Drainage and water retention boards are a type of drainage board. They are block-shaped, waterproof, and water-retaining, and are often used in rooftop greening and indoor planting. Drainage and water retention boards are lightweight boards made of high-density polyethylene (HDPE) or polypropylene (PP) through heating and pressurization. They create drainage channels with a certain degree of three-dimensional spatial support rigidity while also retaining water.
This type of board has both water storage and drainage functions. The board has extremely high spatial rigidity and its compressive strength is significantly better than similar products (which can be verified by on-site testing). It can withstand high compressive loads of over 400 kPa and can also withstand extreme loads from mechanical compaction during the backfilling process of the planting roof.
Features
1. Easy construction, simple maintenance, and economical.
2. High load-bearing capacity and durability.
3. Ensures rapid drainage of excess water.
4. The water storage section can store some water.
5. Provides sufficient water and oxygen for plant growth.
6. Lightweight and provides excellent roof insulation.
Applications
Used for rooftop greening, underground parking roof greening, city squares, golf courses, sports fields, sewage treatment plants, public building greening, plaza greening, and roadside greening projects within industrial parks.
Construction Notes:
1. When used in garden flower beds, troughs, and planters, replace conventional materials (such as filter layers composed of expanded clay, pebbles, or shells) directly with water-retaining boards and filter geotextiles.
2. When used for greening hard surfaces such as new or old rooftops or underground engineering slabs, clear debris from the site before laying the drainage boards. Install a waterproof layer according to the design drawings, then slope the surface with cement mortar to ensure a smooth surface without obvious unevenness. Arrange the drainage boards in an orderly manner; no additional drainage ditch is required within the laying area.
3. When used as a building sandwich slab, lay the drainage boards on the roof concrete slab. Build a single wall or protect it with concrete, allowing groundwater seepage to flow through the gaps in the drainage boards into the drainage ditch and sump.
4. The drainage boards should be spliced together around their perimeter. The gaps during installation serve as drainage channels for the lower layer. The geotextile filter and moisture-retaining layer above should also be overlapped during installation.
