The Similarity And Difference Between Drainage Board and Drainage Sheet
In recent years, the application of drainage board and drainage sheet has become more and more widespread in the roof greening projects, the effect of which is also more obvious than the gravel and ceramsite drainage. But what is the similarity and difference between the drainage board and drainage sheet?
Similarity:
Both types of drainage products have a concave-convex hollow rib structure, which can quickly and effectively drain rainwater, greatly reducing the hydrostatic pressure of the waterproof layer.
Difference:
Drainage Board: it is injection molded from polyethylene plastic with a size about 500mm by 500mm, which has a variety of functions such as water storage, drainage, ventilation, thermal insulation and so on. When used together with geotextiles, it can avoid the soil blocking the water storage cups and drainage channel, , forming a complete storage and drainage system, which is widely used in urban gardening and greening projects, which will not affect the roof load capacity, and can provide the necessary water to the plants in the dry seasons.
The PVC drainage sheet is normally with a size about 1.7 meter by 18 meter. It has strong root resistance. Due to the high density, the PVC drainage board has a strong rooting property, and the thickness of the membrane can be adjusted according to the requirements of the root to achieve the effect of separating the roots and resisting tearing. The drainage sheet normally one works with only function, either water drainage, or water storage. This is the biggest difference from the drainage board.
The high compressive strength of PVC drainage sheet is 1.5 times of the same thickness of PS and 2.5 times that of HDPE material. The compressive strength of the 0.7mm thickness drainage sheet is above 300kpa, while the compressive strength of PS and HDPE materials of the same thickness is only about 150kpa. Due to its unique rib design, the car will not flatten any of the support columns when it drives straightly on the top. This is not possible with other PS and HDPE materials.
