Drainage – Traditional Green Roof Systems

The drainage layer is an important component within traditional green roof systems, contributing significantly to their overall efficacy and resilience. This layer fulfils a dual purpose, storing water and facilitating efficient drainage. Its multifaceted functionality ensures optimal conditions for the vegetation layer above while mitigating potential water-related issues.

During periods of precipitation, the drainage layer efficiently captures and stores water, preventing saturation and waterlogging within the substrate. This reservoir of water serves as a vital resource during drier spells, allowing the vegetation to thrive by accessing stored moisture. Moreover, by preventing excess water accumulation, the drainage layer safeguards against structural strain and potential damage to the roof.

Furthermore, the drainage layer plays a crucial role in promoting the aeration of plant roots. Facilitating the passage of air through the substrate prevents the soil from becoming compacted, ensuring sufficient oxygenation for healthy root development. This aeration not only fosters the vitality of the vegetation but also enhances the overall ecological benefits provided by the green roof.

Essentially, the drainage layer is a cornerstone of traditional green roof systems, harmonising water management and plant health. Its efficient design and functionality contribute to the sustainability and longevity of green roofs, making them a valuable asset for eco-conscious projects and urban landscapes.

For extra protection of the roof’s waterproofing membrane, the Protective Cover can be applied before the Drainage layer is rolled out.

Please note that when using a gravel border, extra drainage is required to sit beneath the gravel.


£13.30ex VAT per m2

Your choice of drainage will depend on the structure of the roof. When using a gravel border, extra drainage is required to sit beneath the gravel.

FS-Drainage Type 20R 20 mm_EN