. Waterproof the substrate before anything else

Standard drywall has no place in a wet bathroom area — cement board, fiber-cement backer board, or a foam waterproofing panel system is the substrate tile actually gets set on in a shower or tub surround, and a liquid or sheet waterproofing membrane goes over seams and any penetrations (like a shower valve or drain) before tile touches it. Floors need their own waterproofing membrane, especially around the drain, since a floor without one lets moisture wick into the subfloor over years of daily use even if the grout looks fine on the surface.

This step has its own cure time (check the specific membrane product) that has to be respected before tile setting starts — rushing it is exactly the kind of shortcut that shows up as a leak or mold problem well after the visible tile work is done and looks great.

2. Plan the layout before you set a single tile

Measure the room per how to measure a room for tile, which covers irregular shapes like the alcoves and jogs common in bathrooms. Dry-lay a row or two of tile (without adhesive) to check where cut pieces will fall — centering the layout so you get roughly even cut widths on opposite walls looks far better than starting flush against one wall and ending with an awkward sliver at the other.

Run the tile calculator with your chosen pattern's waste percentage — bathrooms often have more cuts per square foot than a simple rectangular room because of toilets, vanities, and tub/shower transitions, so err toward the higher end of your pattern's typical waste range.

For a shower wall specifically, plan vertical layout so the pattern lands on a full or evenly-sized cut row at eye level rather than an odd sliver — this is more work upfront than a floor layout, where an uneven row along a baseboard is far less noticeable than one at eye height in a shower.

3. Set tile with the right thinset for the substrate

Use the grout & thinset calculator to size thinset by trowel notch and grout by joint width/depth — these follow different formulas from each other and from the tile count itself. On a shower wall, back-buttering larger tiles (applying thinset to the tile back as well as the wall) in addition to trowel-combing the wall gives better full-contact support, which matters more in a constantly wet environment than it does on a dry interior wall.

4. Grout only after full thinset cure

Thinset needs to fully cure (typically 24-48 hours, check the product) before grouting — grouting too early can disturb tiles that haven't fully set. Use sanded grout for wider joints and unsanded for narrow ones, and seal grout in wet areas per the product's recommendation, since unsealed grout in a shower absorbs water and can support mildew growth over time.

Silicone caulk (not grout) belongs in the corner joints where tile meets tile at a change of plane (wall-to-wall, wall-to-floor, wall-to-tub) — rigid grout in a moving joint like that will crack as the structure flexes slightly with temperature and humidity changes.

5. Fixtures and the drain

The toilet is typically removed before tiling (and reset afterward on a new wax ring) so tile can run cleanly under and around the flange rather than being cut awkwardly around a fixture that stays in place — this also gives a cleaner, more finished look than tiling up to a toilet base. A shower drain needs to sit at exactly the right height relative to the finished tile surface, with the surrounding floor sloped slightly toward it (typically about a 1/4 inch per foot slope) so water actually drains rather than pooling — this slope has to be built into the mortar bed beneath the tile, not corrected after the fact.

6. Niches, benches, and other built-ins

A shower niche or built-in bench needs to be framed and waterproofed as part of the substrate step, not added afterward — the niche's interior surfaces (back, top, bottom, sides) all need the same waterproofing membrane treatment as the main shower walls, and the small enclosed space generates more cuts per square foot than the surrounding wall, so it's worth measuring and budgeting for separately rather than folding it into the general wall waste percentage.

A bench, if built in, needs its own slight slope toward the shower drain (or its own small drain in some designs) so water doesn't sit on the seat surface, following the same drainage-slope principle as the floor.

Tools and materials checklist

• Cement or fiber-cement backer board (or a foam waterproofing panel system) plus the fasteners and seam tape specified by that system's manufacturer.
• Liquid or sheet waterproofing membrane rated for the specific substrate and application (shower pan, wall, or floor).
• A wet tile saw for straight cuts and a tile nipper or angle grinder for smaller notches around fixtures and pipes.
• Trowels sized to the tile (per the grout & thinset calculator), tile spacers for consistent joint width, and a rubber grout float.
• Sanded or unsanded grout matched to joint width, grout sealer for wet areas, and 100% silicone caulk (not grout) for change-of-plane corners.
• A laser level or standard level for checking wall plumb and floor slope before and during tile setting.

7. Trim, edging, and finishing details

Tile edges at an outside corner (like where a tiled tub surround wall meets an untiled wall) need either a mitered tile edge, a metal or plastic edge trim (bullnose profile or a Schluter-style strip), or a bullnose tile specifically made for that purpose — deciding which finish to use before setting the field tile matters, since it affects how the tile layout is planned to meet that edge cleanly rather than being figured out as an afterthought.

A separate accessory shelf, niche shelf, or grab bar blocking (wood backing installed in the wall before waterproofing, for a future grab bar) are both easy to add during the substrate stage and considerably harder to retrofit once tile is set — worth deciding on during the planning phase even if not installed immediately.