The main use of drainage systems is for soil drainage. However, they are increasingly being used in conjunction with gutter systems for rainwater infiltration. The drainage system that makes up such an installation is durable, lightweight and easy to install.

Drainage - function and purpose

Drainage is a system for draining the ground. Its purpose is to collect water lying in the ground and drain it to a place where it can be safely returned, such as a sewer, drainage ditch or rainwater storage tank. Such systems are used to protect the site from high groundwater levels, or rainwater lying on impermeable clay or silt soil. The operation of such an arrangement ensures that the ground is stable, does not become wet and is not washed away. In addition, it helps to protect the stability of the ground in the vicinity of building foundations.
An effective system for infiltrating rainwater into the ground can also easily be made from drainage pipes and fittings.
Combined with the building's guttering system, this is a simple and effective way of draining rainwater from roofs that is environmentally friendly and safe for the ground and building foundations.

The drainage system consists mainly of pipes

Unlined drainage pipe

This type of pipe is used in drainage systems for sections where the pipeline does not collect or infiltrate water. It is a solid pipe that is used for sections of the installation such as those draining the collected water from the building foundations.

Borehole drainage pipe

This is the basic type of drainage pipe. It is a single layer corrugated pipe with openings around the circumference of the pipe. It is used for the construction of the active drainage section and, thanks to the cut-outs, allows both the collection of water from waterlogged ground and the infiltration of rainwater drained from the building gutters.

Geotextile covered drainage pipe

This is a drainage pipe with an additional filter lagging wound around the outer layer of the pipe. It has the same function in the system as a drainage pipe without the casing, although the casing can be used in more difficult soil conditions. The geotextile lagging is designed to keep fine soil fractions out of the pipe, thus preventing the drainage system from silting up.

PP 700 lagged drainage pipe

This is a drainage pipe with a thicker and denser lagging on the outside of the pipe. It is designed for use in particularly difficult soil conditions, such as clay soils.

Fig. 1: PVC 100 drainage pipe with geotextile cover - 50 m coil

Drainage fittings - linking the drainage system

• Drainage socket - is used to join together two sections of drainage pipe of the same diameter.
• Drainage connectors - are used to connect drainage pipes to pipes or fittings of other systems, for example sewer pipes.
• Drainage elbow - is used to join two sections of drainage pipe of the same diameter at an angle to make a bend in the pipe.
• T-piece and drainage quadrant - are used to create branches in the drainage system. Drainage tees can also be reduction tees, allowing pipes of different diameters to be joined. T-pieces have three sockets for connection to the drainage pipe, while quadruples have four.
• Drainage plug - is used to close the end of the drainage pipe. The cap is solid and has no holes.
• Drainage reduction - The drainage reducer is used to connect two sections of drainage pipe of different diameters.
• Drainage termination - is used to protect the exposed end of the drainage pipe. If the drainage pipe discharges collected water into a ditch, for example, the drainage termination reinforces the outlet of the pipe and protects it from crushing. With its integrated grate, the termination also protects the drainage system from the entry of rodents.

All drainage fittings connect to the pipe via special clips that catch the pipe notches and prevent them from slipping out.

Additional accessories for the construction of drainage systems

Drainage systems do not only consist of pipes and fittings. Manholes or additional finishing materials can also be useful.

Geotextile

Geotextile is available in rolls of various widths. It is an extremely useful material when laying a drainage system. It can be used to wrap the drainage pipe itself and also to make filter layers around the backfill.

Manholes

In drainage systems, manholes can fulfil various functions, e.g. inspection, drainage, settling. Manholes can be finished articles or consist of corrugated shaft pipes, covers for them and other ancillary articles, such as in-situ seals that allow the drainage pipe to enter the manhole.

Sill traps

They are used in infiltration systems. They serve as a transition from the gutter system located on the building to the underground infiltration pipe. Depending on the direction of rainwater drainage from the settling tank, we distinguish between bottom settling tanks and side settling tanks.

Fig. 2: Drainage T-piece DN 100/100/45 PP orange

Using the above products, it is possible to build complete drainage and rainwater infiltration systems into the ground. Most of the system components are press-fit and do not require additional seals or special tools. These systems not only make it possible to secure and stabilise the ground, but their use is also ecologically sound, as they help to maintain the correct water cycle in nature even on paved areas.