In short: A bathroom is renovated in this order: strip out, first-fix plumbing and electrics, floor preparation, boarding and plastering, tanking, floor tiling, wall tiling, second fix, silicone and snagging. Getting the sequence wrong is the most common cause of a job that has to be partly redone.
What's in this guide 5 sections
01 Why the order matters more than the fittings
Almost every avoidable bathroom problem is a sequencing problem. Tiling onto a substrate that was never levelled. Fitting the shower valve before the wall was tanked. Painting a ceiling before the plaster had dried. None of those are skill failures; they are order failures.
The sequence below is not a preference. Each stage produces the condition the next one needs, and skipping ahead means going backwards later.
02 The correct sequence, stage by stage
- Strip out. Suite, tiling and flooring removed back to the substrate, waste taken away, floors and access routes protected. You cannot survey what is behind the old bathroom until this is done.
- Assess what you have uncovered. Check the joists, the state of the pipework, the electrical circuits and whether the walls are sound. This is the moment to change the plan if something unexpected has appeared, not later.
- First-fix plumbing and electrics. New hot, cold and waste runs to their final positions, new circuits, extractor provision, underfloor heating cabling. Everything that will be buried happens now.
- Floor preparation. Levelling, backer board or ply overlay on timber floors, and forming falls if it is a wet room. Tiles bedded straight onto floorboards will crack — timber moves, tile does not.
- Boarding and plastering. Walls re-boarded or made good, ceilings skimmed. Plaster then needs 5 to 7 days to dry properly in a normal heated room.
- Tanking. Shower zones and wet room floors waterproofed with a liquid or sheet membrane taken into every corner and junction, and sealed around the drain. Tile and grout are water-resistant, not waterproof.
- Floor tiling, then wall tiling. Floor first, so wall tiles sit on a finished floor level and the junction is clean. Set out the whole room before fixing a single tile — decide where the cuts land before they land badly.
- Grouting and sealing. Natural stone is sealed before and after grouting. Movement and change-of-plane joints are siliconed rather than grouted rigid.
- Second fix. Suite, brassware, shower, screens, lighting and accessories fitted, then everything tested under load.
- Joinery and finishing. Boxing, panelling, vanity units, skirting and any bespoke elements.
- Silicone, clean, snagging walk-through. Then, and only then, decoration.
03 The three most common sequence mistakes
- Tiling before tanking. The tanking membrane goes under the tiles, not over them. Once the tiles are on, the only way to add it is to take them off.
- Decorating before the plaster has dried. Fresh plaster needs 5 to 7 days, and the first coat should be a watered-down mist coat rather than ordinary emulsion, or the paint will peel.
- Fitting the suite before tiling. Tiling around a fitted suite rather than behind it looks it, and it makes the suite very difficult to replace later.
04 Where decisions have to be made
Certain choices lock the sequence and cannot be changed once passed. Knowing when they arrive stops a job stalling while you decide.
| Decision | Must be made by | Why |
|---|---|---|
| Layout — is the toilet moving? | Before first fix | Drainage runs are set at first fix and cannot be changed afterwards without lifting the floor again. |
| Shower type — tray or wet room? | Before floor preparation | It determines whether the floor is lifted and falls formed. |
| Underfloor heating | Before floor preparation | It goes under the tiles, on insulation board. |
| Position of every socket, spur and light | Before first fix | Cabling is buried in the wall at first fix. |
| Tile choice and layout | Before tiling starts | Setting out depends on tile size; a late change means re-planning the whole room. |
| Brassware and shower valve | Before first fix | Concealed valves need pipework in specific positions. |
05 How the sequence changes for a wet room
A wet room follows the same order with two significant additions. The floor works are more substantial — lifting the floor, installing a former or forming falls in the screed, and fitting the drain — and the tanking stage covers the whole floor as well as the walls.
Both of those sit between first fix and tiling, and both have cure times that cannot be rushed. That is why a wet room typically runs 10 to 15 working days against 7 to 12 for a standard bathroom.