Tile
Tiling a shower: every quantity, from walls to the floor
A shower is three walls, a floor, a niche, a curb and a lot of edges. Each has its own quantity, and the edges are the one people forget. Here is the whole list for a standard alcove.
What a shower is made of
A tiled shower is not one area but several. The walls, usually three, from the pan or tub to the top of the tile. The floor, sloped to the drain, in small mosaic. A niche recessed into the wall, whose back, top, bottom and sides are all tiled. A curb across the opening, tiled on three faces. And the edges: every exposed edge of tile needs a bullnose piece, a trim tile or a metal profile. Count each separately and add them.
The walls
Measure each wall’s width from corner to the opening, and the height from the pan or tub deck to where the tile stops. A full-height shower goes to the ceiling or to about 7 to 8 ft; a tub surround usually goes 5 to 6 ft above the tub. Multiply and add the walls. Do not subtract a niche: its back replaces the wall it is cut from, and its four sides are extra area on top.
The floor
Shower floors slope a quarter inch per foot to the drain, so they are tiled in small pieces that follow the slope: 2 × 2 inch mosaic on 12 × 12 inch sheets is standard. Count sheets from the floor area with 10% for cuts around the drain.
Under the mosaic goes the sloped base. A mortar bed is packed by hand to the slope, under or over a waterproof membrane, or a pre-sloped foam tray is set in thinset. A tray costs more than sand and cement but takes hours instead of a day and a cure, and it arrives with the slope and the drain already matched. Either way, the floor area for tile is the same, measured to the inside of the curb.
An alcove shower worked through
A 5 × 3 ft walk-in shower
Three walls, back 5 ft and sides 3 ft each, tiled 8 ft high in 24 × 12 inch tile with a 1/8 inch joint. A 12 × 24 inch niche, 3.5 inches deep, and a tiled curb.
- Walls: (5 + 2 × 3) × 8 = 88 sq ft
- Niche returns: 2 × (12 + 24) in × 3.5 in = 1.8 sq ft
- Curb: 5 ft × 16 in of tile around it = 6.7 sq ft
- Wall tile area: 96.4 sq ft ÷ 2.031 sq ft per tile = 47.5 tiles, plus 10% = 53 tiles, 7 boxes
- Floor: 5 × 3 = 15 sq ft, plus 10% = 17 mosaic sheets, 2 boxes
- Edges: 32 ft of exposed edge, plus 10% = 36 trim pieces
The shower tile calculator does all of this from the shower’s shape, and the wall tile calculator covers walls outside the shower.
The edges
Wherever the tile stops in open air there is an edge to finish: the front of each side wall, the top of the tile, the niche opening, the outer edge of the curb. There are three ways to finish them. Bullnose tile has one rounded, glazed edge. Trim pieces in the same series are sold by the piece. Metal profiles are sold by the length, typically 8 ft, and set in the mortar under the edge tile. Many large porcelain tiles have no matching bullnose, so profiles are common.
Behind the tile
Backer board. Cement or fibre-cement board on the walls, 1/2 inch thick, screwed every 8 inches. A tub alcove of about 96 sq ft takes 8 sheets of 3 × 5 ft board and about 320 screws. The cement board calculator counts them.
Waterproofing. Cement board is not waterproof. Behind it goes a vapour barrier, or in front of it a liquid or sheet membrane over the whole wet area, floor to above the shower head, with the seams and corners reinforced. Membrane makers give coverage per gallon or roll; two coats of liquid membrane typically cover 50 to 55 sq ft per gallon.
Mortar. Wall tile in a shower must reach 95% contact. With 24 × 12 tile, use a 1/2 inch notch and back-butter: the 96 sq ft of wall tile takes about 4 bags. The thinset calculator works it out, and the thinset guide explains why wet areas need more.
Grout and sealant
Showers get a lot of grout joint for their size, especially the mosaic floor. The grout calculator counts it separately for walls and floor because the joint and tile differ. Use a cementitious grout with a sealer, or an epoxy or urethane grout for less upkeep. The inside corners and the joint where wall meets floor or tub are not grouted but filled with a matching silicone or urethane sealant, because those joints move; buy a tube per shower.
The order list
- Wall tile, with 10% waste and two spare tiles.
- Floor mosaic sheets, with 10%.
- Edge trim or profiles, with 10%.
- Backer board, screws and mesh tape.
- Waterproofing membrane and corner pieces.
- Thinset, with buttering for large tile.
- Grout for walls and floor, and sealant for the corners.
Large tile on shower walls is now common; the large-format tile guide covers the clips and flatness it needs. The guide to tile size and grout joint covers the joint.