Lightning Protection and Earthing: A Risk-Based Approach

Protection begins with risk

Lightning protection is not only a rooftop conductor. The strategy considers the building, its location, height, occupancy, incoming services and the consequences of damage or interruption. Sensitive equipment and critical operations may justify protection beyond basic structural safety.

A risk-based approach helps the client understand why air terminals, down conductors, earth electrodes, bonding and surge protection must work as one system.

Create a continuous path to earth

The external system intercepts a strike and conducts current safely to the ground. Routing should minimise dangerous side-flashing and avoid conflicts with façades, services and access. Earth electrodes then dissipate current under site-specific soil conditions.

Connections that become inaccessible or corrode can undermine the system. Test points, compatible materials and inspection access should be detailed from the beginning.

Bond services and protect equipment

Metallic services entering a building can introduce dangerous potential differences. Equipotential bonding reduces that risk, while coordinated surge protective devices limit transient overvoltage reaching electrical and electronic equipment.

Protection devices must be selected and arranged in stages. Installing a single device without considering upstream exposure and downstream sensitivity can create a false sense of security.

Verify, document and maintain

Earth resistance testing, continuity checks and visual inspection provide evidence that the installed system is complete. Results should be recorded at commissioning to establish a baseline for future maintenance.

Alterations to roofs, solar installations or incoming services can change the protection system. Periodic review keeps the strategy aligned with the actual building rather than the original drawings alone.