MP-B23C is an HDPE green roof water storage board that combines controlled drainage with a small water reserve beneath the growing medium. Its 410 × 410 × 23 mm interlocking modules help distribute retained water across the planted area while allowing excess rainfall to move toward roof outlets. This function is useful where the design needs both drainage protection and short-term moisture buffering.
Water Storage Function in a Green Roof
A green roof must drain safely after heavy rain, but rapid discharge can also leave the growing medium dry between rainfall or irrigation cycles. MP-B23C provides a 2.0 L/m² retention value in the original product data. The retained volume is not a replacement for a designed irrigation system; instead, it acts as a supplementary buffer within the roof build-up.
The board typically sits above the protected waterproofing layer and below the specified filter fabric and growing medium. It can be considered for planted roofs, podium gardens, landscape decks and other areas where water management must be coordinated with vegetation requirements. For projects that need complete planting containers rather than a loose drainage layer, see our modular green roof trays.
MP-B23C Technical Data
| Property | Value |
|---|---|
| Item No. | MP-B23C |
| Color | Green |
| Module size | 410 × 410 × 23 mm |
| Unit weight | 1,600 g/m² |
| Material | HDPE |
| Pressure strength | 300 kN (original technical table) |
| Hardness | 86 |
| Water drainage | 85% |
| Vertical circulation capacity | 20 cm³/s |
| Water retention | 2.0 L/m² |
| Packing | 45 pcs/bundle; approximately 0.6 m³/bundle |
| Indicative loading | 3,200 m²/20 ft; 6,700 m²/40 ft; 8,450 m²/40 HQ |
Design and Installation Notes
- Confirm roof falls, outlet positions and overflow routes before installation.
- Protect the waterproofing membrane and remove debris that could cause punctures.
- Interlock adjacent modules and cut neatly around penetrations and drainage points.
- Install the specified filter fabric before placing growing medium.
- Coordinate retained water, irrigation, plant selection and saturated roof loading with the project designer.
Project Images
Request Project Support
Send the roof area, section drawing, growing-medium depth, drainage layout, irrigation concept, design loading and destination to our project team. We can help calculate the module quantity and prepare packing and shipping information for your project.