Roofdrain is a premium, geocomposite drainage solution specifically engineered for use in extensive and intensive green roof systems, designed to manage stormwater, retain moisture, and promote healthy vegetation growth. Developed for integration beneath green roof substrates, Roofdrain combines exceptional drainage performance with water retention capabilities, ensuring efficient rainwater runoff management while sustaining plant life in dry conditions.
Each Roofdrain product features a structured cuspated core bonded to high-performance geotextiles that filter fines and support the controlled movement of water. This dual-action structure allows water to drain quickly during rainfall while retaining moisture in built-in reservoirs for gradual release back to the root zone – making it ideal for urban greening projects, SUDS schemes, rooftop gardens, and blue-green infrastructure developments.
Widely specified by landscape architects, roofing engineers, local authorities, and green infrastructure contractors, Roofdrain products are suitable for use across commercial, public, and residential green roof projects. They can be laid directly under growing substrates and are compatible with a wide range of build-up systems. Available in varying thicknesses and capacities to suit specific loadings, roof gradients, and planting requirements.
Applications:
Extensive and intensive green roof systems
Podium decks and landscaped terraces
Blue-green infrastructure and SUDS
Biodiverse and wildflower roofs
Public buildings, schools, urban housing developments
Municipal and local authority-led green roof initiatives
Key Benefits:
Dual function: high-capacity drainage and water storage
Prevents waterlogging and root rot in planting layers
Enhances plant resilience in dry periods with stored moisture
Lightweight and flexible for easy installation and transport
Reduces stormwater runoff and supports biodiversity net gain
Compatible with root barrier membranes and filtration layers
Cost-effective and proven in long-term performance
Roofdrain Sizes & Reservoir Capacities:
Product Code Thickness Reservoir Capacity Roll Size
Roofdrain 20 20mm 5.5 L/m² 920mm x 50m
Roofdrain 25 25mm 4.3 L/m² 920mm x 50m
Roofdrain 40 40mm 12 L/m² 920mm x 20m
Roofdrain 60 60mm 23 L/m² 920mm x 15.2m
Roofdrain 60 does not have geotextile layer included
Installation is typically done by rolling the product out across the roof structure over the waterproofing layer, ensuring overlaps and upstands are in line with design specification. It may be used in conjunction with filter fleece, root barriers, and protection layers depending on roof design. Please Note:
This product is dispatched directly from our trusted supplier’s warehouse. While we aim to keep product availability as accurate as possible, we do not have live stock control for these items. Availability is subject to change, and delivery can take up to 15 working days, depending on stock levels at the time of order.
Tracking information will be provided where available, but please note this is dependent on the supplier’s shipping process. If you have any questions about lead times or delivery, our team is happy to help before you place your order.

Function: Sub-surface drainage + water retention layer for green roofs
Material: HDPE cuspated core + non-woven geotextile(s)
Thickness Options: 20mm, 25mm, 40mm, 60mm
Reservoir Capacity:
Roofdrain 20: 5.5 L/m²
Roofdrain 25: 4.3 L/m²
Roofdrain 40: 12 L/m²
Roofdrain 60: 23 L/m²
Roll Sizes:
20mm/25mm: 920mm x 50m
40mm: 920mm x 20m
60mm: 920mm x 15.2m
Installation: Laid directly under substrate layer on top of root barrier or waterproofing membrane
Weight: Varies by thickness; lightweight for ease of handling
Performance:
High flow rate capacity
Maintains root zone moisture
Prevents substrate saturation and erosion
Usage: Suitable for flat or sloped roofs, terraces, and podiums