BMI UK & Ireland has enhanced its portfolio of pitched and flat roofing technology solutions with new Green and Blue Active Roof Systems.
Active Roof Systems is how BMI UK & Ireland describes roof coverings that perform a greater function beyond shelter and protection. While weather-tightness is the primary purpose of a roof, with the right technologies, roofs can be transformed into power stations, rainwater recycling systems, or an opportunity to reduce energy costs.
The new systems offer contractors inherent design and product quality, ease of installation, great configuration options and technical support – all at highly competitive prices.
BMI Canopia Green Roof
An evolution of BMI’s existing offer, the BMI Canopia Green Roof offers the chance to create natural spaces in the sky, improving air quality, biodiversity and well-being for building users. Whether designed to be walked on, to provide a roof-top garden, or simply to improve the aesthetic of the building, Green Roofs can reduce storm water run-off and can improve overall building performance by protecting roof surfaces from extreme weather.
BMI Canopia also improves the thermal efficiency of buildings by providing an additional insulatory layer, while reducing solar gain and the effect of ‘urban heat islands’, which can be damaging to both health and the environment.
BMI Canopia is a range of four standard systems – Sedum, Wildflower, Biodiverse and Intensive Green – and the product and planting options available combine to deliver a huge number of roof permutations. The company is also eager to work with contractors to develop bespoke solutions for customers.
Sedum roofs lend themselves to rainwater attenuation, owing to the succulent nature of the planting; Wildflower and Biodiverse roofs deliver meadow habitats to support a greater breadth of flora and fauna than Sedum types; while Intensive Green Roofs are designed to be trafficked, creating gardens and recreational spaces for sport and leisure.
BMI Blue Roof
BMI UK & Ireland is also launching its new Blue Roof system. Blue Roof systems control water flow from rooftops and limit flooding during heavy rainfall. A water attenuation board, which stores water temporarily, is covered with a permeable top layer, which itself can be a Green Roof to further increase roof attenuation capabilities, while outlets work to restrict the flow rate of water from the roof to greenfield levels.
Blue Roofs can be deployed in inverted roof structures, podium decks, warm roofs and ballasted roofs. The build-up of an inverted Blue Roof, for instance, would comprise a waterproofing layer, insulation, water attenuation void former, filter layer and the top, permeable, layer.
Blue Roofs tend to require fewer outlets than a traditional design, which means that construction times can be shorter and there are fewer penetrations to reduce the risks of faults or leaks. The number of flow restrictor outlets, the openings within that outlet and their position must be carefully designed and installed accordingly. An important step in the installation process is a post-installation inspection to ensure the roof has been built to the intended design.
BMI Blue Roofs comply fully with the National Federation of Roofing Contractors’ (NFRC) Blue Roof design guidelines. The NFRC guide says that the roof should hold water for no longer than 24 hours and the flow rate should be such that half of the roof’s capacity is discharged after 12 hours.
Blue Roofs should be equipped with an emergency overflow outlet to allow excess water to be discharged should there be an unusually high rainfall, that is a 1:100 storm event. In BMI’s system, the overflow is set into the middle of the main outlet, with a vertical pipe cut at a height to match maximum water levels.
Blue Roofs are gaining popularity in the UK as an alternative form of sustainable urban drainage system (SUDS). Other methods such as below-ground water attenuation tanks can be more expensive to construct and may not be possible in built-up areas.
Where technical assistance is needed, contractors can benefit from BMI’s complete six-step ‘cradle to grave’ design, advice and calculation service. This begins with consultation and site surveys, leading to specification, site support and project monitoring; and concludes with industry-leading roof systems guarantees for both roof types. On completion, the roof is covered – both literally and metaphorically.
BMI UK & Ireland also has a dedicated field service network of technical advisers available to work as part of the contractor’s team on bespoke Green or Blue Roof specifications to meet any specific project requirements. This service is free of charge and its consultants are available at any time to answer queries on any aspect of Green or Blue Roofing design.