Bathroom Tile: A Buyer's Guide to Every Surface

A bathroom has four tile surfaces, and each asks for something different. The floor is walked on wet and barefoot. The shower walls are soaked every day but never stepped on. The shower floor is both. Accent areas, like a vanity wall or a niche, only have to look good and wipe clean. Most tile disappointments come from choosing one tile for the room on looks alone, then finding it is too slippery underfoot or too porous for the shower.

This page is the starting point for the tile section. It covers what each surface needs, the materials at a glance, the numbers on a spec sheet, and how to order. The deeper pages are linked as you go.

What each surface needs

Start with the surface, then pick the tile. The table below is the short version.

Behind every wet surface, the tile is only the finish. The water protection comes from the membrane or board system underneath, which is covered in bathroom waterproofing explained. Washington's residential code also requires shower and tub walls to have a nonabsorbent surface to at least 6 feet above the floor, so tile has to go at least that high around a shower.

The materials at a glance

Each of these has its own page. Here is how they compare in a bathroom.

For the full porcelain and ceramic comparison, see porcelain vs ceramic tile. Marble, travertine and other stone are on natural stone in bathrooms, and handmade and glass accents on zellige and handmade tile.

Reading a tile spec sheet

A showroom sample tells you color and texture. The spec sheet tells you whether it belongs on your floor. These are the lines that matter in a bathroom.

Water absorption

The Tile Council of North America (TCNA) defines porcelain as impervious tile with water absorption of 0.5 percent or less, measured by ASTM C373. Tile labeled porcelain is not always tested to that line. The Porcelain Tile Certification Agency (PTCA) tests tile independently, and certified tile can carry the PTCA mark on the box. The general ceramic tile standard is ANSI A137.1 (2022 edition).

Slip resistance (DCOF)

ANSI A326.3 (2021 edition) is the test for dynamic coefficient of friction, or DCOF, on hard flooring. It sorts products into use categories. For a bathroom floor, look for Interior, Wet (IW), which requires a wet DCOF of 0.42 or more, or a maker's declaration. TCNA cautions that DCOF does not predict whether a particular person will slip, so a matte or textured surface and good habits still matter.

The standard's text on shower floors could not be confirmed for this guide, so do not rely on a single number there. In practice, shower floors use small mosaics, because the many grout joints add grip and the small pieces follow the slope to the drain.

Size, edges and finish

• Rectified or calibrated. Rectified tile has its edges ground after firing, so pieces are very close in size and can take narrower joints. Calibrated tile is sorted by size but not ground, and needs wider joints.
• Nominal size. Once any side is longer than 15 inches, stricter rules apply to offsets and joint widths. See large-format and slab tile.
• Finish. Polished, honed, matte and textured. Polished looks wet even when dry and is the slipperiest when actually wet.
• Shade variation. Makers rate how much one piece differs from the next. A high-variation tile needs boxes blended during installation.
• Lot numbers. Shade and caliber are printed on the box. Every box for one surface should share them.

How much to order

Order for the layout, not the square footage. The waste depends on the pattern, the room's shape, the tile size and how many cuts land at niches, windows and the shower curb. A straight stacked layout in an open floor wastes the least. Diagonal, herringbone and chevron patterns waste noticeably more, as explained in tile patterns and layouts. Small bathrooms often waste a larger share, because most of the floor is cut pieces.

Two habits save trouble later. Order everything from one lot at once rather than topping up, because a second order rarely matches. And keep a spare box, labeled with the lot numbers, so a cracked tile can be replaced after the line is discontinued.

Grout is part of the tile choice

Grout changes how tile looks and how it ages. A matching grout makes a wall read as one surface; a contrasting one draws every line. Cement grout is not waterproof and stains if it is not sealed, while epoxy and pre-mixed grouts behave differently. Choose the grout type and color while you choose the tile, using grout and sealing for bathrooms.

What to check before you buy

1. The spec sheet allows the tile where you plan to use it: floor, wall, shower wall, shower floor.
2. Floor and shower floor tile carry a wet slip classification (Interior, Wet or higher) from the maker.
3. If it is sold as porcelain, check for the PTCA mark or a test result showing 0.5 percent absorption or less.
4. All boxes share one shade and caliber lot, and you have seen at least several pieces together, not one sample.
5. Any side over 15 inches: your installer has a plan for the offset, joint width and floor flatness.
6. Trim exists for the edges: bullnose, metal edge profiles or finished pieces for the niche and outside corners.
7. The grout type and color are chosen and tested on a spare tile, especially for stone and handmade tile.
8. You have ordered the overage your installer calculated, plus a spare box to keep.
9. Delivery is timed so tile is on site before demolition, so a backorder does not leave the bathroom open.

How JDI handles tile

At JDI, tile is chosen during design, before construction is scheduled. Denise Lacquement, our bathroom designer, walks through the surfaces with you and the 3D layout shows where cuts and grout lines fall. Tile and waterproofing are part of every bathroom remodel we build in Vancouver, so the person choosing the tile and the team installing it are working from the same plan. If you are weighing a quick refresh instead, our post on whether bathroom tile can be painted covers the trade-offs.