Do I need a particular tile slip rating in a wet room?

Yes. Use a floor tile with an R10 or better slip rating, and R11 where the floor will regularly be wet, such as a family shower room. Polished porcelain and high-gloss finishes are not suitable for a wet room floor regardless of their rating, because the surface stays slippery when wet and shows every water mark.

How much more does a wet room cost than a walk-in shower?

In Greater London, expect a wet room to cost £1,500–£3,500 more than an equivalent walk-in shower in the same room, driven by tanking, a recessed or screeded former, a linear drain and the extra waterproofing labour. A walk-in shower with a low-kerb tray and a glass screen typically lands £2,000–£4,500 in materials and labour as a standalone upgrade.

Wet room vs walk-in shower in a small UK bathroom — which actually works?

Q: Is a wet room worth it in a small bathroom?

It depends on the floor structure. A wet room is worth it where the joists can take a recessed tray former or a screeded fall, because it gains you usable space and looks uncluttered. Where the floor cannot be lowered without cutting joists or moving services, a low-kerb walk-in tray gives you the same visual result with far less risk and cost.

Q: How much fall does a wet room floor need?

Aim for a fall of 1:60 to 1:80 across the showering area, which is roughly 7–10 mm over a 1500 mm floor. The fall must be continuous to a linear or centre drain, with no ponding points. Anything flatter will not clear and anything steeper feels unstable underfoot and makes large-format tiles hard to lay.

Last updated: 3 October 2026

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Most London bathrooms are between 4 and 7 m², and the shower is the element that decides how the room feels. The choice usually narrows to two options: a fully tanked wet room with the floor falling to a drain, or a walk-in shower with a low-kerb tray and a glass screen.

Both can look excellent. The difference is what has to happen under the floor, and whether your floor structure and ceiling height can accommodate it. Get that wrong and a wet room becomes a slow, expensive leak; get it right and it is the most elegant square metre in the house.

This guide compares the two on the four things that actually decide the outcome — tanking and fall, footprint, head clearance, and slip resistance — and shows where the money goes. For the wider room budget, start with our bathroom renovation cost guide.

The comparison in one table

Factor	Wet room	Walk-in with low-kerb tray
Floor build-up	Recessed former or screeded fall, tanked	Tray sits on the existing floor
Fall	7–10 mm across a 1500 mm floor	Built into the tray
Typical footprint	Any — but 1200 × 900 mm minimum to be usable	1500 × 900 mm standard
Extra cost vs standard shower	£1,500–£3,500	£2,000–£4,500 as a standalone upgrade
Risk profile	High if tanking or fall is compromised	Low

Tanking and the fall: what a wet room actually needs

A wet room is not a bathroom without a tray. It is a bathroom where the entire floor and the lower walls of the showering zone are waterproofed as a continuous, sealed system, and the floor is shaped so water reaches the drain without pooling.

The fall should be between 1:60 and 1:80 — roughly 7–10 mm over a 1500 mm floor. That is a precise number, not a suggestion. Flatter than that, water sits in shallow pools that never quite clear and the grout starts to discolour. Steeper than that, the floor feels unstable underfoot and large-format tiles become difficult to lay without lipping.

The tanking itself must be a proper liquid-applied or sheet membrane, carried up the walls at least 150 mm and to full height inside the showering zone, with reinforcing tape at every corner and pipe penetration. This is the part that cannot be inspected once the tiles are on, which is why the specification and the installer's competence matter more than the tile choice.

On a timber floor, the safest route is a recessed tray former set between the joists, which creates the fall and the drain connection in one component. On a concrete or screeded floor, the fall can be formed in the screed. Where neither is possible without cutting joists or moving a soil run, a wet room is the wrong answer for that room, and no amount of design intent will change it.

Walk-in trays and the 1500 × 900 footprint

A low-kerb walk-in tray is typically 1500 × 900 mm, with a 25–40 mm upstand that is low enough to step over comfortably but high enough to contain water. That footprint is remarkably close to what a usable wet room needs anyway, which is the core of the argument.

The tray version moves the waterproofing problem into a factory-made component. The waste is built in, the fall is moulded in, and the interface with the floor is a bead of sealant and a tiled upstand rather than a site-formed screed. For most London refurbishments, that removes the single largest source of callbacks.

Where the tray wins decisively is speed and certainty. It can be installed and tiled in a day, it does not require the floor to be lowered, and it does not depend on the joist direction being convenient. The visual difference between a well-detailed low-kerb tray and a wet room is small once a fixed glass screen is added — and the screen is worth having in both cases to stop spray reaching the rest of the room.

Sloped ceilings and head clearance

In loft and under-eaves bathrooms, the ceiling decides the layout. Allow a minimum of 1800 mm from the finished floor to the underside of the shower head, and around 2000 mm to any ceiling or sloping soffit above the standing position. Anything tighter and the shower is uncomfortable for anyone of average height.

This is why the shower position must be set on a section drawing, not chosen on the floor plan. In a room under a pitched roof, the usable standing zone may only be 900 mm wide, and it is usually against the party wall where the ceiling is highest. If that is also where the soil stack runs, the layout has to resolve both constraints at once.

For a loft bathroom, the structural work is often happening at the same time. Our loft conversion cost guide covers the shell and floor structure that the bathroom sits within.

Anti-slip tiles are not optional

In either specification, the floor tile must carry an R10 slip rating as a minimum, and R11 where the floor will regularly be wet — a family shower room, for example. A polished porcelain floor with an R9 rating is a slip hazard the moment soap is involved, regardless of how good it looks in the showroom.

Where the room also serves someone with reduced mobility, or where you expect the property to be lived in long-term by an older household, it is worth designing to the intent of the accessibility guidance from the outset: a level or low-threshold entry, a 1500 mm clear turning space, and a wall-mounted seat position planned into the structure rather than added later.

Anti-slip and large-format are not mutually exclusive. A 600 × 600 mm matt-grip porcelain with a fine-textured surface gives you fewer grout lines and a safe floor. What you cannot have is a mirror-polished surface on the shower floor.

Lighting the wet room at night

A wet room at night is a lighting problem before it is a plumbing one. A single ceiling light in a wet zone flattens the space and casts shadows exactly where you stand. A combined flush shower head and downlight is a neat solution, but it must be rated IP65 and installed with the correct gland and sealed cable entry — not simply a standard downlight pushed into a wet void.

A hidden LED strip above a niche shelf, tightly diffused and again IP65, gives a soft wash that makes the room read far more generously than its floor area. Keep it warm at 2700 K. Cool white light makes stone and tile look grey and clinical, and it is the most common lighting error in London wet rooms.

For the full zonal logic — including where a fitting is genuinely not permitted — the key point is that every fitting in the showering zone must be rated for the zone it sits in, sealed at the cable entry, and protected by a 30 mA residual current device. We set this out on the electrical layout before first fix, because changing a lighting position after tanking means breaking the waterproofing.

Which one should you choose?

Choose a wet room where the floor can genuinely be lowered or screeded to a 1:60–1:80 fall, where the joists run the right way for a linear drain, and where you value the seamless floor enough to pay the premium.
Choose a walk-in tray where the floor structure is constrained, where the room is above a habitable space you cannot risk, or where you want the same visual result with less cost and less uncertainty.
In both cases fit a fixed glass screen, an R10+ floor tile, IP65 lighting in the wet zone, and a 2700 K warm layer that makes the room usable in the evening.

We set the shower type, the fall and the lighting out together before demolition, and price the tanking and drainage as visible line items rather than an allowance. Our bathroom service covers the full build-up from strip-out to final seal, and we work across Camden, Islington and the rest of Greater London.

Frequently asked questions

Is a wet room worth it in a small bathroom?

It depends on the floor structure. A wet room earns its premium where the floor can be recessed or screeded, because it gains usable space and looks uncluttered. Where the floor cannot be lowered, a low-kerb walk-in tray gives the same visual result with far less risk.

How much fall does a wet room floor need?

Aim for 1:60 to 1:80 — roughly 7–10 mm over a 1500 mm floor — continuous to the drain with no ponding points. Flatter will not clear; steeper feels unstable and makes large tiles hard to lay.

What head clearance do I need above a shower?

A minimum of 1800 mm from finished floor to the underside of the shower head, and about 2000 mm to any ceiling or sloping soffit above the standing position. In a loft bathroom this usually decides the shower location.

Do I need a particular tile slip rating?

Yes — R10 or better on the floor, R11 where the floor is regularly wet. Polished porcelain is unsuitable for a shower floor however good it looks, because it is slippery when wet and shows every mark.

How much more does a wet room cost?

Expect £1,500–£3,500 more than an equivalent walk-in shower in Greater London, driven by tanking, the former or screed, the linear drain and the extra waterproofing labour.

See both options in your actual room

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