Drainage tube: which diameter is necessary?

Again and again there is uncertainty about the size of drainage pipes needed. The diameters that are available at all, and which ones are most commonly used, can be found in this article. On how the design of a drainage has to be done professionally.

Possible sizes for drainage pipes

As a rule, drainage pipes with a diameter (= nominal width NW) of 100 mm are used. They fit in most cases.

However, drainage pipes are available in various diameters ranging from 50 mm to 200 mm. In addition, there are some - isolated - some special diameter for special designs. Sizes below 70 mm are generally not recommended, as the small pipe dimension may under some circumstances make the pressure too high.

cut lengths

Please note that you may only use so-called "rod products" for drainage of buildings! The flexible yellow pipes are only approved for the agricultural area and the garden, but not for drainage of buildings.

The pipes must be laid in a straight line and at the right slope. Every change of direction requires a shaft. For right-angle connections there are 90° connectors for the pipes.

If flexible pipes are used, the drainage will not work and may flush itself. Then often threaten moisture damage with severe consequences on the building.

Basis of assessment for drainage pipes

For the selection of the diameter (the nominal size), the accumulating amount of water to be discharged is decisive. This requires an assessment of the entire situation at the construction site.

The amount of water that usually occurs as surface water and can accumulate to the maximum can be determined by a specialist after an on-site inspection. Thereafter, a drainage can then be dimensioned correctly planerisch.

As a layman one can estimate the expected flow through a drainage usually difficult. You must take into account

  • surface water
  • leachate
  • stratum water
  • any other sources of water that may be present

Professional planning

The planning is carried out professionally in accordance with the specifications of DIN 4095. There, a design method for drainage systems is described in detail. A distinction is made between "normal case" and "special case". However, the calculation needs to be precise about different values ​​and execution details in order to be fully executed.

Tips & Tricks

Even if pumps have to be installed, the flow rate as an assessment basis is important and should be estimated as accurately as possible. After the flow rate, the pumps are then dimensioned accordingly.

Video Board: SIZE MATTERS - How BIG is Your Pipe?