BluRoof – The Definition of Stormwater Management

Posted by david.luukas

BluRoof is a roof designed to alleviate flood risk by reducing and controlling the peak rate of discharge in compliance with design requirements; facilitating the detention of stormwater, up to a prescribed maximum hydraulic head, for subsequent discharge over an elongated period of time.

Blue roofs can include open water surfaces but can also be used in buried applications, such as raised deck surfaces or green roofs. Indeed, by combining the Alumasc Blackdown Green Roof with a Harmer BluRoof system, the retention of stormwater in the green roof’s layers (i.e. plants, substrate and drainage/reservoir layer) complements the detention of stormwater by the blue roof to provide valuable additional drainage capacity.

BluRoof Product BreakdownBluRoof – The System

Alumasc is a supplier of high performance roof drainage and waterproofing solutions in the UK. Over the past decade we have seen a marked shift in the performance expectations of modern roofs; requiring watertight, energy efficient envelopes that can attenuate stormwater, recreate local habitat and enhance indoor environmental quality with the most efficient use of resources.

Alumasc’s business strategy has been, and continues to be, well-aligned with these requirements; actively pursuing sustainable building products, systems, manufacturing processes and support services that provide Clients, Developers and Contractors with whole-life value and peace of mind.

BluRoofBrochureButton2_Large2 The Alumasc BluRoof system benefits from the combined expertise associated with Alumasc Roofing Systems and Harmer Engineered Drainage Systems; allowing a truly single source BluRoof solution that is so integral to a system of this nature. The Alumasc BluRoof System comprises of 3 primary facets:

1. The engineered Harmer BluRoof Outlet with Orifice Restriction Device restricts the maximum permissible discharge of stormwater from the roof to predictable levels; accounting for the stage-discharge relationship. As a result, during more intense storm events, rainfall will exceed the rate of discharge, leading stormwater to temporarily back-up on the roof until such time as the Harmer Roof Outlet has the capacity to discharge it.

2. The Alumasc BluRoof Waterproofing; the specification, detailing and installation of which is integral to the success of a BluRoof system – protecting the building against water ingress. There are essentially 2 types of BluRoof; each with 2 typical variants:

bluroof inverted roofa) Inverted Roof

A roof with the insulation situated above the primary waterproofing layer

Podium – surfaced with paving stones on supports

Green roof – typically comprising vegetation, substrate and water management
(or detention, drainage and filtration) layers


b) Warm Roof

bluroof warm roofA roof with insulation immediately below the primary waterproofing layer and above the independent vapour control layer

Open surface – similar to a conventional flat roof; albeit with extended details to accommodate the higher-than-typical depth of water to be managed at roof level

Green roof – typically comprising extensive green roof vegetation, substrate and water management (or detention, drainage and filtration) layers


3. ‘BluRoof – The Alumasc Promise’ – a service package that provides the client, specifier and the end user with complete confidence in the integrity of the waterproofing and drainage solution. Waterproofing solutions for flat roofs and podia are widely specified. However, not all systems are equal and specifying the solution that has the product characteristics that are suited to the specific application is fundamental to delivering long-term value. Equally, flawed workmanship often results in system failures leading to leaks and costly repairs. This is avoidable if installation is carried out correctly and is guaranteed to last.

To address these issues Alumasc has introduced ‘BluRoof – The Alumasc Promise’ – developed exclusively by us to provide the assurances needed to reduce risk and ensure the long-term performance of your roof.

The package includes detailed technical guidance pertaining to the appropriate safety measures that must be in place (e.g. stormwater management calculations, provision of safety overflows, the adoption of a robust planned and preventative maintenance programme etc).

This Promise guarantees the integrity of your roof prior to, during and after installation and is designed to safeguard against the most common pitfalls. It gives you the security of expert installers, continual on-site supervision, expert testing and comprehensive post-installation support.

Click here to find out more about Alumasc Roofing System’s BluRoof.

Free Alumasc Roofing Brochure

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