Wet Room Installation Guide | Cotswold Maintenance Group

Wet Room Installation Guide: What It Is, Who It Suits and What's Involved

A wet room is one of those terms that gets used loosely, sometimes for a proper tanked, floor-drained shower space, sometimes for little more than a shower tray with the curb removed. This guide sets out what a genuine wet room installation involves from start to finish, who it actually suits, and the decisions you'll need to make before anyone lifts a floorboard.

Key takeaways

A genuine wet room has no shower tray, the tanked floor itself falls to a drain.

Suits period cottages, family bathrooms and mobility-focused designs alike, but plan a bath elsewhere in the house if you rely on one.

Drain type, screen and tile size need deciding before the floor is opened up.

Expect roughly £5,500 to £13,000+ depending on drain type, floor structure and finish.

What a proper wet room actually is

A true wet room is a fully tanked, waterproofed room with the floor falling to a drain, so the whole space can get wet without water finding its way anywhere it shouldn't. There's no shower tray and usually no visible step, just a level or gently sloped floor that carries water to a linear or point drain.

This is different from a shower enclosure with a low-profile tray, which is sometimes marketed as a wet room but doesn't need the same structural work. A genuine wet room needs the floor built up or dropped to create fall, a waterproofing membrane taken up the walls, and a drain sized for the space. It's a bigger job than a standard refit, but done properly it's also one of the most durable and easiest to clean bathroom formats there is.

Who a wet room suits

Wet rooms work brilliantly in en-suites and family bathrooms where you want a clean, open, easy-to-maintain shower space, and they're increasingly popular in period Cotswold stone cottages where an awkward, narrow bathroom doesn't easily take a bath and separate shower cubicle. A wet room can make a small or oddly shaped room feel far more usable because there's no enclosure boxing it in.

They also suit households planning ahead for mobility, since a level-access wet room removes the trip hazard of a bath or shower step. That said, if you're the only bathroom in the house and rely on a bath for children or for soaking, it's worth thinking carefully before removing it entirely, a wet room and bath can coexist in a larger room but it needs planning at design stage.

The core components of the build

Every proper wet room installation has the same core elements regardless of size: floor preparation to create fall towards the drain, a waterproofing (tanking) system taken across the floor and up the walls to at least 1800mm around the shower area, a correctly sized and positioned drain, tiling with appropriately sized joints, and a screen or partial wall if you want to keep splash contained.

Behind the scenes there's also first-fix and second-fix plumbing for the shower valve and any additional outlets, and electrics for lighting, extraction and underfloor heating if specified. Because plumbing, electrics and tiling are all interdependent in a wet room, having them handled by one team avoids the finger-pointing that happens when a leak shows up months later and three different trades were involved.

Design decisions to make early

Before work starts, decide on drain type and position (linear drains along a wall are popular and visually neat, point drains in the centre of the room are simpler on some floor structures), screen or no screen, tile size, and whether you want underfloor heating. These choices affect the falls, the tanking detail and the floor build-up, so they need settling before the floor is opened up, not halfway through.

It's also worth deciding early whether you want a completely level threshold from the rest of the house, which usually needs a floor drop or deck former, particularly relevant on suspended timber floors common in Victorian and Edwardian Gloucester and Cheltenham terraces.

What a site visit and quote should cover

A proper quote follows a home visit, not a phone estimate, because floor type, joist direction, ceiling height below and existing drainage all affect the price and the method. During a free design and quote visit we'd expect to check the floor structure, locate existing soil and waste runs, discuss drain type and tile choice, and give you a written specification, not just a headline figure.

A written guarantee should cover the workmanship on the waterproofing and installation, since that's the part that causes problems if it's rushed. If a quote doesn't mention tanking by name, ask what waterproofing system is being used and get it in writing.

Typical costs and timescales

Wet room conversions typically run from around £5,500 for a straightforward en-suite on a solid floor with a point drain, up to £9,000-£13,000 or more for a full bathroom with a linear drain, underfloor heating and large-format tiling, or where the floor structure needs significant work. These are broad ranges and every property differs.

Most wet rooms take between one and two weeks depending on floor type, drying and curing times for the tanking, and whether structural floor work is needed. See our dedicated guide on wet room timescales for a day-by-day breakdown.

Quick questions

Is a wet room the same as a walk-in shower?

Not quite. A walk-in shower usually still has a shower tray, even a very low-profile one, sitting on top of the floor. A true wet room has no tray at all, the floor itself is tanked and falls to a drain, so the finished floor is continuous throughout the room.

Can I have a bath and a wet room area in the same bathroom?

Yes, in a larger room it's common to have a bath at one end and a fully tanked, drained wet area at the other, with a screen or glass panel to reduce splash onto the bath surround. This needs to be planned at the design stage so the falls and tanking are positioned correctly.

Does a wet room smell or feel damp over time?

Not if it's installed correctly. A properly tanked wet room with adequate ventilation and correctly falling floors doesn't hold standing water, which is what causes damp and odour problems. Poor extraction or a badly fitted drain are the usual causes when this does happen.

Will a wet room affect my home's resale value?

A well-fitted wet room is generally seen as a desirable feature, particularly in en-suites, though opinion varies if it's the only bathroom in a family home with no bath at all. It's worth thinking about your household's needs and the local market rather than following trend alone.

Do I need planning permission for a wet room?

Almost never, as this is normally treated as internal alteration rather than development. If you're in a listed Cotswold stone property, it's worth checking with your local conservation officer before altering original floor structures, but this is about listed building consent, not planning permission as such.