Shower Tile Calculator — Enclosure Tiles, Grout & Membrane
Calculate tiles, grout, C2 S2 adhesive and liquid membrane for a shower enclosure. Covers three-wall and walk-in shower layouts with accurate waste factors for the cuts required around niches, drains and showerheads.
How the shower tile calculator works
- 1Measure three shower walls (or two for walk-in) — height × width per wall
- 2Add shower floor area; subtract drain area
- 3Apply 15–17% waste for wall tiles (high cut frequency around fixtures)
- 4C2 S2 deformable adhesive required: area × 5.5 kg/m² (large format) or 4.5 kg/m² (≤400 mm)
- 5Liquid membrane: minimum 2 coats on floor + 300 mm up all walls + shower corner joints
- 6CG2 W water-resistant grout: calculated from tile and joint geometry
Worked example
Walk-in shower: back wall 1.2 m × 2.1 m, side wall 0.9 m × 2.1 m, floor 1.2 m × 0.9 m. 300×600 mm tiles.
Wall area: 4.41 m² + 15% waste = 5.1 m². Floor: 1.08 m² + 15% = 1.24 m². Adhesive: ~32 kg. Membrane: ~2 L liquid waterproofing.
Frequently asked questions
What type of adhesive is required for shower tiles?
C2 S2 highly deformable adhesive is required for all shower enclosures — it accommodates thermal movement and prevents tiles from debonding. C2 S1 is the minimum for standard bathroom walls. Never use C1 in shower areas.
What grout should I use in a shower?
Use CG2 W (water-resistant, reduced water absorption) or epoxy grout (RG class). Standard CG1 cement grout absorbs water and harbours mould. Epoxy grout is the most durable choice for daily shower use.
How do I waterproof a shower before tiling?
Apply a liquid tanking membrane or sheet membrane to the floor and 300 mm up all walls. Pay extra attention to corners — use membrane tape embedded in the first coat. Allow each coat to dry fully before tiling.
What tile size works best for a shower floor?
Small mosaic tiles (50×50 mm or 100×100 mm) conform to the fall-to-drain slope more easily than large format tiles. Large tiles need precision cutting around the drain and precise substrate levelling.
Do I need to seal grout in a shower?
Cement grout joints in showers should be sealed annually with a penetrating grout sealer. Epoxy grout does not require sealing. Silicone joints at corners and changes of plane must never be grouted — replace silicone every 5–7 years.