Drainage Board

Substrate cleaning: Clean the surface of the waterproofing layer thoroughly to remove all dust and debris.
Based on the slope direction of the planting roof deck or the location of the outlet, determine the overall drainage direction. Mark guideline according to the drawings for positioning, then apply the self-adhesive waterproofing membrane after the positioning lines are set, to finalize the location of the siphonic drainage channel.

Installation of siphon drainage channel: The siphon drainage channel is adhesively bonded and secured to the self-adhesive underlayment strip that has been laid according to the layout lines.
Lay the drainage board waterproofing composite geotextile with butt joints. Install it parallel to the predetermined drainage direction, with the overlap width complying with design or code requirements.
The long edges and short ends of the drainage board composite geotextile are joined and secured using dedicated self-adhesive waterproofing membrane strips with butt seams, forming an integral waterproof protection layer. For the geotextile overlap, a specialized adhesive is applied for bonding.
For geotextile-to-geotextile connections, seal the overlapped edge by bonding with a minimum overlap width of 100mm.

Install the vented inspection pipe: Install the pipe at locations specified in the drawings. (Process: Cut an opening in the siphon drainage channel - Install the vented inspection pipe - Install the dust cap).
Install geotextile over the siphon drainage channel. Overlaps between geotextile shall be bonded using specialized adhesive. (The geotextile laid on the siphon drainage channel has a roll width of 600mm.)
The siphon drainage channels are laid according to the design drawings, and the vented inspection pipe are installed at their specified locations. The installed geotextile filter layer and the drainage board composite geotextile together form an integral, relatively sealed filtration system.
Upon completion of the installation of all components including the drainage board composite geotextile, siphon drainage channels, and the vented inspection pipe, install the siphon pipes at the outlet locations indicated in the construction drawings.
Install the inspection well according to the construction drawings and connect it to the siphon pipe at the roof outlet location. The inspection chamber is connected to the stormwater inspection chamber via an overflow pipe. The installation of the siphon pipe and overflow pipe must be carried out concurrently with the excavation and construction of the project area's storm and sewage pipeline network.

Backfilling: Backfill soil promptly to prevent damage to the drainage board and geotextile by other trades. Construction machinery must not make direct contact with the drainage board.