6.3.5 Air-termination systems for roofs that can be accessed and walked on

Conventional air-termination systems, such as those secured with concrete blocks, cannot be installed on accessible roof surfaces. In order to nonetheless ensure standards-compliant external lightning protection, air-termination conductors can be laid either directly in the concrete or in the joints between the decks. When laying in joints, care must be taken to ensure that air-termination studs are installed as defined points of strike at the intersections of the lightning protection mesh. The mesh size of this air-termination system must not exceed the limits specified in chapter 4.1, Table 4.1.3 for the respective lightning protection class.

Provided that it is ensured that no people are on the roof during a thunderstorm, implementation of the aforementioned measures is sufficient. In this case, however, clear and clearly visible signage is required to inform people that they must leave the parking deck immediately in the event of a thunderstorm and must not enter it (see Figure 6.3.5.1).