Green Roof Water Retention and Drainage Tray

This green roof water retention and drainage tray creates a functional layer beneath the growing medium. Its shaped reservoirs retain part of the rainfall for vegetation, while drainage paths allow excess water to move toward roof outlets and air spaces support the assembly.

Water Retention and Drainage Tray Functions

Role in the Green Roof Build-Up

This component is normally installed above the protection or root-resistant layer and below the filter geotextile. It should be treated as one part of a coordinated roof build-up rather than a standalone waterproofing or structural solution. The final assembly must maintain drainage continuity and allow roof outlets and inspection points to remain accessible.

Design and Installation Considerations

• Confirm roof falls, outlet locations, required retention capacity, growing-medium depth and the complete system load.
• Prepare the substrate and adjacent layers so they are clean, stable and free from sharp projections.
• Follow the project drawings for orientation, overlaps, edge details and outlet treatment.
• Protect completed areas during the placement of subsequent layers and growing medium.
• Inspect the assembly before covering it and retain records of concealed work where required.

Typical Applications

Green Roof Water Retention and Drainage Tray can be considered for extensive or intensive green roofs, roof gardens, podium landscapes and other planted build-ups where its stated function matches the project design. Selection should be based on the complete system specification, roof geometry, vegetation, growing-medium depth, rainfall, drainage strategy and maintenance plan.

Project Support

For product selection and quantity planning, provide the roof plan, build-up detail, total area, outlet layout and project performance requirements. We can then coordinate the product format, packing and supply information while the project designer confirms the complete waterproofing, drainage and structural design.