Photovoltaic systems are often installed on existing roofs of industrial buildings or larger residential complexes. If the roof structure is already damaged, is not designed for the additional weight of a PV system or is damaged during installation, this can lead to high subsequent costs. This is confirmed by the evaluation of the PV roof checks carried out by TÜV SÜD in 2023 on over 50 roofs of various properties.
The spectrum of roofs inspected ranged from tile-covered pitched roofs of detached houses to complex roof systems of industrial buildings and residential complexes with various types of roof waterproofing. It was found that only a quarter of the roofs were suitable for accommodating a PV system, while 8% of the roofs could not be fitted with PV modules for structural reasons. "Especially in the case of industrial buildings, the most economical solution is often sought for the roof system," says Andreas Dolipski, from the Construction Technology business unit of TÜV SÜD Industrie Service GmbH. "The result is usually a simpler and more cost-effective form of roof waterproofing." According to the TÜV SÜD expert, it is therefore important to carefully examine the existing structure, including the roof waterproofing and insulation, and the possible effects of the planned change of use, especially in the case of flat roofs, before installing a PV system.
