When should a drainage channel be installed on the patio?

When a patio is built, the ground is sealed to a greater or lesser extent. Depending on the type of paving, the water can seep away less quickly or not at all. Puddles of water form. An inherent slope of the patio can allow water to flow directly into the surrounding area, e.g. into lawns. Depending on the nature of the lawn, puddles of water can also form here due to excessive rainfall. A drainage channel drains the water, prevents puddles of water on the patio and protects the lawn from excessive amounts of water.
Drainage channel HYDROline PRO in garden in Rheinböllen
Drainage channel HYDROline PRO in garden in Rheinböllen

Where should the drainage channel be positioned on the patio?

Exactly where the drainage channel is installed depends on several factors. If the patio is to remain barrier-free or without a slope, the channel should be installed directly along the house wall to prevent water from entering the house. If the surface is allowed to slope, the channel can be laid anywhere along the patio. To ensure that the water flows in the direction of the channel, there should be a slope of at least 2% of the patio surface.

Where should the water flow to?

Underground pipe

Drainage channels can be connected to the underground pipe to remove the water. The waste water or rainwater, e.g. from the drainage channel, drains into the sewer system via the underground pipe. The pipes are located at a depth of at least approx. 80 cm.


A soakaway is a depression in the ground. The rainwater collects in the shaft and slowly seeps through the ground and over the walls. Compared to a swale, less space is required and the water is only channelled underground. The shaft can be of any size. However, it usually has a depth of 1 metre and a diameter of 100 to 400 mm.


A swale is a shallow depression in the ground and is ideal if the water cannot seep away so quickly. A trough for the garden, for example, is 30 cm deep and is at least 1 m above the groundwater level. A good seepage capacity is a basic requirement so that the water disappears again within a day. The area is 10 - 20% of the connected area. Comprehensive information should be obtained before installing a swale. Incorrectly calculated swales can lead to major problems.

Installation of a Drainage Channel

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