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Blue Roof System

Roof Level Sustainable Drainage System

BlueRoof logo

A Radmat Blue Roof system is an effective means of providing a Sustainable Drainage solution (SuDS) in inner city and urban environments, in compliance with the requirements of the 2019 draft London Plan.

Storing water above the waterproofing layer a Radmat Geocell Blue roof system provides a method of regulated control to meet a limited discharge consent in accordance with SuDS design principles. Rainwater is held for no more than a 24-hour period from the end of the maximum designed rainfall event, and achieves half empty within a 12-hour period.

Designed to accommodate a 1 in 100-year storm event plus 40% climate change factor using FEH13 (Flood Estimation Handbook) data a Radmat Blue Roof system can be integrated within Radmat new build or refurbishment roofing systems and be incorporated in the Radmat System Warranty.

Radmat’s PermaQuik PQ6100 was the UK’s first waterproofing system BBA Certified for use in Blue Roof applications, enabling the specification of waterproofing, insulation, blue roof and green roof system from a single source.

 

Blue Roof Systems

DESIGN

Radmat Blue Roof systems are designed by our in-house team to achieve the required attenuation volume and/or the required discharge rate, with discharge rates significantly below the greenfield run off rate of 5 litres a second equivalent being achievable.

No special rainwater outlets are required for the Radmat Blue Roof system, our flow control and overflow devices work with any brand of rainwater outlet. We do however recommend the inclusion of a telltale provision as with any temporary or permanent water holding system.

FINISHES

Radmat Blue Roof systems are and suitable for zero falls flat roofs, terraces and podiums. Radmat Blue Roof systems can be finished with paving, 20/40mm ballast or a green roof system and can deliver amenity and rainwater source control.

DESIGN CONSIDERATIONS

When designing a Blue Roof system in addition to advising on the depth of the geocells Radmat will highlight the impact the overall FFL-SSL as the roof thickness will increase, impacting both threshold heights and the height of the waterproofing upstand. A suitably qualified person will need to assess the impact of live load on the roof.

QUICK LINKS

Finishes can be paving on pedestal, bedded paving, 20/40mm rounded ballast or a green roof system such as Radmat MedO system or an Intensive system by others.

Where a support system for ancillaries, air conditioning, air handling equipment etc. is installed directly onto the Geocells, a 1m x 1m spreader plates must be used beneath each foot.

Where bedded paving is used Radmat DM12 must be installed over the Blue Roof system.

Filter sheets prevent the substrates fines clogging the drainage board.

Read more about Blue Roof Filter Sheets here. 

A range of geocells to suit loading and storage requirements.

Read more about Blue Roof Geocells here.

 

The means of controlling the rainwater flow rate from the roof, incorporating overflow capability at H max.

Read more about Blue Roof Flow Control devices here.