Ground Drainage & Drainage

A well-functioning system below the ground surface is crucial for preserving the load-bearing capacity of a property and keeping basement walls dry. By combining the right ground drainage with well-thought-out drainage and stormwater management, rain, melt and groundwater are led away before they penetrate the foundation of the house or create flooding on the property.

The difference between ground drains and drainage

Although the products are often buried close to each other, they have two distinct functions that should never be confused or connected together in the wrong way:

• Ground drain pipes (smooth pipes): The reddish-brown, tight pipes are used to transport wastewater from the house or to direct rainwater from downpipes and gutters to a stormwater well or municipal connection. They must be tight and prevent water from leaking into the surrounding soil.
• Drainage pipes (perforated pipes): These pipes have small slots or holes along the sides to collect excess water from the soil around the house foundation and transport it away. They are always laid in draining gravel surrounded by non-woven fabric to avoid clogging.

Important factors when choosing components

1. Pipe class and load (SN classes): For ground drain pipes, the classification (usually SN4 or SN8) indicates how much soil load the pipe can withstand. SN8 is generally recommended for deeper installation or under surfaces with vehicle traffic, such as garage driveways and roads.
2. Dimensioning: The standard dimension for ground drainage from single-family homes is often 110 mm, while larger collection pipes may require 160 mm or more. Drainage pipes are dimensioned according to the site's soil conditions and the amount of incoming water.
3. Supplementary wells and cassettes: To enable flushing and inspection, drainage wells with sand traps and inspection wells are installed. If there is limited possibility of drainage into the municipal network, stormwater cassettes can be used for local infiltration on your own site.

The right choice of materials and careful preparation during excavation and backfilling reduces the risk of future subsidence and costly moisture damage to the property.