Wet Room Tanking Beneath Seamless Finishes
Tanking is the waterproof layer that keeps water inside a shower or wet room and away from the walls, floor and structure behind it. The decorative surface you see is not the part doing that job. We plan the tanking with the finish, so the substrate, falls, drain, corners and joints work together before microcement or another surface goes on top.
Where this works
- Level-access showers and open wet rooms
- Shower enclosures being converted to a seamless finish
- Bathroom floors and walls within splash zones
- Microcement wet room refurbishments on sound backgrounds
How we install it
- 1Check the room before the membrane
Tanking can only perform on a background that is stable and suitable for the chosen system. We look at the walls, boards and floor, and how the room has been built. Movement in timber floors, weak plaster or loose tiles must be resolved first. The position of the drain and the falls towards it are agreed before any waterproofing starts, because water should leave the floor rather than sit on it.
- 2Detail the weak points first
Leaks usually start at corners, pipe entries, the drain and the junction between floor and wall, not in the middle of a flat surface. These points are reinforced with the tapes, collars and fittings that belong to the selected system. Joints between different materials need attention as well. Getting these details right matters more than the colour of the finished room.
- 3Apply and cure the tanking system
The membrane is applied in the coats and coverage the manufacturer specifies, extending across the wet zone and up the walls as the design requires. Curing conditions are checked between stages. The layer must be continuous: a gap at a fixing or an edge defeats the purpose. The finish is applied only once the tanking is ready to receive it.
- 4Finish, seal and hand over
With a microcement wet room, the decorative layers and sealer go over the tanking to create a seamless surface. With tiles, the adhesive and grout must suit the membrane. At handover we explain how long the room should be left before use and which cleaning products suit the finish. Silicone or flexible joints at changes of plane are maintenance items and are checked over time.
Shower tanking and microcement wet rooms
A microcement wet room gives a continuous floor and wall surface without grout lines, but the microcement and sealer are a finish rather than the waterproofing itself. Shower tanking beneath it provides the barrier. Planning both together avoids incompatible layers and makes the drain and threshold details neater. Our microcement bathrooms page covers the finish, colours and everyday care.
What affects the cost of tanking?
Price depends on the size of the wet zone, the state of the existing walls and floor, whether tiles are removed, the drain arrangement and how many pipes and corners need detailing. A level-access floor with new falls is a bigger job than tanking a shower enclosure. A clear quote separates preparation, the tanking system and the finish so you can see what is included.
Choosing who does the work
Ask which tanking system is proposed, how the drain and corners are detailed and whether the finish is compatible with it. One contractor responsible for both layers removes doubt over who is accountable where they meet. If a plumber is relocating the drain or supplies, agree the sequence before the waterproofing so pipework is not disturbed after it is installed.
Common pitfalls we prevent
Frequently asked
What is tanking in a wet room?+
Tanking is a waterproof layer applied to the walls and floor of the wet zone, beneath the visible finish. It keeps water away from the structure behind, while the finish provides the look and the cleanable surface.
Can you use microcement in a wet room?+
Yes, when it is applied over a suitable tanking system on a stable background, with correct falls to the drain and a compatible sealer.
How long does wet room tanking take?+
It depends on preparation, the number of details and the curing time of the system between coats. The finish follows once the tanking is ready, so allow for both stages in the programme.
Can tanking go over existing tiles?+
Only where the tiles are firmly bonded and the system is suitable for that background. Hollow or loose tiles must be removed first, and the drain and falls still need checking.
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