Before answering this question, we should first explain what a blue roof actually is.

A blue roof is an evolution of the existing green roof concept with one significant difference. This type of roof has been designed to help store water and in particular, rainfall.

What Are They Used For?

Whilst the goal of standard roofs is to ensure that water drains at the earliest possible stage, a correctly installed blue roof will deliberately retain some or all of the water above the waterproofing membrane. The water can then be deposited through a designated channel, such as a drain outlet to an area that will cause less damage at a later time.

What Are The Risks?

Unlike green roofs which have no major drawbacks, blue roofs do however have a number of associated dangers. These include:

  1. Weight Issues – There is no way to disguise the fact that water is heavy and the build-up of water on a roof can pose structural issues.
  2. Leakage – Blue roofs are installed with a waterproofing membrane but if this becomes damaged and begins to leak, the damage that could be caused by water cascading thorough could be catastrophic.

Can Anything Be Done To Combat These Risks?

We are designing a modular blue roof to help reduce these risks. By ensuring that should any issues arise, only one module rather than the entire roof may need to be replaced, speed and cost issues can be abated.

We can replicate the benefits offered by the M-Tray® with green roofs for blue roofs and by creating a cavity, we can allow the water to easily congregate and be dispersed wherever necessary.

Please Note – Blue roofs are typically only suited to new builds. Unlike green roofs which are particularly well suited to retrofitting thanks to the M-Tray®, this is not advised with blue roofs.

Which Areas Are Suited To Blue Roofs?

There are 4 primary areas where the installation of a blue roof can prove to be beneficial

  1. Storm Water Management– The excess water deposited during storms can play an obvious and significant role in flooding throughout many areas of the world. The installation of a blue roof can play a pivotal role as part of a SUDS (Sustainable Urban Drainage Systems) at roof level. This will help to reduce the impact of rainwater runoff as the flow can be controlled through specifically designed outlets and redirected to less harmful areas. 
  2. Rainwater Storage– With rainwater being precious in many countries, finding a way to store rainwater effectively has taken on greater importance than ever before. The installation of a blue roof to a property can play a key role in the storage of rainwater. The harvested water can also be redistributed for irrigation purposes.
  3. Reduced Energy Costs– Blue roofs are known for their cooling properties and as such, can actually help to reduce the energy bills for the property to which they have been installed.
  4. Cooling and Energy Consumption– There was a study on a cider factory in Frankfurt on the Possman Cider Factory and Storage Facility on a blue roof which was installed in 1990 and this paid for itself in electricity costs for cooling within 3 years. Click here for more on that study.

To find out more about the M-Tray®, please click here to visit the dedicated area of the site or call us at Tel. No. 020 8916 2222.