Wet Room Installation London: Cost, Design and What to Expect
Wet rooms are increasingly popular in London flats and bathrooms where space is at a premium. This guide covers tanking, drainage options, tiling, ventilation, and the full cost range for a wet room installation in London.
What Is a Wet Room?
A wet room is a fully waterproofed shower room where the shower area is open to the rest of the space — no shower tray, no enclosure. The floor is graded toward a drain, and the entire room (or the shower zone) is tanked to prevent water penetrating the structure. In practice, this means a tiled, level-access shower integrated into the bathroom floor.
Compared to a standard shower enclosure, a wet room removes the physical threshold and frame, making it accessible and easier to clean. In London flats and houses with small bathrooms, removing a shower tray and enclosure can make the room feel significantly larger.
Why Wet Rooms Are Popular in London Properties
London's housing stock skews toward period conversions — Victorian and Edwardian terraces with small bathrooms, and 1960s–1980s conversions with awkward bathroom layouts. Wet rooms suit these spaces well because:
- No shower tray means no step — better for older occupants and building regulations accessibility requirements
- The visual openness makes small bathrooms appear larger
- Modern London renovations and refurbishments frequently specify wet rooms for resale appeal
- Easier to clean — no shower tray crevices or enclosure frames to maintain
Tanking — the Waterproofing Requirement
Tanking is the critical element of a wet room installation. Without proper tanking, water will work through grout lines and tile adhesive over time and cause structural damage, damp, and mould — especially in London's older properties with timber floors and Victorian joists.
Tanking systems include:
- Liquid waterproofing membranes (BAL Waterproofing System, Mapei Mapelastic): applied to walls and floor before tiling. Most common for wet rooms.
- Sheet membrane systems: bonded to substrate before tiling. More robust but more expensive.
- Wet room boards (Wedi, Schlüter Kerdi-Board): rigid foam boards with integral waterproofing. Pre-formed shower gradients are available. Popular where existing floors are timber and not suitable for wet screed.
The tanking must cover the entire shower zone floor and walls to at least 1.8m height. If the whole room is used as a wet room, the entire floor and lower walls must be tanked.
Drain Options
Two main drain types are used in wet room installations:
- Centre drain: floor graded from all four sides toward a central point. Standard option and often the most practical for square shower zones.
- Linear drain: a channel drain along one wall, allowing the floor to grade in a single direction. Suits larger wet rooms, walk-in shower designs, and allows large-format tiles (fewer cuts, cleaner look). More expensive — linear drains cost £80–£250 vs £30–£80 for a centre drain.
The fall on the floor must be adequate (typically 1:80 minimum gradient) to drain water without pooling. This is achieved with wet room boards or a sand-and-cement screed — the installer sets the gradient before tiling.
Tiling and Slip Resistance
Wet room floors must use tiles rated R10 or above for slip resistance (R10 is suitable for domestic wet rooms). Large-format tiles (600×600mm or larger) are visually popular but require more cuts around the drain and on the gradient — which adds labour cost.
Smaller mosaic tiles (50×50mm, 100×100mm) accommodate the gradient more easily and provide more grout lines which improve grip. However, more grout lines mean more maintenance.
Ventilation — a Building Regulations Requirement
Building Regulations Approved Document F requires mechanical extraction in bathrooms with no opening window. For wet rooms, an extract fan rated at minimum 15 litres/second is required. In London properties — where many bathrooms are internal (no external wall) — this is non-negotiable.
Continuous running fans with humidity sensors (Vent-Axia, Manrose) are preferred over pull-cord triggered fans — they run when moisture is present rather than only while the occupant is in the room, preventing condensation buildup on cold walls.
Wet Room Installation Costs in London 2025
- Basic wet room (small shower zone, centre drain, ceramic tiles): £2,500–£3,500
- Mid-range (full room tanked, linear drain, porcelain tiles): £3,500–£5,000
- High-specification (designer tiles, bespoke fittings, floor heating): £5,000–£6,000+
Timeline is typically 7–12 working days: day 1–2 strip out and prepare substrate; day 3–4 tanking; day 5–8 tiling; day 9–10 grouting, fixtures, and commissioning.
Planning Permission
A wet room installation is an internal alteration — planning permission is not required. If the property is listed, listed building consent may be required before altering the bathroom fabric. For flats, check the lease for any requirement to notify the freeholder of bathroom alterations.
Frequently asked questions
How much does a wet room cost in London?
A wet room installation in London typically costs £2,500–£6,000 depending on size, drain type, tiles chosen, and whether the existing floor and walls need significant preparation. A basic conversion of a small shower zone with centre drain and ceramic tiles sits at the lower end; a full-room wet room with linear drain and large-format porcelain tiles sits at the upper end.
Can you DIY a wet room installation?
Tiling and basic plumbing work is DIY-capable for competent homeowners, but the tanking — the waterproofing membrane application — must be done correctly or water damage results. In London properties with timber floor joists, incorrect tanking causes serious structural damage over time. Most installers recommend using a professional for at least the tanking and drain installation, even if the tiling is done separately.
Do you need planning permission for a wet room in London?
No — wet rooms are an internal alteration and do not require planning permission. Building Regulations approval is not required for like-for-like bathroom refurbishments, though if you are moving a drain or adding electrical circuits, those works are notifiable. If your property is listed, check with your local conservation officer before altering any historic fabric.
What tiles are best for a wet room floor?
Tiles used for wet room floors must achieve R10 slip resistance rating as a minimum. Smaller format tiles (mosaic or 200×200mm) accommodate the gradient naturally and provide good grip from the higher density of grout lines. Large-format porcelain tiles look excellent but require precise gradient setting and careful cutting around the drain. Avoid polished marble or polished porcelain on wet room floors — they are slippery when wet regardless of format.