Sheet drains, featuring cuspated or dimpled plastic cores wrapped in geotextile fabric, serve a crucial role in managing water flow in various construction scenarios, from foundation walls to podium decks. The design of these drains, with either a single or double dimpled core, creates a void space, allowing water to flow freely, thereby reducing hydrostatic pressure on structures and providing effective drainage. However, understanding the difference between single and double dimpled drains can influence the success of your drainage solution.
Single dimpled or cuspated sheets have dimples on one side, with a flat surface on the other. These are typically positioned against a flat surface (like a foundation wall or a concrete slab), with the flat side against the structure and the dimpled side facing the soil or the fill material. The dimples create channels that guide the water away from the structure.
On the other hand, double dimpled or cuspated sheets, featuring dimples on both sides, provide an additional void space, allowing water to flow on both sides of the sheet. This design can be beneficial in situations where larger volumes of water need to be handled, such as podium decks and green roofs, where soil or fill material is on both sides of the sheet. In addition, double dimpled sheets can protect waterproofing membranes on walls from damage during backfilling, and provide an additional drainage path for any water that might get past the first layer. The redundancy in case of blockage or damage is another advantage of double dimpled sheets.
Now, let’s dive into the specifics of three sheet drain products we offer, based on the single or double dimpled design and thickness:
10 Single (10mm): With a high compression resistance of 500 kPa, this product is designed to withstand substantial loads without significant deformation. However, due to its smaller thickness, the flow rate is lower, making it suitable for applications where high load resistance is essential, and the expected water flow is relatively low.
20 Single (20mm): This product, being twice as thick as the 10 Single, offers the highest flow rate among the three. However, its compression resistance is lower. Thus, it’s suitable for scenarios where a high rate of water flow is expected, and the loads on the product aren’t excessive.
18 Double (18mm): This double-dimpled product strikes a balance between the properties of the 10 Single and 20 Single. With a compression resistance of 250 kPa and a high flow rate, it can provide drainage on both sides, making it useful in certain applications.
While these technical characteristics guide the selection process, the choice of the right product ultimately depends on the specific requirements of your project, including expected loads, expected water flow, and whether drainage is needed on one or both sides. As always, consulting with a geotechnical engineer or a similar expert can help you select the most suitable drainage solution for your specific situation, ensuring the longevity and success of your project.