Wastewater & Drainage Systems
Quiet, Odour-Free and Safe Drainage Infrastructure.
Professional drainage and sewerage solutions for removing wastewater from washbasins, showers, WCs, kitchens, laundry areas and plant rooms safely, quietly and without odours.
Request a Quote for Your Project →A wastewater system is the infrastructure that safely removes foul water from a building.
Drainage pipes installed without the correct diameter, fall, venting and connection details can cause odours, blockages, noise and backflow.
The wastewater and sewerage system carries water from washbasins, showers, WCs, kitchen sinks, dishwashers, washing machines, floor gullies and technical drains to the main sewer.
Pipe diameter, fall, bend angles, vent pipes, access covers, trap connections and acoustic insulation must all be assessed together. As faults usually end up hidden under finishes, later repairs are difficult and costly.
Which details matter in a wastewater and sewerage system?
Internal drainage, main WC drains, kitchen wastes and sewer connections are described below, with technical dimensions, pipe types and installation details.
Bathroom, Washbasin and Shower Waste Pipes
Bathroom wastes such as washbasins, showers, baths and floor gullies must be connected to the main waste stack with the correct diameter and fall. Odour-sealing traps, maintenance access and sufficient flow velocity are important for these pipes.
In shower and floor gully drains, too shallow a fall causes water to stand, while too steep a fall causes water to separate quickly from solids and increases the risk of blockage. The floor level and finished tile level must therefore be considered together during installation.
Technical installation details
| Pipes used | PP, PVC, HT pipe, low-noise drainage pipe, cast iron pipe options |
|---|---|
| Typical diameters | Washbasin Ø40/50 mm, shower Ø50 mm, floor gully Ø50/75 mm |
| Fall | Usually 1.5–2%; varies according to the project and pipe diameter |
| Points to note | Odour prevention, waterproofing, gully height, cleaning access |
WC and Main Drain Pipes
The WC soil pipe is one of the most critical drainage lines in a building. The WC outlet, concealed cistern or floor-standing WC connection, connection to the main stack and venting details must be executed correctly.
Because a WC produces high peak flows, the pipe diameter, choice of bends and stack connection are particularly important. Sharp bends, insufficient diameter or an incorrect fall can quickly lead to blockages and backflow.
Technical installation details
| WC outlet | Usually Ø110 mm PP / PVC / HT pipe |
|---|---|
| Stack connection | Must be connected to the main soil stack at a suitable angle |
| Risks | Blockages, backflow, trap siphonage, odours and noise |
| Points to note | Centre line, pipe fall, number of bends, access cover, venting |
Kitchen Wastes and Greasy Wastewater
Kitchen wastes carry wastewater from the sink, dishwasher and, in some cases, a water treatment unit. Build-up of grease, food residue and detergent in these pipes increases the risk of blockage.
In restaurants and commercial kitchens, the use of a grease separator should be considered. In domestic kitchens, the right trap, suitable pipe diameter and cleaning access ensure long-term reliability.
Technical installation details
| Area of application | Domestic kitchens, restaurant kitchens, cafés, dishwashing areas, preparation areas |
|---|---|
| Typical diameters | Domestic sink Ø50 mm; commercial lines Ø75 / Ø110 mm depending on the project |
| Special equipment | Grease separators, stainless steel channel gullies, access covers, traps |
| Points to note | Grease build-up, odours, blockages, trap connection, cleaning access |
Sewer Connection and Main Drain
Internal wastewater pipes must be connected safely to the main sewer. This connection requires the correct fall and a suitable diameter for both the internal installation and the external drainage.
For main drains, the risk of backflow, manhole invert levels, frost depth, the external pipe route and maintenance points must be planned together. Buildings with basements in particular may require backflow valves or pumped drainage solutions.
Technical installation details
| Main drain diameters | Ø110 mm, Ø160 mm, Ø200 mm and larger diameters as required by the project |
|---|---|
| External drainage pipes | PVC-U, PP sewer pipe, pipes with external load resistance according to SN class |
| Maintenance points | Manholes, access covers, inspection chambers |
| Points to note | Level differences, frost depth, risk of backflow, traffic loads, maintenance access |
What should you consider when installing a wastewater and sewerage system?
1. The pipe diameter must be selected correctly.
Washbasin, shower, kitchen and WC drains cannot all use the same diameter. Each point of use has a different flow rate and type of wastewater.
2. The fall must be correct.
Too shallow a fall causes water to stand, while too steep a fall can leave solids behind in the pipe.
3. Odour prevention must not be overlooked.
Without a trap, vent pipe and correct connections, sewer odours can return to the living space.
4. Cleaning access must be provided.
Providing access covers or manholes on long horizontal runs, at changes of direction and at main connections makes maintenance easier.
Let’s plan a quiet, odour-free and safe drainage system for your building.
We will install washbasin, shower, WC, kitchen, laundry and main sewer pipes with the correct diameters, correct falls and leak-tight connections.