Bathroom & WC Plumbing
Safe Water Connections and Odour-Free Drainage.
Water supply and waste connections for washbasins, showers, baths, WCs, concealed cisterns, bidet sprays, washing machines and bathroom mixer taps must be prepared professionally.
Request a Quote for Your Project →Bathroom and WC plumbing is critical infrastructure that prevents leaks, odours and drainage problems.
Bathroom plumbing requires the cold water, hot water, soil and waste pipes, floor gully, shower drain, concealed cistern and appliance connections to be planned correctly together.
The most important aspect of bathroom and WC plumbing is that every point of water use is prepared at the correct height, with the correct diameter, fall and materials. Faults end up hidden under tiles, which makes later repairs difficult and costly.
As the shower drain, washbasin waste, WC outlet, washing machine waste and floor gully all work within the same system, odour prevention, venting, falls and tightness must be assessed together.
Which connections must be planned correctly in bathroom plumbing?
Washbasin, shower, WC, concealed cistern, washing machine and bathroom drainage systems are described below, with technical dimensions, pipe types and installation details.
Washbasin and Mixer Tap Water Connections
Washbasin plumbing consists of hot and cold water outlets and the basin waste. The mixer tap may be wall-mounted, deck-mounted or mounted on a vanity unit, so the connection heights must be determined in advance according to the chosen furniture and fittings.
It is important that the isolating valves under the basin are accessible. Tidy, leak-tight connections make it easier to replace the mixer tap, service the trap or fit the vanity unit.
Technical installation details
| Pipes used | PPR, PEX, PE-RT, multilayer composite, copper |
|---|---|
| Water supply connection | Usually 1/2” hot and cold water outlets |
| Waste pipe diameter | Usually Ø40 / Ø50 mm for the washbasin |
| Points to note | Mixer tap type, furniture dimensions, trap access, hot/cold orientation and leak testing |
Shower, Bath and Linear Drain Plumbing
For a shower, both the water supply connections and the waste pipe must be prepared correctly. Shower mixers, thermostatic mixers, concealed mixers, shower sets, bath mixers and linear shower drains each require different dimensions and installation details.
The most critical point in the shower area is that water reaches the drain at the correct fall without standing on the floor. An incorrect fall, insufficient drain capacity or faulty waterproofing can cause leaks, odours and water penetrating to the floor below.
Technical installation details
| Area of application | Shower enclosures, walk-in showers, baths, linear drains, floor gullies |
|---|---|
| Water supply connection | 1/2” hot and cold water outlets; for concealed systems, according to the manufacturer’s dimensions |
| Waste pipe diameter | Usually Ø50 mm; Ø75 mm can be considered for high flow rates |
| Points to note | Fall, waterproofing, drain capacity, trap height, maintenance access |
WC and Concealed Cistern Plumbing
WC plumbing requires the waste outlet, water supply, concealed cistern installation and support frame to be positioned correctly. For wall-hung WCs, secure installation of the support frame is important for both safety and service life.
When installing a concealed cistern, the wall thickness, plasterboard or masonry construction, finished tile level and WC centre line must all be calculated together. An incorrect level or centre line makes fitting the WC difficult later on.
Technical installation details
| WC outlet | Usually a Ø110 mm PVC / PP soil pipe |
|---|---|
| Cistern supply | 1/2” water supply connection |
| Suitable systems | Wall-hung WCs, floor-standing WCs, concealed cisterns, close-coupled cisterns |
| Points to note | Centre line, finished floor level, frame installation, access panel and tightness |
Washing Machine Water and Waste Connection
For a washing machine connection, the water supply, waste discharge and appliance position must be planned correctly. The machine hoses must not be kinked, the waste connection must prevent backflow and the valve must be easy to reach.
If a washing machine is to be used in a bathroom, water splashing around the appliance, electrical safety and floor drainage must also be considered.
Technical installation details
| Water connection | Usually a 3/4” washing machine hose |
|---|---|
| Waste pipe diameter | Ø40 / Ø50 mm connection |
| Suitable applications | Bathrooms, utility rooms, plant rooms, kitchen utility areas |
| Points to note | Valve access, kinked hoses, backflow, electrical and water safety |
What should you consider when installing bathroom & WC plumbing?
1. Waste pipes must be laid at the correct fall.
An incorrect fall in the washbasin, shower, WC and washing machine wastes can cause odours, blockages and backflow.
2. Waterproofing must not be neglected.
Proper waterproofing must be applied in the shower area, around the floor gully and at wall–floor junctions.
3. Concealed cistern dimensions must be measured correctly.
The finished floor level, tile thickness, WC centre line and access panel position must be planned in advance.
4. Testing must be carried out before handover.
A pressure test of the water supply, a tightness check of the waste pipes and the trap connections must always be checked before finishes are applied.
Let’s prepare safe, long-lasting plumbing for your bathroom.
We will install washbasins, showers, WCs, concealed cisterns, washing machines and waste pipes so that they are leak-tight, accessible and compliant with standards.