Water retention drainage boards should provide the functions defined by the green-roof or landscape design. water retention drainage boards need a clear description of stored-water volume and the route for excess water. Retention is not automatically beneficial at every depth or with every planting medium.

A proposal using roof garden drainage mats may emphasize another drainage arrangement. Keep comparison of the complete build-up visible. This guide focuses on interpreting retention claims and coordinating stored water, outlets and inspection without attributing a guaranteed plant result to one board.

Define the stated retention value

Ask what conditions and orientation are represented by the product's water-storage figure. Record the model and measurement basis. A nominal cavity volume should not be confused with usable storage in every installed arrangement. The landscape reviewer needs a clear definition to compare the board with the proposed medium and irrigation plan.

Understand overflow from the layer

Show how excess water passes to drains and how the filter interfaces with those paths. The design should distinguish intentional retention from unintended ponding. Keep outlets accessible and free of media. A reservoir feature cannot compensate for an incomplete discharge detail elsewhere in the roof build-up.

Coordinate planting requirements

Identify vegetation, media depth and maintenance provisions. Assess the board within those conditions rather than treating retained water as a substitute for irrigation planning. If planting or growing medium changes, review the drainage and retention arrangement together. The purchaser should not make horticultural promises from a single catalogue value.

Check dimensions and roof loads

Provide the complete layer section and relevant wet loading information. Review board depth and applicable compression evidence against the project requirements. Increasing retention or thickness can alter levels and weight. Keep any substitute subject to coordinated approval rather than accepting it solely because it claims a larger stored-water figure.

Request defined data

Send Suneco New Materials the intended retention function, layer section and outlet layout. Ask for model-specific storage and flow descriptions. A clear offer makes it possible to evaluate the board's two functions separately while retaining one coordinated landscape system.