Green Bridge 

Green Bridge, Roofdrain, A556 Knutsford to Bowdon, Cheshire, UK

Project Information

Client:Highways England
Contractor:Costain
Consultant:Capita
Products:Roofdrain 40S1RXSSC3h, Deckdrain
Quantity:450m2
Benefits:- Supplied as one product allowing fast installation and reduced construction time
- Light and easy to cut to shape
- High water storage capacity for tree growth
- High strength resists trafficking


Project Description

The A556 Knutsford to Bowdon Green Bridge is one of the seven bridges on the £192M Highways England strategic road scheme, constructed to improve links to Manchester Airport from the M6. This unique structure crosses the road south of the A50 at Mere and is the first ever green bridge constructed on the Highways England Network. It was part of the environmental mitigation measures for the local community providing a natural wooded connectivity over the A556 for farm animals and pedestrians.

The Challenge

Minimising the environmental impact included carbon footprint reduction in both the design and the construction for the whole site. The design aim was to plant trees over the bridge as suitable environment for wildlife. These trees require a depth of growing media along with sufficient water supply to sustain a strong root system and tree canopy.

The challenge was to minimise the dead load to avoid increasing the bridge structure cross section whilst providing sufficient nutrients, water and soil structure for the trees the flourish. Access on the bridge is restricted and installation of any chosen product should be easy and quick to place.

The Solution

Roofdrain drainage geocomposite was chosen as a combined water attenuation and drainage layer reducing the depth of soil usually required to sustain the desired plants and trees to 600mm. Roofdrain is a lightweight, robust, geocomposite water retention and drainage product which provides a complete modular system, easy to lay and cut to the surface profile of the bridge. Roofdrain is comprised of a protection geotextile which allows it to be placed directly onto the bridge deck waterproofing, an upturned cuspated core which holds the water overlain with a filter geotextile to prevent soil filling the cups. This is backfilled with growing media and planted.

ABG Roofdrain drainage geocomposite used for a green bridge system

ABG Roofdrain – bonded geocomposite with upper filter geotextile and basal protection geotextile

The ABG Service

ABG, also a leading green roof provider, assisted with the specification to provide an optimum design for the bridge. ABG’s Roofdrain drainage geocomposite was shipped to site on one of their own FORS accredited vehicles, in line with the sites’ award winning safety goals for site and public personnel. ABG Deckdrain was supplied for all the structures on the site as an alternative to back of wall drainage stone. This contributed to the 120 tonnes of reduced Carbon attributed to reduced vehicle movements on the site.

Contact ABG today to discuss your project specific requirements and discover how ABG past experience and innovative products can help on your project.

Growing media being placed onto the Roofdrain drainage layerPlacing of 600mm of growing media over the Roofdrain drainage geocomposite
First Green Bridge for Highways EnglandFirst Green Bridge for Highways England
Roofdrain is a geocomposite with three components laid directly on bridge deck waterproofing layerRoofdrain is a geocomposite with three components laid directly on bridge deck waterproofing layer
A556 green bridge project


Roofdrain

Roofdrain is designed for use in extensive green roof systems. It provides both drainage and attenuation in a convenient, lightweight and cost effective system.

more...

Roofdrain drainage geocomposite for green roofs, blueroofs and roof SuDS attenuation
 

Products

Roofdrain

Roofdrain is designed for use in extensive green roof systems. It provides both drainage and attenuation in a convenient, lightweight and cost effective system.

more...

Roofdrain drainage geocomposite for green roofs, blueroofs and roof SuDS attenuation
 

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