Ballasted mounting systems are widely used on flat commercial roofs where membrane penetration is undesirable or would void the waterproofing warranty. The system relies entirely on the dead weight of concrete blocks to resist wind uplift and lateral slide forces. Structural engineers verify that the roof structure can carry the combined weight of the mounting system, panels, and ballast blocks under all Eurocode load combinations.
Ballast weights are determined by the system supplier through wind load calculations specific to the site address, roof edge conditions, and array tilt angle. Perimeter zones near the roof edge experience higher wind uplift and require more ballast per panel. Solar Surveys Desktop Structural Roof Loading Reports assess whether the existing roof structure has adequate capacity for the total ballasted system dead load.