Planning Rooftop Solar? Check the Loads First

PV arrays add 15–25 kg/m² to the roof. Not every existing roof can take it without a structural check.

Rooftop solar is one of the most requested retrofits. But modules, rails and mounting add roughly 15–25 kg/m² — on top of maintenance loads, some existing roofs are already near their limit.

Our recommended process: review the original calculation notes to check purlin and rafter reserves; if reserves are insufficient, locally reinforce purlins or switch to clamp-type mounts that avoid roof penetration. Never cut purlins or make unplanned welds during installation.

One often-missed detail: roof sheets under PV panels run hotter, so the coating class should be upgraded accordingly. A full assessment before retrofit costs far less than strengthening afterwards.