A bathroom installation is the full process of removing an old bathroom and fitting a new one — covering plumbing, waste connections, tiling, electrics and the sanitaryware itself (the bath, basin, WC and shower). A typical refit by a small team takes one to two weeks, with the work moving through a fixed sequence of trades rather than happening all at once.
What a bathroom fit involves
At its simplest, a fit means stripping out the existing room back to the bare walls and floor, making good any surfaces underneath, then installing new fittings and finishes. The "sanitaryware" — a trade term for the ceramic and acrylic items you use, such as the toilet, basin and bath — is only one part of it.
Behind those visible items sits a layer of unseen work: hot and cold supply pipes, waste pipes, electrical cables for lighting and shaver sockets, and sometimes structural changes if a wall is moved or a shower tray needs a recessed floor. The quality of that hidden work is what determines whether the room performs well for years or causes leaks and damp.
Most jobs draw on several trades — a plumber, a tiler, an electrician and sometimes a plasterer or carpenter. On a small project one person may cover more than one role, but the same tasks still need doing in the right order.
The order the work happens in
A typical refit by a small team takes one to two weeks, with the work moving through a fixed sequence of trades rather than happening all at once.
Sequence matters because each stage depends on the one before it. Tiling onto an unprepared wall, or fixing a basin before pipework is tested, leads to expensive rework. A common running order looks like this:
- Strip-out: old fittings, tiles and sometimes flooring are removed and waste taken away.
- First fix: pipework and electrical cables are run to where new fittings will sit, while walls are open and accessible. This is the stage to confirm the exact position of every item.
- Walls and floor preparation: any damaged plaster is repaired, and surfaces are made flat and sound. Tile backer board or a waterproof membrane (called "tanking") is fitted in shower areas.
- Tiling: wall and floor tiles are laid and grouted once surfaces are ready.
- Second fix: the visible fittings go on — taps, the WC, basin, shower valve, towel rail and light fittings are connected to the pipes and cables left at first fix.
- Sealing and testing: joints are sealed with silicone, the system is filled and checked for leaks, and the room is cleaned ready for use.
The gap between first and second fix is when tiling and plastering happen, so the two plumbing visits are usually days apart. Planning around this helps explain why a fit rarely finishes in a single uninterrupted run.
Showers, baths and sanitaryware choices
Shower installation is often the part with the most variables. The three common types are electric showers, which heat water on demand from the cold supply; mixer showers, which blend stored hot and cold water; and pumped or "power" showers, which boost flow. The right choice depends on the existing system — a combi boiler, for example, suits mixers but not a pump fed from stored water.
Water pressure is the deciding factor for many households. A low-pressure gravity system fed from a tank may give a weak flow through a standard mixer, so a pump or a different shower type may be needed. It is worth checking pressure and flow before choosing fittings rather than after.
For baths, acrylic is light and warm to the touch, while steel and stone-resin options are heavier and need a solid floor and good support. Sanitaryware comes in two broad mounting styles: floor-standing units, and wall-hung items fixed to a concealed metal frame, which give a cleaner look but require a sturdy wall build behind them. Close-coupled toilets keep the cistern visible; concealed cisterns sit inside the wall and need an access panel for maintenance.
Hidden work: waste, supply and ventilation
Waste and supply connections are the most important part to get right. The "supply" is the incoming hot and cold water; the "waste" is the pipework carrying used water and soil away. Each fitting needs the correct pipe diameter and a fall — a slight downward slope — so water drains properly. A WC needs a larger soil pipe than a basin, and moving it far from the existing stack can be difficult.
Traps under each fitting hold a small amount of water to block drain smells; they must be the right size and kept accessible. Where a new basin or shower is added in a position with no existing waste, a pump may be required to lift waste to the drain.
Ventilation is easy to overlook. Bathrooms generate a lot of moisture, and an extractor fan sized for the room reduces condensation and mould. Building regulations set requirements for fan performance and for electrical work in the zones near water, so an electrician should certify that side of the job.
What moves the final price
Two bathrooms of the same size can differ widely in cost. The biggest drivers are usually the amount of pipework that has to be moved and the standard of the fittings chosen, rather than the room's dimensions alone.
- Layout changes: keeping fittings where they are is cheaper than relocating the WC or moving the bath to a new wall.
- Fittings quality: sanitaryware, taps and shower valves span a very wide range; a frameless screen or wall-hung suite costs more to buy and to fit.
- Tiling: the area covered, tile size, pattern and the substrate preparation all affect labour time.
- Hidden problems: rotten subfloors, old pipework needing replacement or damp found after strip-out add cost that may not be visible at the quoting stage.
- Access and disposal: upper-floor rooms and waste removal add time and expense.
When comparing quotes, it helps to check exactly what each one includes — whether tiling, making good, electrical certification and waste removal are all covered, or priced separately. A detailed written quote based on a site visit tends to be more reliable than an estimate given over the phone.