详细内容：
Construction techniques and precautions for drainage boards
Clear the garbage, cement and level the site to ensure there are no obvious lumps. The outdoor garage roof and rooftop garden need to have a slope of 2 to 5 inches. This enables the water in the drainage board to be concentrated in nearby water pipes or nearby urban sewers.
2. The bottom layer of the basement is impermeable and is located above the foundation. That is, a layer of drainage board is made before the floor is fabricated. The circular platform is lowered and surrounded by blind ditches, preventing groundwater from coming in. Water naturally seeps into the space of the drainage board. Enter the surrounding blind ditch and then flow into the collection puddle through the blind ditch.
3. The inner walls of the basement are impermeable to water. Drainage boards can be laid on the main wall of the building, and the circular protruding platform should face the main wall. Use single-wall or steel mesh cement to protect the drainage board outside the drainage board, allowing the space of the seepage board outside the wall to directly flow into the blind ditch and the direct water collection pit.
4. When laying drainage boards in any area, it is essential to note that soil, cement, yellow sand and other garbage must not enter the front space of the drainage boards to ensure that the space of the drainage boards is not obstructed.
5. When laying drainage boards, protective measures should be taken as much as possible. The ground or outdoor garage drainage boards should be laid as soon as possible, and the backfilling work should be done promptly to prevent strong winds and disorderly drainage boards from affecting the laying quality. The waterproofing of the basement and the inner walls should be done as soon as possible to prevent the drainage boards from being damaged by people or objects.
6. The backfill soil is clayey soil. It is ideal to cover the geotextile with 3 to 5 centimeters of yellow sand, which is conducive to the filtration of the geotextile. If the backfill is nutrient soil or light soil, there is no need to lay a layer of yellow sand. The soil itself is very loose and easy to filter.
7. When laying the drainage board, remove 1-2 support points from each side to the right. The two bottom plates can also be touched together. The top is connected with geotextile. As long as there are no drainage channels for the soil to enter the drainage board, the drainage can remain stable.