Shower Tanking and Wet Room Waterproofing

What tanking is

Tanking is a waterproof membrane, liquid or sheet, applied to the walls and floor of the showering area before tiling. Tiles and grout slow water down but do not stop it, so the membrane is the real barrier that keeps water inside the shower and out of the structure of the house.

Every shower and wet area we build is tanked as standard. It is not an optional extra, because the cost of skipping it is a leak into the room below, which is a far bigger job than doing it properly the first time.

Where tanking goes and how far

In a shower enclosure, the walls are tanked to a sensible height around the showering zone and the floor or tray junction is sealed into the system. In a wet room or level access shower, the whole floor and the lower part of every wall are tanked, because the entire floor carries water to the drain.

Corners, joints and every pipe entry get reinforcing tape bedded into the membrane. These are the points where waterproofing fails, so they are the points that get the most attention. Our wet room installation page covers the full wet room build.

Tanking as a repair

Where an existing shower has leaked through the wall or floor, retiling alone does not fix it. The damaged area is stripped back, the structure checked and dried, and a proper membrane system applied before the new finish goes on.

If you are dealing with an active leak, our guide to leaking shower causes and fixes helps narrow down the source, and our ceiling and leak damage repairs page covers the making good below.

Systems and curing time

Different membrane systems suit different backgrounds and budgets, and each has a stated curing time before tiling can start. That drying time is built into the programme rather than rushed, because tiling over an uncured membrane traps moisture behind the tiles.

The written quote names the system being used, so when you compare quotes you can see whether tanking is included and to what extent.

Booking tanking work

Tanking is usually part of a wider shower, wet room or bathroom fitting job, and we also carry it out as a repair where waterproofing has failed. Quotes are free and in writing, and the work carries our 1-year workmanship warranty. Call 01268 206409 or send photographs through the quote form.

Timber floors, concrete floors and what changes

The floor under the shower changes how tanking is detailed. On timber floors the boards must be firm and overboarded where needed, because movement cracks both membranes and grout. On concrete, the surface is primed so the membrane bonds properly, and any falls towards a drain are formed before tanking.

Either way, the membrane is only as good as the surface beneath it. That preparation is invisible in the finished room, but it is the difference between waterproofing that lasts and waterproofing that fails at the first movement.