ABG Extensive Green Roof with Roofdrain 25mm Reservoir Board

Extensive Green Roof comprises:

- Growing media:

ABG peat free media derived from sustainable, 100% recycled, UK sourced materials. Using a specifically developed growing media can help provide the right growing environment for the selected vegetation and also reduce the load on the roof. The growing media can also be adjusted to support specific design requirements like calcareous applications.

- Vegetation:

Specifically selected to suit the final finish requirements of the client / end user. On extensive green roofs, low maintenance varieties such as mosses, herbaceous plants, sedums, wildflowers and grasses tend to be used.

- ABG Roofdrain:

Geocomposite reservoir board with multidirectional drainage function suitable for use underneath substrate layers of 150 mm and below. It is particularly useful on pitched roofs due to the profile of the cone shaped cuspates.

ABG Roofdrain allows the storage of water within the cuspates of the HDPE core, whilst facilitating the efficient drainage of any excess water away from the roof. This helps prevent the growing media from drying out or from becoming waterlogged. When used within a green roof construction, it provides a versatile system for the collection of rainwater at the base of the growing medium and for the prevention of water pressure on the structural waterproofing, whilst still allowing oxygen and nutrients to get to the roots of the plants.

Roofdrain consists of three components bonded together to create a single product. A filter textile is bonded to the upper part of the reservoir board to provide a separation layer that filters particles and fines down to 100 microns (µm), whilst preventing the substrate from any ingression into the reservoir layer.

The core is perforated to allow excess water to drain through into the flow channels underneath, preventing pooling and oversaturation of the plants. Finally, a protection geotextile is bonded to the underside of the reservoir/ drainage board to protect the insulation / waterproofing layer onto which the Roofdrain is placed.

Features and benefits:

• Added protection for waterproofing layer
• Scores BREEAM points
• Reduces whole life costs of the building and energy usage
• SuDS design solution, acting as the first stage in the treatment train
• Creates a usable space
• Creates habitat to improve biodiversity
• Noise reducing
• Extracts pollutants and improves air quality