PVC drainage boards use a patented design with cross-shaped support columns and additional central top columns. By utilizing the large surface area of the support columns and the arrangement of the central top columns, they ensure that the geotextile does not sag after backfilling, leaving sufficient space for smooth drainage. Additionally, the cross-shaped support columns are reinforced with eight sets of ribs, greatly increasing their compressive strength. The product has a fixed width, while the length can be customized according to requirements. It is easy to install, and once installed, it forms a new waterproof layer and root barrier layer.