The renovation sequence, why tanking cannot be skipped, matching a shower to the water system you actually have, ventilation that works, and what can and cannot be moved cheaply.
The things worth deciding before the showroom
Most bathroom disappointments trace back to a decision made before anybody looked at the plumbing.
- What water system you have, because it decides which showers will work. A shower chosen for its looks and fitted to a system that cannot feed it is the most common bathroom regret there is.
- Where the soil pipe is, because that decides what a change of layout costs. Moving a basin is cheap; moving a WC can be a different job entirely.
- Whether the floor will take it, which matters for a bath, and matters a great deal for a wet room or a stone floor.
- How it will be ventilated, which is a regulatory requirement and also what stops the room going mouldy.
- Whether anything about the room needs to work for somebody in ten years’ time, which is easier to build in now than to retrofit.
Shower types and water pressure and bathroom layouts and soil pipes are the two to read first.
Start here, depending on what you are planning
| Your situation | Start with |
|---|---|
| Planning a full refit | A bathroom renovation, week by week |
| Choosing a shower | Shower types and water pressure |
| Wanting to move things around | Layouts and soil pipes |
| Considering a wet room | Wet room tanking explained |
| Planning for reduced mobility | Accessible bathroom design |
| Condensation, mould or a useless fan | Bathroom ventilation |
Tanking, and why it is the one thing never to economise on
A wet room has no tray and no lip. The entire floor and the lower walls are the shower, and the only thing preventing water reaching the structure is the waterproof membrane underneath the tiles.
Tiles and grout are not waterproof. Grout is porous, tile adhesive is porous, and water passing through them will find the floor. If there is no correctly installed membrane below, it reaches the joists, the ceiling below, and eventually somebody’s expensive discovery.
This is what makes it dangerous. Water tracks slowly, the damage accumulates out of sight, and by the time a ceiling stains below, the floor has been wet for a long time. It is not a defect you can correct without taking the room out again, which is why it is the one part of a bathroom never to take the cheapest option on.
Wet room tanking explained covers what a correct system looks like – the membrane, the corners and junctions, the upstands, the sealing at the waste, and the coverage area that is actually required.
See also wet rooms.
Ventilation and the things people regret
Bathroom ventilation covers extract rates, duct runs and why so many fans achieve almost nothing. The short version: a fan is only as good as its duct, and a powerful fan on a long flexible duct with several bends may be moving very little air.
Other things worth building in while the walls are open, because retrofitting them is disproportionate:
- Access to anything that will ever need attention – isolation valves, a concealed cistern, a pump, a shower valve cartridge. A removable panel now versus tiles off later.
- Isolation valves on every supply, so a tap change does not mean draining the house.
- Noggins where grab rails might one day go, even if none are being fitted – see accessible bathroom design.
- Underfloor heating, which cannot be added later without retiling – see bathroom underfloor heating.
- Adequate electrical provision for shaver points, lighting, mirror demisting and the extract, done to the requirements for a bathroom.
- A towel rail sized for the room, not just for towels – see towel rails.
A bathroom renovation week by week sets out the sequence, which matters because doing things in the wrong order is what turns a two-week job into a five-week one.
See also bathroom renovations, shower installation and cloakroom installation.
Planning a bathroom? The water system and the soil pipe decide more than the showroom does.
Questions we get asked about this
Can I have any shower I like?
No – the shower has to match the water system. A shower chosen on looks and fitted to a system that cannot feed it is the most common bathroom regret we see.
Is tanking really necessary in a wet room?
Yes. Tiles and grout are porous and water will pass through them. Without a correct membrane below, it reaches the structure – and the damage is invisible for years.
How much does it cost to move the toilet?
It depends entirely on the soil pipe – the distance, the available fall and the floor construction. A basin moves cheaply; a WC sometimes does not move at all without a pump.
Why is my bathroom always damp despite a fan?
Usually the duct rather than the fan. A powerful fan on a long flexible duct with several bends may be moving very little air.
Should I plan for accessibility now?
Noggins behind the plaster for future grab rails cost almost nothing while the walls are open and are disproportionate to add later. It is the cheapest futureproofing in the room.
How long does a bathroom take?
Longer than most people expect, and the sequence matters more than the hours. Doing things in the wrong order is what turns two weeks into five.
What we cover
Bathrooms
- A bathroom renovation, week by week
- Bathroom layouts, soil pipes, and what moves cheaply
- Bathroom ventilation: extractor sizing, ducting and condensation
- bathrooms guide 1
- bathrooms guide 2
- bathrooms guide 3
- bathrooms guide 4
- bathrooms guide 5
- bathrooms guide 6
- Designing an accessible bathroom that still looks like a bathroom
- Shower types and water pressure: matching the two
- Wet room tanking: the bit you never see and cannot skip
Need this doing?
Call and describe the problem — you will speak to an engineer, not a call centre. Written quotes, no estimates over the phone.