How Do You Tile a Bathroom?

Waterproofed backer board first, a squared layout second, tile third. Skip either of the first two and the third one looks fine for about a year. Bathrooms punish shortcuts faster than any other room in the house, small and wet with more fixtures to cut around than a kitchen or a hallway ever has. Here’s the order that actually holds up, floor and walls both.

Where Do You Start Tiling a Bathroom?

Not at the door, and not against the first wall that looks straight. Find the room’s most visible line of sight first, usually the doorway looking straight in, and work the layout so full tiles land there rather than a sliver cut. Dry-lay a row of tile with spacers along the two longest walls before any mortar goes down, checking where the cut pieces fall at the corners and around the tub or vanity.

Floors start from a snapped chalk line through the room’s centre, not from a wall. Walls behind a tub or shower start from a level line set up from the tub rim, since tub rims are rarely level themselves, and tiling to a level reference line beats tiling to a rim that’s out by a quarter inch on one end. Get that starting line wrong and every tile after it carries the error a little further, which is exactly why the next step matters more than most first-time tilers expect.

What Do You Put Under Tile in a Bathroom?

Cement backer board over a wood subfloor, screwed down every six to eight inches into the joists below, not just into the subfloor layer. Seams get taped with mesh tape and a skim coat of thinset before any floor tile touches them. Skip that step and the seam telegraphs through as a hairline crack in the grout within a year or two, sooner in a bathroom that sees daily foot traffic.

Shower walls and any surface that sees direct water need a waterproof membrane over the backer board, not just the backer board on its own. Cement board resists water better than drywall, but it isn’t waterproof by itself; the membrane, whether it’s a liquid-applied coating or a sheet product, is what actually stops moisture from reaching the framing behind it. On a concrete slab, tile can bond directly to the concrete once it’s clean, level, and crack-isolated, no backer board required, though an uncoupling membrane still earns its cost on a floor with any hairline cracking already visible.

Tools and Materials for a Bathroom Tile Job

Notched trowel sized to the tile. Tile spacers, the wedge or leveling-clip kind for anything over 12 inches. Wet saw for straight cuts, angle grinder with a diamond blade for notches around pipes, tile nippers for small curves at a toilet flange. Level, both a torpedo and a 4-foot bar level. Grout float, mixing paddle, and a bucket that never sees anything but thinset once it’s dedicated to the job.

Backer board and screws, waterproof membrane for wet walls, thinset mortar, grout, and grout sealer round out the materials list. Buy 10 to 15 percent more tile than the square footage calls for, cut waste and future repairs both eat into that overage faster than most first-timers expect. Keep the box numbers when tile comes from more than one batch; dye lots shift colour slightly, and mixing them randomly across the floor spreads that variation instead of hiding it in one corner.

The 3-4-5 Rule for Squaring a Tile Layout

Almost nothing gets written about this, and it’s the single check that catches the most common layout mistake. Mark 3 feet along one wall from the corner. Then mark 4 feet along the adjoining wall from that same corner. The distance between those two marks tells the story: exactly 5 feet confirms a true 90-degree angle. Anything off by more than an eighth of an inch and the corner is out of square, which most bathroom corners are, at least a little.

Why it matters: tiling square to a wall that isn’t actually square produces grout lines that taper, wider at one end of the room than the other. Forgivable in a full-size room. A five-by-eight bathroom is where it shows first, standing right there in the doorway. Multiples of 3-4-5, like 6-8-10, work the same way and give more room for accurate measurement in a larger space. Check every corner the layout touches, not just the one nearest the door.

How to Install Tile in a Bathroom, Step by Step

Mix thinset to a stiff, non-slumping peanut-butter consistency, thin enough to spread but thick enough to hold a trowel ridge without collapsing. Spread with a notched trowel sized to the tile, typically a quarter-inch square notch for tile under 8 inches, a half-inch for larger format. Comb the mortar in one direction so air can escape as the tile seats.

Back-butter anything 12 inches or larger, a thin skim coat of thinset on the tile back in addition to the floor or wall, since large-format tile without back-buttering is where hollow spots and cracked corners come from later. Set each piece with a slight twist to work it into the ridges, keep spacers in until the mortar firms up, and check level every few tiles rather than at the end of a row. Cut tiles for the toilet flange, vanity base, and tub edge come last, using a wet saw for straight cuts and a nipper or hole saw for anything curved.

Let the thinset cure fully, usually 24 hours minimum, longer in a bathroom with poor ventilation, before grout goes in or before setting foot on a floor install.

Wall tile runs bottom to top off a temporary ledger board, a straight batten screwed to the wall at the height of one full tile above the tub or floor line. That ledger holds the first course level while the mortar sets, then comes out once the tile above it can carry its own weight, and the bottom row goes in last, cut to fit under the now-supported field. Skipping the ledger and stacking straight up from an uneven tub rim is how walls end up with a visible dip that only shows once the grout goes in and the eye has a joint pattern to follow.

Grouting and Sealing Bathroom Tile

Sanded grout for joints an eighth of an inch or wider, unsanded for anything narrower, worked in diagonally with a rubber float so the edge doesn’t drag grout back out of a joint it just filled. Wipe the haze off with a barely damp sponge about twenty minutes later, then again once it dries to a light film.

Seal the grout once it’s fully cured, typically 48 to 72 hours out. Bathrooms are the one room where sealing isn’t optional. Grout is porous, and a shower or tub surround sees direct water contact daily, so an unsealed joint starts absorbing moisture and staining within months. Reseal once a year on shower walls, every one to two years on a floor with lighter water exposure.

Common Mistakes to Avoid When Tiling a Bathroom

Skipping the waterproof membrane behind a shower wall tops the list, closely followed by grouting before the thinset has fully cured. Both show up as callbacks, not as install-day problems. Wrong trowel size for the tile format causes lippage, tiles sitting slightly proud of their neighbours, which is the number one complaint on large-format floor installs done with an undersized notch.

Setting the toilet flange at the wrong height relative to the finished tile is another one specific to bathrooms. The flange needs to sit level with, or very slightly above, the finished tile surface, not buried under it. Get that wrong and the toilet seal fails months later, usually showing up as a soft spot in the subfloor before anyone connects it back to the tile job. And skipping the 3-4-5 check because the corner “looks square” is the mistake behind almost every taper complaint that comes in after the fact.

Can You Tile a Bathroom Yourself?

Yes, for a straightforward floor with square corners and no shower surround involved. A small bathroom floor is a realistic first tiling project for someone comfortable with basic tools and willing to dry-lay everything twice before mixing mortar. Budget a full weekend for a floor alone, more if the subfloor needs backer board first. First-timers usually lose that time to the layout, not the setting, checking and rechecking dry-fit lines before committing to mortar.

The question that comes up once someone’s priced out a wet saw rental and a weekend of materials: is it actually cheaper than hiring it out. Materials alone for a small bathroom floor run a few hundred dollars in tile, thinset, backer board, and grout. Add a rented wet saw and the DIY total often lands within striking distance of a professional quote on a floor-only job, before factoring in a redo if the layout goes sideways. A full shower surround changes that math fast, since a licensed installer’s quote already prices in the waterproofing warranty that a DIY job doesn’t carry.

That surround is the harder call either way. Waterproofing that fails behind tile doesn’t show up for months, sometimes years, and by then the fix means tearing out tile, backer board, and sometimes framing to get at the leak. That’s the project where hiring makes sense even for someone who’d happily tackle the floor solo. Jordan Tile & Stone handles both, floor-only jobs and full bathroom installs, across Nanaimo, Victoria, Campbell River, and the surrounding Island communities. See the bathroom tile installation page for what a professional job covers, floor to ceiling, or get in touch with details on your specific space.

Planning the Layout So You Aren’t Fighting It Later

Dry-lay the tile before any adhesive touches the floor. Find the room’s centre point, snap chalk lines, and lay a full row out with spacers to see where the cuts land at the walls. A layout that puts a two-inch sliver of tile against the doorway looks wrong the moment it’s finished, and there’s no fixing it after the grout goes in.

Small adjustments to the starting point now save an entire re-tile later. Shift the layout so cut pieces land somewhere less visible, usually behind the door or under a vanity, rather than dead centre where every visitor’s eye lands first.

Frequently Asked Questions

Where do you start when tiling a bathroom?

From a squared reference line, not a wall. Floors start at a chalk line through the room’s centre; shower and tub walls start at a level line set off the tub rim, since rims are rarely level on their own.

What do you put under tile in a bathroom?

Cement backer board over wood subfloors, taped and skim-coated at the seams. Shower walls need a waterproof membrane over that backer board. Concrete slabs can take tile directly once level and crack-isolated.

What is the 3-4-5 rule for tiling, and why does it matter?

Mark 3 feet along one wall and 4 feet along the adjoining wall from the same corner. A 5-foot distance between those marks confirms a true 90-degree angle. Skip the check and out-of-square corners produce grout lines that visibly taper across the room.

What are the most common mistakes when tiling a bathroom?

Skipping waterproofing behind a shower wall, grouting before the thinset has cured, using the wrong trowel notch for the tile size, and setting the toilet flange too low relative to the finished tile.

Can I tile a bathroom myself?

A basic floor with square corners is a reasonable first project for someone willing to dry-lay the layout before mixing thinset. Full shower or tub surrounds are the higher-risk job, since a waterproofing failure doesn’t surface for months.

What’s the best way to lay tile in a bathroom, floor or walls first?

Floors typically go last, after wall tile and any shower niche work, so wall cuts land cleanly at the floor line instead of the floor tile dictating an awkward wall cut partway up.

Jordan Tile & Stone installs ceramic, porcelain, and natural stone bathroom tile across Vancouver Island. See the full bathroom tile installation service for pricing on a specific layout, or reach out with photos of the space to start.

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Jordan Tile & Stone

Tile installation and repair across central Vancouver Island: Campbell River, Courtenay, Comox, Oyster Bay, Nanoose Bay, Parksville, Qualicum Beach and Nanaimo.

Phone: (250) 201-3891
Hours: Monday to Sunday, 7:00 am to 6:00 pm
Address: 4423 Patricia Rd, Oyster Bay, BC V9H 1B8