" />Drainage boards (also called dimpled membranes or drainage mats) are geosynthetic composites that manage subsurface water. They combine a drainage core with a filter layer.
How Drainage Boards Work
The dimpled or studded core creates an air gap that channels water away from the structure. A non-woven geotextile filter layer on top prevents soil particles from clogging the drainage path. Water flows horizontally through the dimples to perimeter drains.
Common Applications
- Basement walls: Reduces hydrostatic pressure on foundation walls
- Rooftop gardens: Protects waterproofing and drains excess irrigation water
- Tunnel lining: Collects seepage behind tunnel liners
- Retaining walls: Relieves built-up water pressure behind wall backfill
- Plaza and podium decks: Drains landscape soil above structural slabs
Material Specifications
HDPE drainage boards typically range from 8mm to 30mm in dimple height. Higher dimple heights provide greater flow capacity. The geotextile filter layer is usually 200g/m non-woven fabric.
Installation Tips
Install with the dimpled side facing the structure or subgrade. Overlap joints by at least 100mm. Secure with mechanical fasteners on vertical walls. Always ensure the drainage outlet is clear and unobstructed.
Explore drainage board options and related geosynthetic products at Yunnan YN Building Materials.
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