Why bathrooms are technically harder than they look
Bathrooms are the most failure-prone room in a London home, and bathroom renovations are the most failure-prone single-room project a contractor can take on. Wet rooms in particular have a long industry record of leaks, blown tiling, mould behind walls, joist rot — almost all from inadequate tanking or rushed construction. The technical demands are real: a fully tanked wet room needs primer plus liquid waterproofing membrane plus mesh tape at corners plus a fall-laid screed plus drainage detailing plus correctly sequenced tiling — eight steps in sequence with strict drying times and no scope to skip ahead. A standard family bathroom has fewer waterproofing demands but still requires correct shower-tray drainage, correct WC waste falls, proper extract ventilation, code-compliant electrical zoning, and joist support adequate for cast-iron freestanding baths (which can weigh 200kg empty, 400kg+ filled with bather). We approach every bathroom as a small technical project with full method statement, never as a 'just rip it out and replace it' job.
Wet rooms versus enclosed showers versus baths: planning the layout
Three broad shower configurations. Enclosed shower cubicle: traditional, separate cubicle with door, easy retrofit, tile-on-board substrate is fine, no tanking of surrounding floor needed. Walk-in shower with low-profile tray: contemporary, no door (just a glass screen), still uses a manufactured tray for drainage, easier to maintain than a full wet room. True wet room: no tray, floor falls to a drain, full tanking of floor and lower walls, contemporary high-end look but technically demanding and not always advisable on suspended timber floors. We typically recommend wet rooms only where the floor is solid concrete (modern apartments, ground floor on solid floor) or where the joists are exposed and we can install new fall-supportive substrate; on first-floor Victorian timber joists, walk-in showers with tray are usually a safer specification. Baths: still loved for families with young children and for resale value on family homes; freestanding rolltop, fitted apron-front, or built-in are all common in equal measure.
Tanking, screed and fall: the structural waterproofing that decides whether you leak in five years
Behind every well-finished bathroom is a correctly executed substrate. For a tanked wet room or shower: existing floor stripped back to joists or slab, plywood (18mm WBP minimum) screwed to joists at 150mm centres, primer applied, two coats of liquid membrane (Schluter Kerdi, Mapei Mapelastic, Bal Tank-It) with mesh tape at all corners and pipe penetrations, screed laid with correct fall to drain (1:80 typical, 1:100 minimum), full tanking again over screed before tiling. Walls: 12.5mm cement board (HardieBacker, Aquapanel) screwed at 150mm centres into studs, fully tanked to 2.0m height, mesh-taped at all joints and corners. This is where corner-cutting in the market costs homeowners £5,000–£20,000 in remedial work three years on. We follow manufacturer specification to the letter, photograph at each stage, and supply you with the photographic record at handover for warranty purposes.
Brassware: thermostatic mixers, rain heads, the spec choices that matter
Brassware is the visible spec of a bathroom and the most-touched daily. Choices: thermostatic versus manual mixer (always thermostatic now — scald safety, particularly with children), exposed versus concealed valve (concealed cleaner, exposed easier to service), single function versus diverter (rain head plus handset is the standard high-spec, requires diverter). Brands and price brackets: Hansgrohe Talis at £400–£800 (entry-spec premium), Hansgrohe Metris/Croma at £550–£1,200 (mid-spec), Vola from £1,200 to £3,500 (architectural-spec), Dornbracht at £1,500–£5,000 (premium-spec). Finish: chrome remains 60% of market, brushed brass and matte black taking growing share, gunmetal rising. We avoid budget brassware below £200/set as the failure rate at 3–5 years is high — internal cartridges fail, finishes peel, valve threads strip on service. The lifetime cost of a good brassware install is lower than the cheap alternative.
Tiling: large format, small format, what works where
Tile choice and tiler skill together determine 50% of finished bathroom impression. Large-format porcelain (60×120, 80×160, 120×280) creates a near-seamless contemporary look with minimal grout lines — popular for wet rooms, walk-in showers, full-wall splashback. Requires perfectly flat substrate (any deviation shows as cupping or hollow tiles) and a tiler practised in large-format handling. Medium format (30×60, 30×90) is the workhorse — easy to lay, forgiving of substrate, available in every aesthetic. Small format (20×20, mosaic) for character bathrooms, splashbacks, statement panels — labour-intensive, slow to lay, expensive in tiler time per m². Marble (real Carrara, Calacatta, Statuario) or marble-effect porcelain — the latter is now visually indistinguishable from real marble at 1/3 the cost and 1/10 the maintenance, our default recommendation. We hand-pick tilers with the right skill for each spec — large-format tiling is a specialism that not every tile mate can deliver.
Underfloor heating in the bathroom: electric or wet, and the warm-floor reality
Underfloor heating is now standard spec in any London bathroom renovation over £10,000. Two routes: electric mat heating laid in tile adhesive (works on any substrate, no plumbing involved, controlled by dedicated stat, £40–£80/m² installed including controls, typical 4m² bathroom £200–£400 hardware plus £400–£600 install), or wet UFH (plumbed warm water loop from the central heating system, more efficient running cost, more complex install, only viable on screeded floors or specific UFH boards on timber joists, £150–£280/m² installed). Electric is the default unless the bathroom is already on a screeded floor with wet UFH elsewhere. Both deliver the same daily comfort — a warm tile floor underfoot at 26–28°C is one of the genuinely transformative experiences of a renovated bathroom and rates highly on every post-handover survey we run.
The 2–4 week bathroom build: realistic timeline, realistic disruption
Bathroom renovations are short, intense projects. Week one: strip-out (existing suite removed, tiling chipped off, floor lifted if needed), first fix plumbing (new waste runs, hot/cold supplies repositioned for new layout, shower outlet relocated), first fix electrics (lighting circuits to new positions, shaver point, extract fan circuit, UFH stat circuit, zone-compliant socket if cloakroom), substrate prep (new floor, new wall lining where needed). Week two: tanking (multiple coats with drying time), screed and fall-laying if wet room, full waterproofing test before tiling. Week three: tiling (3–5 days for a typical bathroom), grouting, sealant. Week four: second fix (sanitaryware install, brassware, screens, accessories), commissioning of UFH and electrics, mastic sealants, final clean, handover. If the bathroom is the only bathroom in the house we work compressed shifts to deliver in 8–10 working days flat — possible but premium-rate. Most clients in larger homes accept full 3–4 week programme on a single bathroom and use an alternative WC and shower elsewhere in the property during works.
