The Complete Wet Room Guide
A wet room is a beautiful thing when it is built right, and trouble when it is not. Here is what actually makes one work, from a specialist who installs them properly.
A wet room is a fully open, level-access shower space with no tray and no screen. The whole room is waterproofed so water can run freely to a drain set into the floor. Done well it looks effortless, lasts for decades and adds real value. Done badly it is one of the few tiling jobs where the failure is hidden until water is already where it should not be.
The difference is almost entirely in the parts you cannot see once the tiles are on. This guide walks through what those are, so you know what to expect and what to look for in any wet room quote.
What Makes a Wet Room Work
Four things that have to be right. Get them wrong and no amount of nice tiling saves the room.
Tanking (the waterproof membrane)
A wet room has no tray and no screen holding the water back, so the whole room has to be waterproof behind the tiles. Tanking is a continuous membrane applied to the floor and walls before tiling. Get it continuous and lapped correctly and the room stays dry for decades. Leave a gap at a corner or a pipe and water finds it. This is the stage that separates a wet room built properly from one that causes problems later.
The fall to the drain
The floor has to slope gently and evenly towards the drain so water runs away and never pools. That fall is formed before tiling, either with a pre-formed tray former or by grading the screed by hand. Too little fall and water sits. Too much and the floor feels wrong underfoot. It has to be judged correctly across the whole floor area.
Drainage that can cope
The drain and the pipework under it have to move water away as fast as the shower delivers it. Drain position, the type of waste, and how it ties into the existing plumbing all matter. A linear drain against a wall and a centre point drain give very different looks and both have to be set dead flush with the finished floor.
The right tiles, set out right
Floor tiles in a wet room need enough grip when wet, which usually means a textured or smaller-format tile so the grout lines add traction. Walls can be anything from large-format porcelain to natural stone. Whatever the tile, the setting out has to work around the fall in the floor and the drain without awkward cuts in the wrong places.
How I Install a Wet Room
The order the work happens in, and why each stage matters.
Site visit and plan
I look at the room, talk through what you want, check the floor build-up and where the drainage can run, and give you a clear written quote.
Strip out and prepare
Old fittings and tiles come out, the substrate is checked and made sound, and any boarding or repairs needed before waterproofing are done first.
Form the fall and fit the drain
The slope to the drain is formed and the drain is set to the correct finished floor level, ready to be tiled flush.
Tank the room
The waterproof membrane goes on across the floor and walls, with corners, junctions and pipe penetrations reinforced and sealed.
Tile and finish
Tiles are set out and fixed, then grouted and finished with clean, consistent silicone. The room is left tidy and ready to use once everything has cured.
Where Wet Rooms Go Wrong
The failures I get called out to fix on other people's work. All of them are avoidable.
- Tanking only the shower zone instead of the whole room, so splash and condensation get behind the tiles elsewhere.
- A floor fall that is uneven or too shallow, leaving standing water that never quite drains.
- A drain set proud or low of the finished floor, so it either traps water or looks wrong.
- Skipping reinforcement at corners and pipe penetrations, which is exactly where membranes fail.
- Glossy, low-grip floor tiles that become slippery the moment they are wet.
Every one of these comes back to rushing the waterproofing or the setting out. It is why I treat those stages as the job, and the tiling as the finish on top of them.
What does a wet room installation cost depend on?
A wet room is quote-based and sits at the higher end of bathroom work. These are the factors that decide where your price lands, and none of them is a place to cut corners.
The size of the room
A compact wet room and a large family bathroom converted to a wet room are very different amounts of work. Floor area and wall height both feed the tanking, the tiling and the setting-out.
The extent of the tanking
A true wet room tanks the whole floor and the wet walls, not just the shower zone. More waterproofed surface means more membrane, more reinforced junctions, and more time, all of which are real cost you want to see.
Forming the fall to the drain
The graded fall is formed before tiling, either with a pre-formed tray former or by hand-grading the screed. The method and the size of the floor decide how much time this stage takes.
Drainage and how it routes
A solid floor with an accessible waste run is straightforward. A suspended timber floor or an awkward route to the existing soil pipe is very doable, but it is more work, and a linear drain is a different job to a centre point.
The floor build-up underneath
What is already there matters. Timber floors move and need decoupling; old or uneven substrates need levelling and making good before any waterproofing goes on. Older South East London homes often need more of this.
The tiles and the setting-out
Grippy floor tiles, large-format walls, marble or mosaic all take different amounts of skilled time. The tiling also has to run true into the fall and around the drain, which is more demanding than a flat bathroom floor.
For attributed UK industry ranges and a fuller breakdown, see what a wet room installation costs and why a wet room costs more than a standard bathroom. For how these drivers apply to any tiling job, see what drives the cost of a tiling job. The only accurate number for your room is a written quote after a free site visit.
A Wet Room Done Properly
A recent project, start to finish.
Black Marble Wet Room
Black veined marble run from floor to the apex of a vaulted ceiling, with the entire room tanked to full height and graded to a flush linear drain. Read how it was planned and built.
Read the case study →Why Trust Your Wet Room to Me
- Specialist, not occasional. Wet rooms are a job I have installed for decades, not something I take on now and then.
- City & Guilds qualified, 44 years on the tools. The waterproofing and setting out are done to method, not by eye.
- No subcontractors. Your wet room is installed by me or my relative Paul, both qualified, both with the same standards.
- 5-year workmanship guarantee. Because a wet room is one job where you want the person who built it to stand behind it.
Wet Room Questions
A wet room is quote-based, and it sits at the higher end of bathroom work because it asks more of every layer under the tiles. The cost depends on the size of the room, the extent of tanking, forming the fall to the drain, the drain type and how it ties into your existing waste, the tile you choose, and the state of the floor build-up. Published UK ranges give a rough sense of scale (see what a wet room installation costs), but the accurate figure for your room comes from a free site visit. Ask for a free written wet room quote.
Because a wet room turns the whole floor and lower walls into a single waterproof, drained surface, which a standard bathroom does not. That means full tanking, a floor graded to a precise fall, drainage that can cope, and more demanding tiling and setting-out around that fall. Each of those is extra skilled time and materials on top of a normal bathroom, and none of it is optional. Here is exactly where the extra cost goes.
Not if it is built correctly. A wet room is fully tanked, which means the floor and walls are waterproofed behind the tiles before any tiling starts. Done properly it is arguably more watertight than a standard bathroom. Leaks come from corners cut on the waterproofing, which is why I never rush that stage and why every wet room I install is guaranteed for 5 years.
It depends on the space and how you want to use it. A wet room gives a completely open, level-access finish with no tray or screen, which suits smaller rooms, accessible bathrooms and a clean modern look. A walk-in shower with a tray is sometimes simpler to fit and easier to retrofit. I am happy to talk through both honestly on a site visit and tell you which makes more sense for your room.
Most can, but the floor build-up and the drainage are what decide how straightforward it is. A solid floor and an accessible waste run make for an easier job. A suspended timber floor or a tricky drainage route is still very doable, it just needs the right approach. I check all of this on the site visit before quoting so there are no surprises.
A wet room typically takes a little longer than a standard bathroom re-tile because of the extra waterproofing and the drying time the tanking needs. The exact timeline depends on the size of the room and the work involved, and I set it out clearly as part of the written quote.
For floors, a textured or smaller-format tile gives grip underfoot when wet. For walls, you have a free hand: large-format porcelain, marble and natural stone all look superb. The main thing is that whatever you choose is set out to work with the fall in the floor and the drain. I am happy to advise on tile choice as part of the quote.
Thinking About a Wet Room?
Tell me about your space and I'll arrange a free site visit, check the floor and drainage, and give you a clear written quote. Most enquiries answered the same working day.