Foundation earthing

Earthing material at a glance

The foundation earthing concept is the preferred method in new buildings with electrical installations. The earth conductor is embedded in the concrete foundation on the outside of the building and connected to form a closed ring.

Use of reinforcing steel in the concrete foundation

Reinforcing steel in the concrete foundation with a diameter of at least 10 mm can be used as an earth electrode. A highly conductive iron is connected to form a closed ring around the building using a clamp, crimp or other equivalent connection. Connection with binding wire is not permitted. It is important to mark the reinforcing bars before concreting to avoid confusion with normal reinforcement.

Earthing the foundation: Minimum requirements

A reinforcing steel with a diameter of 10 mm, which is connected around the building to form a ring, is sufficient for effective foundation earthing. This concept not only offers protection against corrosion, but also serves as an equipotential bonding conductor for all connections in the building.

Foundation earthing for buildings with a foundation trough

In the case of buildings with a foundation trough, it must be ensured that the foundation earth electrode is arranged in the floor of the outer trough. In the absence of a second tank, such as in Minergie houses, an additional spare earth electrode must be installed in the ground and connected to the foundation earthing every 15 m or at a distance from the down conductors (lightning protection).

Lightning protection concept and connection points

The connection points of the earthing can be used to discharge the lightning current if a corresponding lightning protection concept is in place and sufficient connection points are available. This ensures safe discharge of dangerous voltages and currents in the event of lightning strikes or atmospheric discharges.

These earthing methods not only provide safety, but also enable the efficient discharge of electrical currents to protect people, animals and property.