Grass Grid Pavers on Rooftop Parking: Load and Drainage Considerations

Rooftop Applications for Grass Grid

Grass grid pavers on rooftops offer a lightweight, permeable surface for emergency access, pedestrian use and occasional vehicle parking. Unlike concrete paving, the plastic grid cells support soil and vegetation while allowing stormwater infiltration.

Load Distribution

Before installing grass grid on a rooftop, confirm the structural live-load capacity of the deck. For vehicular rooftop access, geogrid reinforcement beneath the drainage layer is recommended to distribute wheel loads and prevent differential settlement of the growing medium.

Drainage Layer Configuration

A rooftop grass grid system typically requires: a root barrier membrane, a drainage/composite board layer, a filter fabric, and the plastic grid filled with engineered soil. The drainage layer prevents waterlogging on the waterproofing membrane.

Related products: drainage board for the sub-surface layer, and geogrid for load reinforcement.