attenuation systems

Stormwater management and flooding pose significant risks in urban settings.  Blue roofs have evolved as an innovative technique for storing rainwater, decreasing flood hazards and supporting sustainable development. However, misconceptions about blue roofs can cause design issues. Kevin Bohea, Manging Director of ACO Building Drainage, shares five recommendations for de-risking blue roof projects.

1.    Understand what a blue roof really is 
It should be noted that blue roofs are not actually roof waterproofing systems: they are separate attenuation systems intended to temporarily hold rainwater and slow its discharge, reducing urban flood hazards. Recognising this distinction is critical for good design and integration with modern construction methods.

2.    Separate blue and traditional roofs

A popular misconception is that blue and conventional roofs are the same system. Blue roofs are intended to hold and keep water, whereas standard roofs aim for quick water removal. Separating these systems prevents design compromises and assures compliance with British Standards and Building Regulations. ACO’s blue roof system keeps water away from the roof and off of the waterproofing layer except in extreme cases, meaning the risk of unwanted water ingress is kept to an absolute minimum.

3.    Address key design considerations early

It’s important to address the number, placement, and size of roof outlets, roof fall gradient, kind of roof construction, and time period for water retention of a roof system at the design stage. These elements are required for both the roofing and blue roof attenuation systems to function properly.4.    Mitigate risks with independent systems

Considering blue roofs and traditional roofs as independent systems means any risks associated with design compromises can be mitigated early on. This approach ensures sustainable drainage and prepares for worst-case weather scenarios, enhancing overall building resilience.

5.    Selecting the Right Attenuation System 

The biggest challenge is knowing which attenuation system to select as part of the project. It is recommended that a blue roof attenuation system, that keeps form and function distinct, should be adopted. Systems like ACO’s RoofBloxx, for example, operate independently of the roof waterproofing and drainage system, ensuring compliance with building standards. They also ensure efficient water management during extreme weather events. Given how frequent extreme weather conditions appear to be happening across the UK, this couldn’t be more important.

What’s next? 

Architects and designers have a crucial role to play in the implementation of blue roofs. From ensuring they are designed to meet the regulations, to determining the full environmental benefits when assessing any potential future impacts, architects will be pivotal in integrating these systems into infrastructure.

By following these tips, and working closely with the manufacturers themselves, architects and engineers can effectively de-risk blue roof projects and contribute to sustainable urban development.

To learn more about the Patented  ACO Blue Roof System please click here