Bathroom Tiles — Floor and Wall Specification

Floor first: slip rating is the specification

Specify a minimum of R10 for a bathroom floor and R11 for a shower floor or a wet room. These ratings are measured on a lubricated ramp, which is the relevant condition — almost any tile grips well dry. A polished PGVT looks superb in a bathroom showroom and is genuinely dangerous once someone steps out of a shower onto it.

Smaller tiles help on a shower floor, and not only for grip. A shower tray area needs a fall towards the drain of around 1 in 50, and you cannot build a fall into a large rigid tile. Mosaics or 100 mm to 300 mm tiles let the setter follow the slope. The extra grout lines are a bonus here rather than a compromise: grout is a much higher-friction surface than glaze.

Everywhere else in the bathroom, larger is better. Fewer grout lines means less to clean, fewer places for mould, and a floor that reads as a continuous surface rather than a grid — which makes a small bathroom look larger, not smaller. The advice that small rooms need small tiles is simply wrong.

GVT & PGVT range · Tile size guide

What to specify

Bathroom detailing that prevents callbacks

• Tank before you tile — tiles and grout are not a waterproof layer. A wet area needs a membrane behind the tile, taken up the walls and into the tray.
• Silicone the internal corners — wall-to-wall and wall-to-floor junctions move. Grout there will crack; a flexible sealant will not.
• Use an epoxy grout in the shower — it does not absorb water and will not discolour or grow mould the way cementitious grout does.
• Mitre the external corners — a mitred porcelain corner reads far better than a plastic trim, and on a full body tile the joint is invisible.
• Plan the tile layout around the fittings — set out so cut tiles fall at the least visible edge, not beside the basin.
• Order sanitary ware with the tiles — shipping them in the same container cuts the freight cost per unit substantially.

Frequently asked questions