UK trade pricing guides put tanking at about £25–£50 per m², or £150–£400 for a shower area (trade2base, June 2026).
For a full wet room, MyBuilder lists £300–£1,200 for installing the waterproofing, and £500–£1,200 for the tanking kit and membranes (August 2026). Always price tanking as its own line on the quote.
Tile and grout are not waterproof. Water gets through grout joints over time, so every shower, wet room and bath surround needs a waterproof layer behind the tiles. Tanking is quick to skip and very expensive to put right later, so it deserves its own line on the quote.
Published tanking prices
| Item | Typical UK price | Source |
|---|---|---|
| Tanking / waterproofing, per m² | £25–£50 | trade2base, June 2026 |
| Tanking a shower area | £150–£400 | trade2base, June 2026 |
| Wet room waterproofing installation (labour) | £300–£1,200 | MyBuilder, August 2026 |
| Wet room tanking kit and membranes (materials) | £500–£1,200 | MyBuilder, August 2026 |
For context, a complete wet room costs around £5,000–£13,000 on average (Checkatrade, June 2026), and takes 4–7 days. Waterproofing is a small part of that cost, but it's the part that causes the most damage if it fails.
What a tanking price should cover
- Priming the substrate, if the system needs it.
- Tape and corner pieces at every internal and external corner, and at the joint between wall and floor.
- Collars around pipes and the valve, and sealing around the drain or tray.
- The coats the manufacturer specifies. Liquid systems usually need at least two.
- Drying time before tiling. This is often what pushes a shower into a second day.
How much to tank: trade2base's wet room guide suggests tanking the whole floor of a wet room and at least 300 mm up every wall, more near the shower head. In a shower enclosure, tank the full tiled area inside the enclosure.
Per m² or per area?
Per m² works for large areas like wet room floors and full walls. For a single shower, a fixed price per area is simpler for the customer and protects you on small jobs. Most of the time goes on corners and pipe collars, not the flat area. The £150–£400 shower-area range above reflects that.
Sources
- trade2base: Wall tiling costs UK · June 2026; tanking per m²
- trade2base: Shower installation costs UK · June 2026; tanking a shower area
- trade2base: Wet room costs UK · June 2026; wet room tanking coverage
- MyBuilder: Cost of a wet room · updated 21 August 2026; waterproofing materials and installation
- Checkatrade: Wet room installation costs · June 2026; whole wet room costs and timescales
Prices change. Figures were checked on 20 October 2026; always check current costs and your own figures before quoting.