March 2021

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York Region Administrative Centre Annex, Newmarket, ON. Stormwater Management Roof System from ZinCo Canada Inc. Crocs, Inc. Headquarters, Broomfield, CO. Mountain Equipment Co-op, Toronto, ON. M A R C H 2 0 2 1 | 21 Green Roofs & Walls P H OTO G R A P H Y CO U RT E SY N ED L AW L I V I N G WA L L S; ZI N CO C A N A DA I N C .; GS K Y P L A N T SYS T EM S , I N C .; S O P R EM A super lightweight systems, XF301. The system uses four core layers: the pre-vegetated Sedum Blanket, Retention Fleece, Drainage Mat, and Root Barrier. "We set up a 1.8-metre by 1.8-metre vegetated roof assembly and a wind machine generated 200km per hour winds. The system was shown to withstand the force," says Liu. Another system that passed 200 km/h wind was the StormCap+Detention. It offers increased stormwa- ter retention as well as detention, which Liu explains is receiving increasing attention in recent years. While retention has gained more exposure of late and defines the water that never becomes runoff due to evaporation and transpiration, detention in con- trast deals with slowing down the remaining volume that cannot be taken care of by using retention alone. Liu says an increasing focus is being placed on detention, especially during heavy rainstorm events, where runoff from roadways and rooftops tend to overwhelm the sewer system leading to flash floods. "The system has a detention component so it delays the outflow of the runoff and doesn't put increased stress on an already overburdened and aging drainage system. This is great for the environ- ment as combined sewer overflows are prevented." Jelle Vonk, business manager at ZinCo Canada Inc. is also seeing increasing interest in stormwater management roofs. "Our Stormwater Management Roof can well support cities' goals, as it is designed to reduce the amount of water coming from the roof in a predictable and reliable way, and can be adapted to local conditions and rain events. It focuses on a combination of controlled runoff, short-term accu- mulation under the green roof assembly, and to some extent also slower runoff through the growing medium [runoff coefficient]," Vonk explains. By adjusting the runoff limiter and the depth of the short-term accumulation under the green roof build up, Vonk's team can precisely determine and adjust the runoff from the roof and the time in which the retention volume is available again. Another area gaining traction is urban farm roofs resulting from a growing consciousness about the benefits of locally-grown food. "Rooftops are quickly becoming favoured places to grow vegeta- bles and give people an opportunity to exercise their green thumbs," explains Vonk. ZinCo has developed the Urban Farming Assembly as a perfect solution to grow fruits and vegetables on the roof. The drainage element, Floradrain FD40-E, and a special blended growing medium are at the heart of this assembly. "Schools, grocery stores, and restaurants for exam- ple are growing produce, which they sell or use in their own businesses or they are growing for local clients and food banks." One ZinCo project that showcases the benefits of urban rooftop farming is Avling Brewery in Toronto's east end – the first purpose-built green roof for food production in Toronto. The owners use produce from their own ZinCo rooftop garden to supply the res- taurant below. Due to its success, it's owner, Max Meighan, is now looking for a second site where he can incorporate a green roof that would integrate a heat recovery system and aquaponics. One of the most common questions raised about green roofs, still, is their longevity, and when it comes to that question, Soprema has the answer! Back in 1998, Soprema was tasked with the installation of the Sopranature green roof on the Mountain Equipment Co-op building in Toronto – a system consisting of a mix of seeding (85 percent) and planting (15 percent) specifically designed to protect the waterproofing system from all potential physical and thermal damage. In 2019, 21 years later, Soprema was able to gain access to the roof and per- form a cut test on two different parts ahead of the building being demolished. The testing of the samples was then done to assess how the bitumen and different compo- nents of the waterproofing system have evolved and degraded over time. And the result? It was clear that the green roof protected the waterproofing system, as the SBS poly- mers were almost as good as new. While it is not possible to give a precise estimate on the extended life expectancy of the waterproofing system, to say that it doubles seems to be a very timid assumption after 22 years of service. The covered sample was almost exactly the same as a new SBS-modified bitu- men membrane. "What we can take from this testing is that a green roof does indeed protect the waterproof- ing system and that the MEC sampling proves it. This green roof also helped pave the way for many more installations, standardizing the green roof in the building envelope design as well as helping in the adoption of the Toronto Green Roof Bylaw," says Roxanne Miller, landscape architect at Sopranature. Exciting developments are being seen over at GSky Plant Systems, Inc., a global industry leader in the design and production of interior and exte- rior green walls. In 2020 the company installed a 900-square-foot Indoor Living Wall at the Crocs, Inc. new headquarters in Broomfield, Colorado. Crocs wanted a space that would put employees' needs front and centre by maximizing employee health and well-being. As part of that commitment they approached GSky whose living walls are irri- gated by low flow drip emitters on programmable controllers and in many cases can be equipped with recycling components to create an extremely effi- cient low water usage system. The living wall is flush with both native and non- native plant species, bringing the outside in, adding a sense of fresh air, life, and texture to the workspace. And when it comes to green walls, one com- pany in particular is leading the way. Nedlaw Living Walls' Adam Holder, sales and marketing manager, says that contrary to expectations, business ramped up during the pandemic in 2020 and attributes a growing awareness to the importance of indoor air quality. "Most of our work is for institutional buildings, but we saw a greater number of enquiries from own- ers of smaller scale commercial and residential condos. Bank buildings are also starting to identify the need for a focus on sustainable architecture and to explore ways to improve indoor air quality." Last year, however, didn't come without some disappointments, one of which was the dismantling of a stunning living wall biofilter that encompassed about 2,400 square feet in the entrance atrium of the Edmonton Federal Building. "We had completed that in 2014 and this biofilter was integrated into the building's HVAC system to improve indoor air qual- ity, regulate humidity, and reduce the building's environmental impact. It was removed as a cost saving measure, but in my opinion and that of its designers, constructers, and caretakers, the benefits it provided for the building, the city, and province far exceeded the expense." On a more positive note, Nedlaw recently com- pleted the world's tallest living wall biofilter at 83-feet high at the York Region Administrative Centre Annex (ACA), which will clean approxi- mately 16,000 cubic feet of air per minute (CFM). There are also some exciting new developments coming ahead for Nedlaw Living Walls, which Holder says are currently under wraps! For now, Holder is continuing to explore other creative appli- cations for living wall biofilters and helping to educate the public on their many benefits. A

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