Green RoofSystems

Green roofs are a fully integrated roofing solution, combining waterproofing, drainage and planting within a coordinated build up. Developed for both new build and refurbishment applications, Blackdown green roof systems are engineered to support environmental and performance requirements and targets whilst maintaining the integrity of the roof structure. 

Specification should align with recognised industry guidance, including the GRO Code of Best Practice, to ensure compliance with environmental and performance requirements. Green roofs contribute to sustainable drainage strategies (SuDS), support biodiversity and environmental objectives such as Biodiversity Net Gain and BREEAM ratings and deliver long term roof performance within the overall building envelope.

Benefits of a Green Roof

• Provides substitute habitats to support wildlife conservation and increase biodiversity
• Supports SuDS strategies by absorbing rainwater to help mitigate flooding and reduce rainwater runoff
• Improves surrounding air and water quality through the absorption of CO₂ and release of oxygen into the atmosphere
• Reduces the urban heat island effect, lowering surrounding temperatures
• Vegetation filters atmospheric pollutants and particulate matter
• Creates recreational space in urban areas 
• Improves wellbeing of building occupants 
• Reduces energy consumption of the building
• Increases building value
• Limits noise transfer
• Increases the life expectancy of the waterproofing membrane

Design Considerations

Key design considerations include ensuring the roof structure is capable of supporting the weight loadings associated with the green roof build up (including saturated conditions), provision of effective drainage of excess rainwater and safe access for ongoing maintenance.

Waterproofing systems must provide long-term durability and root resistance and be verified as suitable for use within a green roof build up by British Board of Agrément certification, with Alumasc systems such as Derbigum and Euroroof reinforced bituminous membranes, Hydrotech MM6125 hot melt waterproofing, Caltech cold applied liquids and Aluply single ply membranes ensuring compatibility and long-term performance.