Grass Grid Pavers on Rooftop Terraces: Building Load and Waterproofing

Structural Load Check

Before installing grass grid on a rooftop, confirm the building structure supports the added weight of wet soil, gravel and any furniture. Roof gardens are heavier than standard roof loads and may require structural assessment.

Waterproofing Protection

The roof membrane must be protected from puncture by the grid and gravel. Install a protective geotextile layer over the roof waterproofing before placing the drainage mat and grid.

Drainage Layer

Place a dimpled drainage board above the protection layer to channel rooftop runoff. The grass grid cells are then filled with lightweight growing medium, not heavy soil, to reduce dead load.

Related: grass grid and geotextile protection layer.