December 2019, vol. 61, no. 9
www.constructioncanada.net
The Official Publication of Construction Specifications Canada
La publication officielle de Devis de Construction Canada
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Corinne Golding Specifications Inc.
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DGS Consulting Services Ltd.
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On the Cover
For the three-storey Whistler Community Services Society (WCSS) building in British Columbia, AKA architecture + design used different types of engineered wood to create as simple a structure as possible with vertical cross-laminated timber (CLT) panels, a glue-laminated (glulam) post-and-beam interior frame, CLT ground and upper floors, and a glulam and CLT roof.

Photo © Andrew Doran Photography. 
Photo courtesy AKA architecture + design

See article on page 8.
Features
 8		Employing Wood in Commercial Buildings

The 2015 edition of the National Building Code of Canada (NBC) permits mixed-type occupancies on the first two storeys of wood buildings. Two facilities in British Columbia, both with primary retail occupancies, employ several mass wood products to achieve very different effects.

20		Door Trends for Critical Environments

Although high-speed doors are not new, many of their applications are, along with the regulatory standards that apply to them. As such, choosing an appropriate model is more complex, and important, than ever for cold storage facilities.

28		Self-drying Flat Roofs

Roof enclosures have the largest litigation potential in the construction industry due to complexities in design, application, and environmental exposure. A self-drying roof enclosure would minimize the litigation potential and provide additional benefits, such as increased roof resiliency, reduced financial burden, and minimal impact on the environment.

34		Detrimental Effects of UV on WRBs

Water-resistive barriers (WRBs) play a vital role in the performance of a wall system. Unfortunately, barriers can be undermined even before they clad the walls due to ultraviolet (UV) exposure. Understanding and minimizing the impact of UV on WRB is critical to ensuring the integrity of the wall assembly and building performance for years.

46		Standardizing Power-operated Doors

Power-operated doors come in a variety of designs and styles to fulfil the functions of the building envelop and interiors. Among the considerations are reliability, safe egress, accessibility, energy conservations, security, and esthetics.

50		Emerging Leader Awards: Meet the finalists
Earlier this year, Construction Canada launched the Emerging Leader Awards program, presented by Engineered Assemblies. The awards honour members of the architectural, engineering, and construction (AEC) community who demonstrate excellence, inspire their co-workers, and are well on their way to becoming the next leaders in the profession.
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On the Web
Hariri Pontarini wins $100k international RAIC prize
Designed by Toronto-based Hariri Pontarini Architects, the Baha’i Temple of South America in Santiago, Chile, has won the coveted 2019 Royal Architectural Institute of Canada (RAIC) International Prize.
The temple’s nine torqued wings, bound to an oculus at the top, are made of an outer layer of cast-glass panels and an interior layer of translucent marble from Portugal. The invention of this new material—cast-glass cladding—took four years of experimentation and collaboration with a Canadian glass artisan.
The interior spaces of the temple are designed to invite people to come together and sit in quiet contemplation. An alcoved mezzanine offers a space to seek solitude while remaining connected with the community below.
www.constructioncanada.net/hariri-pontarini-wins-100k-international-raic-prize

B+H Architects restore historical Toronto building
Award-winning consulting and design solutions firm B+H Architects (B+H) has signed a lease with Menkes Developments and TD Greystone Asset Management for 2138 m2 (23,008 sf) of office space at a heritage building in Toronto.
The building on 320 Bay Street was designed by prominent Canadian architect Henry Sproatt and originated as the Canada Permanent Trust Building.
The 27,871-m2 (300,000-sf) building is undergoing a major restoration, which will improve the quality and service of the space.
B+H will be providing design direction for key public spaces, preserving the building’s historical architectural elements while balancing them with new, modern amenities for future tenants. The revitalization also includes an updated lobby façade entrance and electrical and mechanical upgrades.
www.constructioncanada.net/historical-toronto-building-is-bh-architects-new-home

The vase-like form of CITIC Tower
Designed by KPF, the 528-m (1732-ft) CITIC Tower is Beijing’s tallest building, and the eighth tallest worldwide.
CITIC Tower’s design draws inspiration from the ‘zun,’ a ritual vessel originating in Bronze Age China. In profile, the tower abstracts and refines the zun’s vase-like form, balancing composition and articulation with structural requirements and leasing depth needs. In plan, the building is square with rounded corners; its width transforms vertically from its 78-m (256-ft) wide base to its 54-m (177-ft) wide ‘waist’ and then its 69-m (226-ft) wide top. Broader at its base than its crown, the tower combines its iconography with infrastructure that supports the building’s integrity in China’s greatest seismic zone.
www.constructioncanada.net/the-vase-like-form-of-citic-tower 
Calendar 

January 16−19
Interior Design Show
Informa
Toronto, Ontario
Metro Toronto Convention Centre
www.interiordesignshow.com

January 27−30
The International Surface Event (TISE)
Informa
Las Vegas, Nevada
Mandalay Bay Convention Center
www.intlsurfaceevent.com

February 3−7, 2020
World of Concrete
Informa
Las Vegas, Nevada
Las Vegas Convention Center
www.worldofconcrete.com

February 4–6, 2020
International Roofing Expo
NRCA/Informa
Dallas, Texas
Kay Bailey Hutchison Convention Center
www.theroofingexpo.com

February 11–14, 2020
Sprayfoam Convention & Expo
Spray Polyurethane Foam Alliance
Pasadena, California
Pasadena Convention Center
www.sprayfoam.org/expo

February 26, 2020
CSC Building Expo
CSC Toronto Chapter
Toronto
Metro Toronto Convention Centre
www.cscbuildingexpo.com

May 20–24, 2020
CSC National Conference
Construction Specifications Canada
Montréal
Hôtel Bonaventure Montréal
www.csc-dcc.ca/conferences 
Photo © Doublespace Photography

Hariri Pontarini Architects has won the 2019 Royal Architectural Institute of Canada (RAIC) International Prize for the Baha’i Temple of South America in Chile.
COVER Story
Photo © Florian Maurer. Photos courtesy Allen + Maurer Architects Ltd.

Employing Wood in 
Commercial Buildings
By Jim Taggart, FRAIC

I
n 2009, the British Columbia Building Code (BCBC) was amended to permit residential buildings of up to six storeys to be constructed in wood. Since then, through a continuous process of consultation and research, the potential for expanding these provisions to other building occupancies has been under consideration at the national level.
Changes introduced in the 2015 edition of the National Building Code of Canada (NBC)—when it is adopted by the provinces—will expand these provisions to office-type buildings, but also permit mixed-type occupancies on the first two storeys. As a result, wood buildings may now include office, residential, mercantile, assembly, low-hazard, or storage/garage-type uses. As of 2018, such buildings have been permissible under BCBC.
This article examines two wood buildings, both with primary retail, commercial occupancies, but employ different mass wood products to achieve varied effects. A more in-depth look at these projects can be found in a new case study released by the Canadian Wood Council/Wood WORKS! BC.1

Askew’s Uptown Supermarket
Located in Salmon Arm, B.C., a city of about 20,000 residents midway between Vancouver and Calgary, Askew’s Uptown Supermarket is the first phase in a new mixed-use development that is destined to become the commercial heart of a fast-growing residential neighbourhood.
The high side of the sloping site borders a frontage road paralleling the Trans-Canada Highway. This slope presented challenges in establishing suitable grades for buildings with large floor plates and for engineering conventional approaches to vehicular access. In response, Allen+Maurer Architects (who also created the master plan for the site) inverted the usual suburban supermarket arrangement. Instead of a box surrounded by parking, they pushed the 3000-m2 (32,291-sf) building to the edge of the site, tucking it into the slope. As future phases are completed, they will frame a village square at the centre of the site.
The supermarket’s design responds to priorities of the client, the needs and aspirations of the community, and the materials and construction expertise available in the region. The forest products industry has been a traditional mainstay of the local economy, although it has recently experienced a decline. With family roots in the forest industry, architect Chris Allen saw this project as an opportunity to fight back. Similarly, as a service provider to that industry for several generations, Askew’s Foods wanted to make its project a statement of community support by maximizing the use of local wood products and labour.
The resulting building is both simple and elegant—a radial plan generated from the centrepoint of the future town square, slender concrete and steel tree columns for maximum flexibility, a fully glazed front façade, and a vast ‘floating’ wood roof was constructed using nail-laminated box beam elements prefabricated from locally sourced wood.
With a design snow load of 0.5 psi (3.5 kPa), a traditional wood roof for a building of this scale would have consisted of glue-laminated (glulam) beams and purlins with heavy timber decking above. Such a roof would have required considerable depth, and the lattice of heavy timber members would not have achieved the floating effect desired by the architects. Additionally, for consistency of appearance, the tapering structural bays would have required glulam beams of equal depth, despite variations in span from 5 to 10 m (16 to 31 ft).
Instead, for economy, efficiency, and improved esthetics, structural engineers Fast + Epp designed the 3000-m2 roof of the building as a series of 1200-mm (47-in.) wide nail-laminated timber (NLT) box panels, supported on a primary structure of steel beams. These beams rest on tubular steel branches that spring diagonally from cylindrical concrete columns as noted above. Lateral resistance in the vertical plane is provided by steel cross-bracing along the south wall, long shear walls on the east and west sides, and two short sections of shear wall on the north side of the building.
The NLT box beams have a consistent depth and continuous soffit treatment, but with variable joist spacing according to the length of span. The joists are regular 2x12 sections, used singly or doubled up for panels spanning up to 7 m (24 ft)—the longest available section. For the 10-m spans, 7 and 2-m (8-ft) sections were overlapped longitudinally and nailed together face-to-face in pairs to form beams. All the panels were finished with one layer of 13-mm (1/2-in.) plywood sheathing on top, while the spaces between the joists were filled with alternating 2x4 and 2x6 members at the bottom.
A 300-mm (12-in.) gap was left between panels to conceal sprinkler lines. These gaps are bridged by plywood on top and have corrugated cover panels beneath made from vertically staggered 2x3 members to match the main panel soffits. The panels use a total of 580 m3 (20,483 cf) of locally harvested dimension lumber and 1320 sheets of plywood.
The lumber was sourced from five regional mills to meet the demands of the schedule and to allow for competitive pricing. Shop prefabrication of the wood components also enabled the work to be carried out over the winter, providing off-season employment for carpentry crews. The simplicity of the design meant special tools or skills were not required.
The finished panels were hoisted onto the steel beams in the summer; there was no need for painting or electrical work. Sprinkler installers were able to kneel on the roof to drop the pipes in the provided slots, rather than working above their heads from scaffolding in the building. A second layer of 13-mm plywood was installed in the field to create a roof diaphragm.
The panels did not contain insulation. Instead, continuous rigid insulation was laid on top of the field-installed plywood sheathing before the roofing membrane was applied. The vapour retarder is also located on top of the plywood sheathing. The maximum volume of the voids within the panels is less than the threshold for sprinklering of concealed spaces.
Since the lumber used has simply been cut from raw logs and not undergone any further processing, it has very low embodied energy and the benefits of natural carbon sequestration and storage within the wood fibre are maximized. It is estimated the roof structure contains 546 metric tonnes of embodied carbon. In addition to the tangible benefits of low-carbon construction and local employment, the form, materials, and organization of the building express the unique qualities of the site, and enhance the role the building plays as a social hub for the community of Salmon Arm.
Doubling as a retaining structure, the south wall of the building reconciles the change in level between the street and the future urban square below. The sweeping roof with its exposed Douglas fir soffit creates a warm ambience while the expansive windows admit abundant daylight and offer views of the surrounding mountains. The projecting eave soffit is protected by a flashing on its leading edge.
Perhaps appropriately for a grocery store, the design of Askew’s, in some respects, parallels the ambitions of the slow food movement. Just as slow food has promoted the virtues of quality and taste over the agri-business model of uniformity and convenience, the design of Askew’s puts the ecological, economic, and cultural sustainability of the community first.

Whistler Community Services Society building 
The Whistler Community Services Society (WCSS) is a nonprofit providing a variety of social services to the residents of the Resort Municipality of Whistler, B.C. WCSS operates a food bank and a range of social and community programs, partially funded by a ‘Re-use It Centre’ that sells second-hand sports equipment and other donated items.
Rapid expansion of its retail operations and community services resulted in WCSS programs being spread across multiple locations, thus increasing operational inefficiencies and overheads.
With the complexities of a mixed-use program, including high-clearance storage areas and retail and office spaces, together with a desire to be close to the town centre and accessible by transit as well as private vehicles, WCSS concluded the best option for consolidating its operations was to construct a new building on a vacant site in the municipal works yard.
Due to the heavily trafficked, industrial nature of the site, the WCSS board decided the building should be constructed by using the traditional combination of a steel frame structure, with tilt-up concrete (structural insulated) panels for the exterior walls. AKA architecture + design headed the project’s design team and Fromme Engineering was the structural engineers.
The project went through the schematic design and design development phases, received both development and building permits, and was put out to tender as a construction management contract based on this steel and concrete structural system. However, it soon became apparent the concrete structural insulated panels (SIP) supplier was unable to meet the required construction schedule.
Whistler has long, cold winters with significant snowfall, restricting the construction season for concrete work in particular to the six months from May to October. Faced with this untenable situation, the WCSS board instructed the design team to investigate the feasibility of a mass wood alternative.
AKA architecture + design brought in a cross-laminated timber (CLT) fabricator (Penticton, B.C.) who recommended Fast + Epp design the wood structure. The first priority was to determine whether a wood alternative could be designed and delivered within the client’s tight time and cost constraints. From a cost perspective, the design team had a known tender price for the steel and concrete building as a benchmark.
In the end, the two solutions were almost identical in cost. Poor soil conditions meant large foundations were required for the concrete structure, and these could be substantially reduced for the lighter wood option. Since the CLT exterior wall panels could be loadbearing, it was possible to eliminate the perimeter columns required in the steel and concrete option. Additionally, interior finishes could also be removed in some places, as the CLT panels could be left exposed.
The mass wood structure is as simple as possible, with vertical CLT panels, a glulam post-and-beam interior frame, CLT ground and upper floors, and a glulam and CLT roof. The floor-to-floor heights had to be increased slightly, as services designed to run through open web steel joists now had to be suspended below the glulam beams.
The CLT panels were exposed in the counselling rooms and in the storage areas, where racks could be secured directly to the walls. For this project, the client was happy to specify a less expensive industrial grade of CLT, rather than an architectural ‘appearance’ one, and to leave building services exposed.
With only three months between the award of the contract to the required start date onsite, speed was of the essence. According to Carla Dickof, senior technical specialist at Fast + Epp, “The dimensions of the building as originally designed made it perfect for CLT.”
Both the height and width were just short of 12 m (39 ft)—the maximum length of a CLT panel that is currently available. It also happened to be the maximum permitted height of the building given the pre-existing development permit. The five-ply CLT wall panels were aligned vertically, running the full height of the building from grade beam to eaves, as in balloon frame construction. The elevator and stair shafts were constructed in the same way. This meant the panels could be lifted off the delivery truck and dropped directly into place by Seagate, the mass wood subcontractor. The wood at the elevator and stair shafts were also fireproofed with fire-resistant drywall.
The exterior wall panels had dimension lumber ledgers pre-installed to provide bearing for the five-ply CLT upper floor panels. At mid-span, the floor panels bear on a pair of glulam beams running either side of a central line of glulam columns.
The lateral system uses the exterior walls along the 34-m (112-ft) length of the building, with the panels connected by plywood strips nailed across the joints. For these tall panels to contribute to the lateral system, a creative interpretation of the Canadian Standards Association (CSA) 086-14, Engineering design in wood, was required.2 Across the width of the building, elevator, and stair shafts contribute to lateral stability.
For lateral load distribution, a simple envelope approach was used, considering both rigid and flexible diaphragms. Diaphragm action was achieved by ‘stitching’ the floor and roof panels together using strips of plywood to bridge the seams—the same detail as used for the exterior walls. The revised foundation design is a raft slab, with short perimeter walls to create a crawl space. These concrete walls support both the CLT floors and exterior walls.
The building program is arranged on three levels. The first (ground) level is largely devoted to the sale of second-hand items, with receiving, storage, and sales areas, and seasonal storage is located on the second level (mezzanine) above. The food bank, counselling, and other community support programs operate out of offices and meeting rooms on the third level.
Since the mezzanine occupies more than 40 per cent of the floor area in which it is located, it is not considered a mezzanine, as defined in BCBC. Therefore, the structure is deemed to be three storeys in height. In the specific case of WCSS, the higher hazard retail-use had to be located only 1.5 m (5 ft) from the north property line. Vancouver-based engineering firm GHL Consulting devised an alternative solution that permitted the use of CLT within the exterior wall assembly in the locations where a two-hour noncombustible wall assembly was prescribed by the building code (see “Firewall Alternative Solution,” page 12). Had the mezzanine conformed to the BCBC definition, the building would been subject to less stringent fire performance requirements.
This is the first retail building of its type in Canada. It demonstrates the potential of mass wood construction to compete in this market sector, with comparable costs and enhanced environmental performance relative to ‘traditional’ steel and concrete construction. The wood solution is, in the author’s opinion, cost competitive and highly repeatable. 

Notes
1 Visit wood-works.ca/bc/case-studies-videos.
2 Canadian Standards Association (CSA) 086-14, Engineering design in wood, requires the aspect ratio and platform-framed approach when using the noted ductility values. However, it does provide an alternative approach with lower ductility if the criteria (such as aspect ratios, sliding of panels governing, etc.) are not met. This is a very conservative approach but does offer a path forward for alternate approaches to cross-laminated timber (CLT) structures (such 
as ‘balloon’ style construction) within the current code limitations.
Photo © Martin Knowles
At Askew’s Uptown Supermarket in Salmon Arm, B.C., slender concrete and steel tree columns are used for maximum flexibility. 
Photo © Chris Allen
Askew’s Uptown Supermarket features a nail-laminated timber (NLT) roof.
Firewall Alternative Solution

Floor plan of the store shows tapering structural bays.
For the three-storey structure of the Whistler Community Services Society (WCSS) in Whistler, B.C., Vancouver-based engineering firm GHL Consultants provided an alternative solution to address the exterior wall construction due to the proximity of the building to the property line, which is as little as 1.5 m (5 ft) in some places.
Given the higher fire load for the retail occupancy and the size of the fire compartment in this location, the British Columbia Building Code (BCBC) 2012 prescribes no more than 10 per cent of the wall adjacent to the property line be unrated window openings and/or wall area. The remaining (minimum 90 per cent) of the wall assembly must have a two-hour fire-resistance rating and be of noncombustible construction.
The functional objective of this requirement is to limit the risk of a fire in the WCSS building spreading to the neighbouring property before emergency responders could perform their duties (e.g. fire suppression and wetting of nearby structures). This could be due to the fire spreading to the adjacent property through a window opening or unrated wall assembly or through ignition of the wall itself.
The alternative solution permitted the use of cross-laminated timber (CLT) within the exterior wall assembly in the locations where a two-hour noncombustible wall assembly was prescribed by the building code. The solution demonstrated a non-loadbearing CLT wall could achieve the required level of performance. This was achieved using a char analysis and specifying mineral fibre insulation and a noncombustible cladding on the exterior side of the CLT. Similar measures could be used on future projects to address the same situation, if reorganizing the program or increasing the distance from the property line were not viable options. 
Architectural section at the south wall showing roof construction.
Photo courtesy Fast + Epp
The cross-laminated timber (CLT) wall panels of the Whistler Community Services Society (WCSS) building in B.C., together with the elevator and stair cores, run from grade beam to eaves, as in balloon frame construction. The panels were lifted off the truck and lowered directly into place.
Photo © Andrew Doran Photography. 
Photo courtesy AKA architecture + design
At mid-span, the CLT floor panels bear on a pair of glue-laminated (glulam) timber beams supported by a central line of glulam columns.
Photo © Derek Lepper Photography. 
Photo courtesy Allen+Maurer Architects Ltd.
View of the tubular steel tree column in Askew's Uptown Supermarket.
Photo © Andrew Doran Photography. 
Photo courtesy AKA architecture + design
Interior of the finished WCSS building showing exposed CLT panels.
Jim Taggart is a Vancouver-based journalist who has written on the subject of contemporary architecture in wood for over 20 years. His credits include more than 100 articles for national and international magazines, numerous technical case studies for wood industry organizations, and the books Toward a Culture of Wood Architecture (2011) and Tall Wood Buildings: Design, Construction and Performance (with Michael Green, 2017). He can be reached via e-mail
at architext@telus.net.
FEature Story
Going 
High Speed
Door trends and industrial curtain walls in critical environments
All photos courtesy Rite-Hite
By Jon Schumacher
A
lthough high-speed doors are not new, many of their applications are, along with the regulatory standards that apply to them. As such, choosing an appropriate model is more complex, and important, than ever.
For example, cleanroom doors are not just used in pharmaceutical facilities anymore—they are prevalent in a wide array of industries. Similarly, cold-storage doors have expanded beyond food processing plants, and are no longer evaluated solely on their insulating and cleanability characteristics (although their relevance to the food industry has only increased with the new U.S. Food and Drug Administration [FDA] standards, which are commonly referenced in Canada). In fact, according to the Canadian Food Inspection Agency (CFIA) and its Safe Food for Canadians Regulations (SFCR), which have been effective since January 15, 2019, doors should also be impervious to moisture, non-absorbent, resistant to deterioration, smooth, and durable. By following these guidelines, as outlined in sections 57 to 71 of SFCR, cold storage doors can help prevent a variety of hazards that would otherwise contaminate food.1
Choosing the right door for a specific application can not only increase efficiencies, but also help ensure regulatory compliance.

Door types
The Door and Access Systems Manufacturing Association (DASMA) classifies a door as high-speed if it moves faster than 508 mm (20 in.) per second. It is a high-performance door if it opens and closes 100 times or more a day (also known as cycles). The most common high-speed door rolls upward into a housing frame known as a header when open. Bi-parting doors have two panels meeting in the middle of a door frame when closed. Strip curtains are sometimes used as an alternative option in food facilities in an attempt to slow heat transfer while simultaneously allowing quick access between rooms.

Cold storage trends
Cold storage facilities are an essential part of the food, beverage, pharmaceutical, and electronics manufacturing industries, among others.
Inside a food storage warehouse, doors serve as a literal gateway between different temperature zones and varying levels of clean areas. It is important these doors meet industry standards such as the National Building Code of Canada (NBC) requirements for door design, fit, marking, and performance.
When it comes to cold storage, there is a trend for bi-parting doors that combine the temperature separation of a high RSI-value and the quick cycle times of a high-speed door. This is especially true for facilities with high ceilings and tall door openings, as bi-parting doors offer openings from floor to ceiling at the same rate.
High-speed, roll-up fabric doors are also gaining popularity in cold storage facilities. In addition to food, they are suitable for keeping pharma products at the temperature levels mandated by government regulations like the Canada Food and Drugs Act. This awareness shift is taking place globally, with the International Energy Conservation Code (IECC) recognizing the importance of high-speed doors, along with the North American Fenestration Standard (NAFS), particularly NAFS-08, Canada’s standard for doors, and the National Energy Code of Canada for Buildings (NECB). In fact, IECC’s 2015 edition includes a revision to Table C402.4.3, which describes the maximum air infiltration rates for fenestration assemblies. As a draft copy of the table notes, their fast cycle times (up to 2.5 m [8 ft] per second) minimizes air exchange, which is a key part of reducing overall energy losses through a door opening.2
Many types of cold storage doors are used in the food industry. While there is no specific ‘cold chain’ requirement in SFCR, it is paramount facilities and equipment within them have the capability to ensure food is kept safe. Frequently, the cold chain is a key component to this supply chain. However, not all doors in food facilities are designed strictly with the cold chain in mind.

Food sector trends
Regulations in the food industry are perhaps more stringent than any industry outside of pharmaceuticals and medicine. Above all, they depend on cleanliness to ensure food products are safe for consumers.
One area that has seen a massive boom in recent years is the ready-to-eat (RTE) food category. This includes precooked meats, cheeses, canned good, bakery, and shelf-stable fare. The Refrigerated & Frozen Foods publication expects the RTE food market to increase more than seven per cent from 2016 to 2026 to an estimated value of nearly $200 billion.3
Clean areas and facility sanitation have been greatly affected by the RTE industry. To follow SFCR, food businesses must develop, implement, and maintain a written preventive control plan (PCP). The PCP helps businesses either reduce food hazards to acceptable levels, or (preferably) prevent and eliminate any potential hazards altogether.
As food facilities must adhere to a cleaner standard, it is essential to find wall and door products that comply with these regulations. New food industry-specific high-speed doors meet a host of North American regulations when it comes to keeping food safe, including SFCR, the United States Department of Agriculture (USDA), and FDA standards for cleaning and sanitation. They are made of smooth polypropylene, which provides a strong resistance to acids and bases and a low water absorption rate, making them highly resistant to mould and providing superior washdown durability. Other food-specific enhancements include: 
• 
washdown-rated sealed drive systems and controls; 
• 
one-piece, ultra-high-molecular-weight polyethylene (UHMW) plastic radial headers, which is where the fabric door is stored when in the open position; and
• 
corrosion-resistant polycarbonate and UHMW side frames, which stand off from the wall to minimize surface-to-surface contact, and reduce pockets where bacteria can grow.

Industrial curtain walls
Much like how high-speed doors are becoming more prevalent in the food industry to separate temperatures and processes within a plant, curtain walls are increasingly being used for clean applications related to blending, mixing, and powder and raw ingredients, or other production operations. One of the most common uses for industrial curtain walls in the food and beverage industry is for the isolation of production lines so one can be cleaned while others continue to run at peak efficiency. These flexible fabric walls not only allow plant engineers to easily enclose areas and contain overspray from cleaning, but also help reduce the potential for cross-contamination during production processes.
Leading washdown curtain walls are constructed of durable, cleanable, anti-microbial vinyl fabric specifically designed for use in operations where compliance with federal food regulations is required. To eliminate the potential for harbourage concerns that can arise with sewn-together or velcro-locked panels, it is important to look for curtain walls using manufactured panels with heat-welded or radio frequency (RF)-welded seams and with air- and water-tight panel-to-panel connections.
Washdown curtain walls are typically suspended from existing ceiling structures or roof decks. Stainless steel components and hardware allow the walls to withstand the wet and harsh conditions occurring when production equipment is cleaned as part of best practices protocol. The protocol, considered a management system, ensures food safety is addressed, as biological, chemical, and physical hazards are analyzed and controlled—from the production of raw materials to the consumption of finished products. If the ability to open and close the wall is needed, heavy-duty stainless steel track and trolley systems are available to ensure easy operation, effectively creating a giant bi-parting clean area door.
The food industry is not the only one taking advantage of high-tech doors. Industries using cleanrooms and clean areas, such as pharma 
and medical equipment and alternative energy manufacturers, are using high-speed doors in order to meet current good manufacturing practice (cGMP) and hazard analysis and critical control points (HACCP) guidelines.

Cleanroom trends
Doors in pharmaceutical manufacturing take on a vital role in helping companies achieve and maintain a specified level of cleanliness for a given cleanroom.
Cleanrooms are classified according to the number of particulates in the air with the cleanest allowing for the fewest particulates. Maintaining an air pressure differential between rooms and pushing air from the opening’s cleaner side to the less clean side, is an essential function. Facilities generally incorporate multiple pressure steps within the building’s structure, ranging from 5 to 13 Pa (0.02 to 0.05 w.g.) between rooms, but can be as high as 50 Pa (0.2 w.g.).
High-speed doors are very common in airlock applications as a means to buffer different classes of adjacent clean areas. A door capable of at least 50 Pa in pressure differential is needed to maintain a tight seal and minimize air leakage. Given the requirement to maintain pressure differentials, doors that seal tightly and cycle quickly are essential in pharmaceutical manufacturing facilities.
Besides the pharmaceutical industry, doors in cleanrooms are being used in medical manufacturing and facilities that produce solar power panels. These types of facilities typically follow the design specifications outlined in International Organization for Standardization (ISO) 14644, Airborne Particulate Cleanliness Classes in Cleanrooms and Clean Zones, which regulate airborne particulate cleanliness classes. Minimizing impurities in the air ensures these products are safe and effective once installed.
Naturally, a prerequisite in overall door design is cleanability, since doors must operate in a pristine manufacturing environment. Any high-speed door that is employed in pharmaceutical, medical device, or solar cell manufacturing must also balance the need for productivity with operational safety.
FDA cleanroom standards outline recommendations and requirements for manufacturers of pharmaceuticals and medical devices. The starting point is to look for doors compliant with cGMPs, NECB, and ISO 14644-1, Cleanrooms and associated controlled environments — Part 1: Classification of air cleanliness by particle concentration. 
Key considerations for any door configuration are ease of cleaning and durability. In all cases, these doors must be able to stand up to repeated cleaning with chemical solvents and have a smooth, hard, non-porous surface resistant to microbial and fungal growth. Doors should also have a tapered surface and edges that essentially eliminate harbourage of dust or other contaminants and do not possess sharp angles to minimize harbourage of microbes. Additionally, they should:
• 
be corrosion-resistant (which is often a problem with older door systems);
• 
use stainless steel side frames and shrouds; and
• 
incorporate a lubrication-free design since lubricants can attract particulates.
It is also advisable to avoid doors with exposed fasteners and coils, as they will take longer to clean and could harbour contaminants.
The ability of cleanroom doors to accommodate site-specific needs is another consideration for industrial designers. These could include features such as vision panels, push plates, or other activation devices, as well as magnetic locks and (perhaps most importantly) interlocking systems.

Choosing the right door
Every application has an ideal door to meet industry standards while providing maximum efficiency. It is incumbent for facility managers to understand what regulations they must adhere to and what door solutions will make for the easiest and safest for workers to use.
High-speed doors, both bi-parting and roll-up, are gaining their places among industries depending on cold storage and clean practices. Due to their advanced design allowing for temperature separation and ability to withstand regular cleanings, many high-speed doors on the market can meet mandatory regulations such as SFCR, FDA, and also the HACCP Canada certification program among others, for the food, pharma, and emerging industries. Whether it is meeting cold chain requirements or cleanliness standards, or both, there is a high-speed door that is the right fit for the operation. 

Notes
1 See laws-lois.justice.gc.ca/eng/acts/S-1.1.
2 Read more at www.ecodes.biz/ecodes_support/free_resources/Pennsylvania/PDFs/2015_IECC_Revision_History.pdf. 
3 See www.marketwatch.com/press-release/ready-to-eat-food-market-to-exceed-us-1953-billion-by-2026-2019-10-14.  
Bi-parting doors combining high RSI-values and quick cycle times are becoming increasingly prevalent in cold storage facilities.
The fast cycle times of high-speed, roll-up doors minimize air exchange, thus reducing energy loss through a door opening and saving costs.
Maglio Companies

Photo courtesy Rite-Hite
Wisconsin-based produce processing facility Maglio Companies’ cleanroom and clean-area doors incorporate one-piece, ultra-high-molecular-weight polyethylene (UHMW) radial headers and side frames, which stand off the wall in order to minimize surface-to-surface contact and bacterial growth. 
In Milwaukee, WI, produce processing facility Maglio Companies has been using bi-parting and high-speed, roll-up doors to maintain temperature and humidity levels for a large variety of fruits and vegetables.
After trying mechanical sliding doors with high RSI-values (10 in this case), and then strip curtains for three storage coolers within the loading dock area, the company knew it needed a new solution. If the doors were bumped into by forklifts, the downtime led to moving products from one cooler to another at best and potential spoilage of food at worst. Meanwhile, the strip curtains could not maintain a seal due to positive pressure from inside the coolers blowing them out.
The facility put in a high-speed, roll-up door on one of the coolers as a trial. The setup included a fabric door that rolled up into a header above the door. A motion sensor on the outside of the cooler automatically activated the door on the approach and closed it once the forklift was safely inside. To exit the cooler, a forklift operator would use a pull rope or push button to raise the door.
However, it was quickly determined the door would not be able to meet their needs. The door made from fabric curtain was not flexible enough to handle the cold temperatures. A new door was installed using a more flexible fabric made from smooth polypropylene and aluminum sides that are easily removable for cleaning from a one-piece radial header machined from a solid block of ultra-high-molecular-weight polyethylene (UHMW) plastic. It was successful.
The quick cycle times reduced the likelihood for forklifts to hit them, and increased their efficiency moving through them. Those quick cycles also diminished air infiltration, which stabilized the environment and reduced energy use. The fabric of the doors proved to be effective in minimizing conduction between different temperature and humidity zones.
Before the high-speed doors were implemented, the compressors were running constantly to keep the environment cold. After installing the doors, the compressors would cycle off frequently, saving energy and costs. 
High-speed doors, like this one at Maglio Companies, a produce processing facility in Milwaukee, WI, minimize collisions with forklifts.
Jon Schumacher is the director of marketing for Rite-Hite Doors. He has been with the company for 20 years and is the vice-chairman of the Door and Access Systems Manufacturers Association (DASMA). Schumacher can be reached via email at jschumacher@ritehite.com.
FEature Story
Photo courtesy Soprema
Theory of a 
Self-drying Flat Roof
By Rockford Boyer
A
n effective method for a contractor, designer, or manufacturer to visit the inside of a court room is for the building enclosure to develop a leak! A 2011 article in the Journal of the American Institute of Architects revealed 40 per cent of issues are caused by moisture.1 With water vapour-related issues making up almost half of the problems, 70 per cent of the litigations interviewed had one issue in common—the roof.
The moisture-related roof issues discussed in the journal could be broken down into the following causes:
• 
60 to 70 per cent was attributed to poor construction methods and workmanship;
• 
20 to 25 per cent was the cause of poor design; and
• 
the remaining 10 per cent was due to material failure.
The roof enclosure is one of the most important components of the building. However, the average cost for the roof is approximately two per cent of the overall construction cost, as per the article mentioned above. Even if the overall roof cost increases, the chances for a leak-free assembly will almost be impossible if it is badly designed, have poor construction techniques, and lack third-party inspections.
Moisture ingress at the roof level has the potential to negatively affect the durability and resiliency of the enclosure, leading to an increase in operational and maintenance costs. Roof failures and wet roofs also have a large impact on the environment, such as the landfilling of waste materials and increasing carbon emissions with the manufacture and transportation of new products and increased heat flow.
Moisture ingress into the roof enclosure typically occurs through three conditions:
• 
physical bulk water entry;
• 
roofing material moisture content (construction moisture and through interior vapour diffusion) and;
• 
air leakage.
Bulk water leakage through the roofing membrane can be caused by commonly occurring damages from poor workmanship, such as blistering, incomplete laps, membrane punctures, wrinkles, splitting, abuse, and neglect, and inadequate penetration seals and flashing. Roofing materials, specifically moisture-sensitive ones, can become damp or saturated when installed or stored under wet conditions. The installation of an incomplete air and vapour membrane on the metal deck has the potential to allow moist air/vapour to enter the roofing enclosure through the mechanisms of diffusion and convection. Under certain conditions, the difference in pressures can help moisture-laden air and vapour to enter the roof enclosure and condense on the underside of the membrane. Since current construction practices allow the moisture to enter the enclosure, the introduction of a ‘smart’ roof design to promote self-drying will help increase the roof’s durability, resiliency, and thermal performance.

Thermodynamic solution
To develop a better understanding of how a roof works under specific environmental loads, an understanding of the second law of thermodynamics is necessary. In basic terms, the law says energy shall maintain a state of thermodynamic equilibrium—hot to cold, high pressure to low, and high to low vapour. In a cold climate, the roof will be hotter than the interior space under summer conditions. Therefore, the heat flow will be from hot to cold (exterior to interior). If a leak occurs at the roof membrane level during the summer (cooling season), the moisture will try to migrate from a high concentration area to one of low concentration, such as the roof enclosure to the occupied space below. The moisture will not be able to equalize as a vapour retarder would generally be located on the warm side of the insulation and does not allow for effective moisture transport to an area of lower concentration.
The conditions during the heating season are reversed as the heat from the interior occupied space will want to migrate up through the roof enclosure to the exterior colder temperature. Moisture will follow the same path as the heat during the winter months (hot to cold). Due to the vapour pressure and cold temperatures, if the vapour retarder is not continuous, there will be a possibility of condensation at the underside of the roof membrane.
An incomplete or defective roof membrane/vapour retarder will allow air, vapour, and moisture to enter the roof enclosure and migrate freely based on the interior and exterior conditions, thereby negatively impacting the roof’s performance and durability. The enclosure must be allowed to achieve equilibrium to increase its resiliency.
New construction materials can help roof enclosures equalize (dry) when wet—two such technologies are vapour permeable thermal insulation and variable vapour permeable smart vapour retarder (Figure 1). Drying to the interior can theoretically be achieved by replacing the standard non-vapour permeable insulation (traditionally polyisocyanurate [ISO]) with vapour permeable (mineral wool) insulation, and using a variable vapour permeable smart vapour retarder instead of a standard vapour retarder. Inward drying at the vapour retarder interface of the roof enclosure is recommended as there needs to be an ultra-low vapour permeable membrane protecting the components and space below.
The intent of using two vapour ‘open’ materials is to efficiently diffuse and dry the moisture from the area of high concentration (leak) to the area of low concentration (interior occupied space) by using the second law of thermodynamics and energy from the sun.
Theoretically, during the cooling season the moisture/vapour will diffuse through the vapour permeable insulation (via the variable vapour permeable smart membrane) and to the interior where the moisture could be removed by means of venting. The energy from the sun (membrane colour) will impact the drying period as the amount of radiation absorbed will dictate the temperature gradient through the roof enclosure. During heating days, the roles will be reversed due to the temperature’s gradients (i.e. inside to outside). While this scenario makes sense in theory, can it work in practice and possibly be modelled to demonstrate the ‘in-situ’ performance?

Test hut and lab testing
Modelling is a good tool to help designers predict how a scenario can play out. However, to ensure the model is as realistic as possible, infield testing data should be conducted, and inputted into the model. To determine if the self-drying roof is viable for a cold climate, a third-party test hut and a conditioned room was utilized to test components of the proposed system. The composition of the roof included two-ply modified bitumen roof membrane, two layers of 76-mm (3-in.) vapour permeable mineral wool insulation, smart membrane (permeability dependent on relative humidity [RH]), and a metal deck with holes drilled in to simulate screw holes. The test huts’ interior conditions were typical to operational interior conditions of 22 C (72 F) +/– 3 C (37 F) and 30 per cent RH +/– five per cent, whereas the exterior conditions were the actual climatic conditions in Waterloo, Ont., from June 6 to 10, 2016. To obtain the temperature, humidity, and moisture profiles, sensors were installed horizontally and vertically throughout the test roof enclosure. Moisture was introduced into the roof enclosure at the interface between the two mineral wool roof insulation via a simulated leak of 75 ml (0.15 oz) scheduled twice a day for five days (total of 750 ml [26 oz]). The 75-ml amount was chosen for testing and the intent was to see if the moisture could be removed in a reasonable amount of time (rhe test team plans to validate the drying rate and input that into the model so the amount of moisture in the model could be adjusted accordingly). Operational data obtained from the test roof enclosure’s temperature, humidity, and moisture sensors were then plotted. This would be used for the validation of the hygrothermal model.
Since material property data required for the self-drying roof enclosure was unavailable in a WUFI software database, relevant testing had to be completed on the smart membrane and the fluted metal roof deck. ASTM E96, Standard Test Methods for Water Vapour Transmission of Materials, was used to determine the vapour permeance of both the membrane and deck. Vapour permeance data was obtained for smart membrane by utilizing ASTM E96’s dry cup and wet cup methods. The vapour permeance data for the fluted metal deck was obtained by just using the dry cup method. However, to simulate in-situ conditions, several samples were created introducing side laps, end laps, and screw holes. The smart membrane had a wide vapour permeable performance ranging from 43 ng/pa.s.m2 (0.75 perms) to 550 ng/pa.s.m2 (9.65 perms) based on low and high RH. Surprisingly, the metal deck had a range of 14 ng/pa.s.m2 (0.25 perms) for side lap joints and an average of 68 ng/pa.s.m2 (1.2 perms) for end lap joints and screw holes in the fluted metal roof deck. Data obtained from these lab tests were added into the WUFI database to develop a validation model.

Validation and North American hygrothermal models
Accurate model predictions can be achieved in WUFI by including data inputs from actual laboratory testing. The WUFI validation model was created using the identical construction materials/orientation and was modified to mimic the data from the test hut roof enclosure. Many hours were spent developing various iterations to mimic the in-situ data from the test hut. However, the final validation model’s drying was within 0.5 per cent of the drying time of the actual test hut roof enclosure. The test hut roof assembly had a drying period of 816 hours (34 days) and the WUFI validation model had a drying period of 812 hours (33.8). It should be noted the test hut roof enclosure’s leak was between the two mineral wool boards whereas the validation model’s leak was located at the interface of the roof membrane and mineral wool board.
Seventy-eight hygrothermal models were created in WUFI, covering 13 climatic regional zones across North America, with three colour roof membranes (white, grey, and black). All modelled roof assemblies comprised a roof membrane, mineral wool thermal insulation, smart membrane, and metal deck. The thickness of the mineral wool insulation was dictated by the thermal requirements of the climatic regional zone for which the roof enclosure was being modelled. Both active and passive ventilation were introduced in the metal deck flutes (half the models) to minimize the diffusion of moisture into and out of the roofing assembly. The WUFI model simulation began on October 1, 2016, and continued for 8760 hours, ending on October 1, 2017. The 750-ml water leak was introduced on April 1, 2017, as one wetting event occurring at the interface between the roof membrane and the mineral wool insulation. The drying period for the 78 models was plotted and a performs/caution/warning designation was identified for each scenario. A successful self-drying roof was dependent on two criteria:
• 
the insulation did not increase in moisture content of 0.8 per cent by volume; and
• 
a drying period longer than 2880 hours.

Conclusion
Since 78 WUFI models were simulated, it would be difficult to describe all the models with their drying profiles. For the purpose of this article, four models are explained. Figures 2 and 3 (pages 30 and 31) are the self-drying models from Toronto with a white and black roof membrane and ventilation moving moisture out of the metal roof deck’s flutes. It is important to note the baseline was no ventilation moving the moisture out. Ventilation had to be added, as there was increased moisture. As previously mentioned, the beginning of the WUFI model began October 1, 2016, and the simulated leak occurred April 1, 2017 (as indicated on the graphs). There was minimal moisture ingress into the roof enclosure during the winter months, even with a smart membrane due to the ventilation introduced between the metal deck roof flutes. This ventilation allowed for the vapour attempting to diffuse into the roof assembly to be greatly reduced—the effect of this reduction will be evident when ventilation is not occurring. The black roof membrane assembly in Toronto (Figure 2) dried in nearly half the time of the white membrane roof assembly in Toronto (Figure 3). A higher membrane temperature and high vapour pressure were critical to the effective diffusion of the moisture/vapour to the interior. Based on the graphs, it appears the roof drying was effective when a single wetting event took place. If several wetting events had occurred, the results would be different. In a colder climate such as Edmonton (Figures 4 and 5, pages 31 and 32), by not venting the moisture attempting to diffuse into the roof enclosure, there will be added diffused moisture due to the installed smart membrane. Even in Edmonton, if a black membrane is used in conjunction with a self-drying roof enclosure there is still enough energy to diffuse the moisture to the interior, where it can be accommodated. On the other hand, the white roof does not have adequate energy to move all the moisture out of the system before the interior moist air reverses and diffuses back into the system (around mid-September). In this scenario, the author does not believe a self-drying roof with a white membrane will be an acceptable approach.
The tight time constraints of planning, designing, and constructing have placed a strain on available resources, especially finances and labour. A saying in the construction industry is, “Speed, Quality, and Cost—you can pick two, but you cannot have three.” Developing durable and efficient building enclosures, even when problems arise, should be the way of the future. Developing a self-drying roof enclosure would be a giant step forward in minimizing the monetary impact of construction on an owner and the environmental burden on society.
The proposed self-drying roof design was developed with economics, environment, durability, and ease of construction in mind. The roof membrane is to be continuous and have very low vapour permeability and a specified colour to suit the respective climatic zone. The thermal insulation in the assembly is to be a highly vapour permeable insulation material with a varying smart membrane below the insulation. Ventilation of the metal deck may be required in some climatic zones to remove the vapour attempting to diffuse into the roof assembly.
Results from the 78 hygrothermal models prove the potential for a self-drying roof enclosure is suitable in almost every location (Figure 6). Several outliers show self-drying roof enclosures with a white membrane were not ‘functional’ in colder climates. The performance of this self-drying roof enclosure design could minimize the rate of litigation and provide the additional benefits of increased resiliency and reduced financial burden for building owners and the environment. Though there is much more work required with modelling and testing, the design of a self-drying roof enclosure appears to have some promise.
With the life cycle of standard roof systems (typical industry types) averaging 17 years, the potential for increased durability and resiliency is needed. A self-drying roof system will allow for increased material performance and longevity, as the insulations’ effectively recover when moisture loading occurs. The cost of the overall system will increase by 30 to 35 per cent, but if the roof system can reach the industry standard 25-year warranty (with proper maintenance) the operational and environmental costs could be reduced. 

Note
1 Visit www.architectmagazine.com/technology/when-it-leaks-it-pours_o for more.
Figure 1
Images © Rockford Boyer
Illustration of a self-drying roof enclosure.
Both wet cup and dry cup vapour permeability testing per ASTM E96, Standard Test Methods for Water Vapour Transmission of Materials, was conducted on the smart membranes.
Sample of metal deck for ASTM E96 vapour permeability testing 
in a conditioned lab.
Figure 2
The self-drying roof model from Toronto with a white membrane and ventilation moving moisture out of the metal roof deck’s flutes.
Figure 3
The self-drying roof model from Toronto with a black membrane.
Figure 4
A black, self-drying roof model from Edmonton.

Figure 5
A white, self-drying roof model from Edmonton.
Photo courtesy Soprema
There is a need to increase the durability and resiliency of roof systems as the life cycle of standard assemblies is an average of 17 years.
Figure 6 
Self-drying Roof Enclosure – Location Functionality	
Location	Passive	 0 ACH	 	Active	 5 ACH	 	
 
CANADA	Black	Grey	White	Black	Grey	White	
				 		 	
St. John’s, N.L.	 	 	 	 	 	 	
Vancouver, B.C.	 	 	 	 	 	 	
Montréal, Qué.	 	 	 	 	 	 	
Toronto, Ont.	 	 	 	 	 	 	
Edmonton, Alta.	 	 	 	 	 	 	
 				 		 	
UNITED STATES OF AMERICA				 		 	
Miami, FL	 	 	 	 	 	 	
Houston, TX	 	 	 	 	 	 	
Los Angeles, CA	 	 	 	 	 	 	
Ney York, NY	 	 	 	 	 	 	
Chicago, IL	 	 	 	 	 	 	
Boise, ID	 	 	 	 	 	 	
Fargo, ND	 	 	 	 	 	 	
Fairbanks, AK	 	 	 	 	 	 	
						 	
Legend	 <2300 h	Performs	 >2300 h	Caution	 2880 h	Warning	

Results from the 78 hygrothermal models.
Rockford Boyer 
is the technical manager, building enclosure at Elastochem Specialty Chemicals. He has a diploma in civil engineering, a degree in architecture (building science option), and a master of building science degree. Boyer has more than 15 years of experience in the enclosure design field, including five years with AMEC, Earth and Environmental, 10 years with Roxul/Rockwool Insulation, and two years with Elastochem. He can be reached 
at rboyer@elastochem-ca.com.
FEature Story
Images courtesy Dörken Systems Inc.
The Detrimental Effects of UV on
Barriers
By Peter Barrett
I
n any construction project, it takes a combination of the right products and skills to achieve a high-performing building system. In the case of the building envelope, water-resistive barriers (WRBs) play a vital role in the performance of the wall system. Unfortunately, many building professionals may not realize the effectiveness of the barriers can be undermined even before they clad the exterior walls.
The concern is ultraviolet (UV) exposure. Experiential and anecdotal evidence of spun-bond polymeric (polypropylene) WRB membranes deteriorating in the sun after being left exposed for extended time periods prompted an investigation into the effects of UV effects the membrane.
Independent, accredited research commissioned by the author’s company, a manufacturer of air and moisture barriers, has shown when polypropylene WRB membranes are left exposed for as long as it is considered allowable (typically 180 days), it can lose as much as 90 per cent of its original water-penetration resistance. This loss not only has an impact on the effectiveness of the WRB, but also on the performance of the entire wall system because without effective protection, integral structural components are exposed to excessive moisture. This exposure causes all layers of the wall system to degrade, thereby leading to costly repairs.
Understanding and minimizing the impact of UV on WRB is critical to ensure the integrity of the wall system and building performance for many years.
The impact of a failing WRB
As a key component of the perfect wall, part of a WRB’s role is to protect sheathing from liquid water while allowing moisture to escape from inside wall cavities, and, when installed as part of an air barrier system, the WRB will also resist air movement both out of and into the building. Whether designing the wall or building or paying for it, professionals expect it to be fully functional for the lifetime of the building, maybe 50 years or more. This means each component of the wall, especially the WRB, needs to work and deliver on these expectations.
When any part of a wall system is compromised, it can have adverse effects on the performance of a building. Damaged or under-performing WRBs can cause costly failures and long-term inefficiencies, including:
• 
damage to insulation, wood, and other structural components due to moisture infiltration;
• 
mould and air quality concerns from wet wall systems;
• 
increased energy costs and discomfort for building occupants; and
• 
potential damage to relationships, reputation, and bottom line brought on by expensive repairs or warranty issues.
To put it into perspective, if the aging process of any WRB is accelerated due to excessive UV exposure, the product may only perform as expected for a few years.

How UV breakdown occurs
WRBs can get damaged; it is a fact of construction. Most physical damage happening to barriers prior to or during installation can be seen. Holes, cracks, and tears can have a significant impact on a WRB’s effectiveness. These are usually caught and repaired onsite because they are visible. Unfortunately, this is not the case with UV damage. This impact happens at the molecular level, leaving building professionals unaware of and unprepared to deal with the problem.
UV exposure occurs from the time of installation until the WRB is covered with the exterior insulation or cladding. During this period, UV radiation causes the WRB to oxidize, age, and deteriorate. The rate and amount of damage at a molecular level are determined by many factors, including additives such as:
• 
colour pigments;
• 
antioxidants;
• 
UV stabilizers; and
• 
flame retardants.
How the WRB is manufactured will also have an impact on the degree of breakdown. For instance, manufacturing processes including thermal or shear stresses can initiate early degradation of the WRB. The material experiences heat from the friction that is part of the production process. Higher temperatures cause the polymer molecular chain to break down and react with one another to change the properties of the polymer.
This became common knowledge in the science community as early as 1899 when a Swedish chemist performed experiments that correlated chemical reaction rate constants with temperature. From this research, the Arrhenius Equation theory indicates a 10 C (18 F) rise in temperature will reduce the lifespan by half. Oxidation also has a significant impact on the aging and breakdown of WRBs, which can occur as a result of exposure to heat, certain chemicals, or UV light.1 This means over-ambitious production methods leading to excessive heat and stress can kick off the degradation process well before the material lands on a jobsite. For polymers, more heat equals rapid aging. So, while a WRB may not physically break down during the allowed exposure time, it is important to understand what happens to the product once it is no longer visible.

Uncovering the unseen damage
To better understand what happens behind closed walls, an Sageos (a division of the CTT Group) carried out a series of third-party, accelerated aging tests on vapour permeable, self-adhered WRBs.2 The research spanned eight months from April to November 2013.
Standard UV exposure tests (such as those required by the International Code Council [ICC] Acceptance Criteria [AC] 38, Water-resistive Barriers, or the Underwriters Laboratories of Canada [CAN/ULC] S741, Standard for Air Barrier Materials—Specifications) use the WRB product samples and expose them to light from UV sun lamps for 10 hours per day for a total of 21 days. In theory, these tests are designed to mimic the conditions naturally occurring in a construction site. These relatively short-term tests do not represent a typical exposure time for WRBs, as some are exposed for nearly 180 days.
As part of the research study, new samples were tested for strength, elongation, and water resistance before being exposed to the UV light to establish a baseline. Those specific tests were chosen to represent the two key, long-term performance criteria one would expect from a membrane in a wall system:
• 
resistance to water penetration (Hydrostatic Head Tester per the American Association of Textile Chemists and Colorists [AATC] 127-2008, Water Resistance: Hydrostatic Pressure Test); and
• 
durability (ASTM D5035-11, Standard Test Method for Breaking Force and Elongation of Textile Fabrics [Strip Method]).
The samples were retested after 500 hours of UV exposure and again after 1000 hours of UV exposure, using Cycle 3 of ASTM G155, Standard Practice for Operating Xenon Arc Light Apparatus for Exposure of Non-Metallic Materials.
It is important to note natural UV exposure varies widely according to geographic location, site conditions, and weather. The 500- and 1000-hour intervals were chosen for all samples to provide consistent and equal exposure for accurate comparison.
Totally, five common self-adhering WRBs were tested, with the acceptable or ‘pass’ criteria set at a minimum of 75 per cent retention of original (‘as new’) test results. All saw a reduction in performance with respect to strength, elongation, and water resistance. The strength of some barriers declined by 80 per cent after being fully exposed for 1000 hours. Even at 500 hours, two of the five WRBs experienced a reduction in strength of 40 per cent or more.
Elongation results and measures of durability were also seen to decline for most products after the full 1000-hour exposure, with four of the five experiencing a reduction of more than 50 per cent. The most significant results, however, came from testing the water resistance of the WRBs. Two products saw a 90 per cent decline in water resistance after just 500 hours of exposure and continued to decline during the remaining exposure hours.
Overall, test results made it clear WRB damage does occur from extended UV exposure during installation periods and the effects can be severe. All WRBs would perform better with less exposure to UV radiation on the jobsite. The sooner the WRB is covered after installation, the less degradation and aging can be expected, and the better its long-term performance within the building envelope. With the right planning and approach, steps can be taken to get ahead of the problem and minimize the impact.

Getting ahead of UV damage
Many building professionals instinctively turn to manufacturer data sheets for the information they need to select products. In the case of long-term UV exposure, there is no ASTM standard on which manufacturers may base their claim of acceptable jobsite exposure times. However, if this recent UV research has proven anything, it is that more needs to be done outside of this effort to find a solution that best suits the needs of the project. Below are some simple steps to consider when selecting a product.
Know the UV radiation expectations at the site 
Understanding the UV radiation expectations at the site can help building professionals plan appropriately for optimal product selection and time demands for exterior cladding installation. For instance, Figure 1 illustrates the UV index for North America in July.
Minimize exposure of WRB to UV
It is advisable to include specifications and schedule details to install the exterior insulation or cladding as soon as possible after the installation of the WRB. By minimizing exposure, one can limit the impact UV will have on long-term performance.

Revisit the impact of failed WRBs used in the past
If building professionals experienced the negative effects of a failed WRB in past projects, it is best to remember the exposure time on that site.

Ask the manufacturer for more information
Reaching out to the WRB manufacturer for more information will come in handy. They should provide information on how the product is manufactured, and some may have data specific to the long-term performance of the material, as well as recommend UV exposure times. Others, however, may not have any test results. It is important to remember a manufacturer’s representative cannot detect molecular damage through a visual check.

Conclusion
Deciding on the best WRB for a project should rely on more than the information provided in manufacturers’ marketing materials. Understanding specific project challenges, exposure rates, schedule demands, and WRB needs will ultimately help one give better results, extend the life of the building, and provide the best performance. 

Notes
1 For more information, visit chem.libretexts.org/Bookshelves/Physical_and_Theoretical_Chemistry_Textbook_Map.
2 Visit gcttg.com/en/lab-testing-services/geosynthetics.
Water-resistive barriers (WRBs) are fundamental to the perfect wall because they protect sheathing, allow for the escape of moisture from inside wall cavities, and, when installed as part of an air barrier system, some WRBs can resist air movement both into and out of the building.
Site conditions, especially ultraviolet (UV) light, have an impact on the long-term performance of the water-resistive barrier (WRB).
Achieving the perfect wall means creating a building envelope that includes effective water, air, thermal, and vapour control layers between the exterior finish and the interior structural wall.
Figure 1
Image courtesy World Ozone and Ultraviolet Radiation Data Centre
Ultraviolet (UV) index in July for North America. 
Photo © Getty Images
Peter Barrett is the product and marketing manager for Dörken Systems. He has been with the company for more than 12 years. However, his involvement with the design community and building materials industry spans over 25 years. Barrett holds a BA (Hons.) from Queen’s University, Kingston, Ont., and an MBA from Wilfrid Laurier University, Waterloo, Ont. Barrett is a board member of the Air Barrier Association of America (ABAA). He can be reached at pbarrett@dorken.com.

Damage to WRBs from UV light may not appear until well after the exposure has happened, and often when the wall is completely enclosed.
TOOLS OF THE TRADE
Designing to Reduce a Building’s
Embodied Carbon
Photo courtesy Dialog
By Stephanie Fargas
T
he carbon footprint of the design and construction industry reaches far beyond the boundaries of a single building or site. Due to various processes, ranging from the extraction of raw materials to manufacturing and installation of the construction materials, the impact of a single project includes both embodied carbon within the built environment and operational carbon generated throughout the life cycle of the structure. Embodied carbon is defined as the carbon dioxide (CO2) emitted during the full life cycle of a product from extraction (cradle) to the use and disposal phases (grave).
Construction products contribute to 11 per cent of global greenhouse gas (GHG) emissions.1 Canada’s GHG emissions from the built environment is 17 per cent (residential, commercial, and institutional buildings).2 There has been significant strides in reducing operational carbon by improving the energy efficiency of mechanical and electrical systems, and integrating renewable energy resources. However, designing to reduce embodied carbon has not been an area of emphasis in the design community, or a mandatory policy in Canada.
With recent efforts from Architecture 2030 (the American Institute of Architects [AIA] 2030 and 2050) and sustainability certification programs, such as the Leadership in Energy and Environmental Design (LEED), Envision, and the Living Building Challenge (LBC), awareness has been raised on the importance of designing for low embodied carbon to address climate change.
This lack of emphasis has not prevented the design and construction industries from taking heed of the urgency of the current climate crisis or from utilizing available tools to plan and execute buildings that are both beautiful and low-carbon or carbon-neutral. In fact, the opportunities for these industries to become leaders in carbon solutions are just beginning to be tapped. This article focuses on how the industry can design for low embodied carbon solutions in new and existing buildings.
Architecture 2030 was established by AIA in 2006 to address climate change through sustainability-driven solutions and carbon-neutral design in the built environment. It established targets toward zero emissions including a 70 per cent reduction in GHG related to energy consumption below a comparable building type for new and existing structures in specific geographical locations. Since its establishment, more than 1200 design, architecture, and engineering firms have signed on to monitor their progress toward the agreed-upon goal. Additional metrics were established for subsequent years—for example, by 2020 an 80 per cent reduction, 90 per cent in 2025, and carbon-neutral in 2030 (i.e. complete elimination of fossil fuel sources from building operations). Further, AIA, the Royal Architectural Institute of Canada (RAIC), Ontario Association of Architects (OAA), U.S. Green Building Council (USGBC), Canada Green Building Council (CaGBC), and several countries, states/provinces, and cities have also advocated and adopted these policies. The CaGBC has developed the Zero Carbon Building Standard to address and achieve the climate change commitments Canada has signed onto and provide guidelines for zero-carbon design for new and existing buildings of various project typologies (e.g. institutional, commercial/office, residential, and commercial warehouses). Through this standard, projects are to demonstrate a net emissions balance of zero or less for building operations. Emissions generating GHG are offset by renewable energy sources on or offsite. Two projects have been certified as zero-carbon buildings—evolv1 in Waterloo, Ont., and Mohawk College’s Joyce Centre for Partnership and Innovation in Hamilton, and 16 projects are enrolled in the program. Currently, the Zero Carbon Building Standard is not mandatory, but rather a guideline for consultants and owners to follow.

Sustainability metrics
Through its LEED v4 reference standard USGBC has introduced the Building Life-cycle Impact Reduction credit under the Materials and Resources category. The credit’s fourth option allows project teams to conduct a whole building life-cycle assessment (LCA) on the structure to demonstrate a minimum 10 per cent reduction compared to a baseline facility in at least three of the following six impact categories:
• 
global warming potential (GWP);
• 
depletion of the stratospheric ozone layer;
• 
acidification of land and water resources;
• 
eutrophication (addition of nitrogen or phosphate entering into a water source as run-off causing accelerated aquatic plant growth and depleted oxygen levels);
• 
formation of tropospheric ozone; and
• 
depletion of non-renewable energy sources.
It is important to note the GWP category is mandatory. Additionally, no impact category assessed as part of the LCA may increase by more than five per cent compared to the base building.
With LBC, the International Living Future Institute (ILFI) requires projects to account for the total embodied carbon (tCO2e) impact from its construction with a one-time carbon offset from an approved provider, through Imperative 11 – Embodied Carbon Footprint. To comply, the project team is to incorporate carbon-reduction strategies during the design phase, and then purchase certified emissions reductions (CERs), carbon offsets through the institute’s new Living Future Carbon Exchange, or another acceptable third-party verified program to nullify 100 per cent of the CO2e.
The Institute for Sustainable Infrastructure’s (ISI’s) Envision program has a credit under Emissions—Credit CR1.1 Reduce Greenhouse Gas Emissions requires at a minimum a life-cycle carbon analysis and assessment to reduce the project’s anticipated net GHG. This credit offers teams various levels of achievement from ‘improved’ to ‘restorative’, with the latter being the highest, resulting in the project being classified as carbon negative (i.e. sequestering more carbon than produced).
From LCA to environmental product declarations (EPDs), there are various sources and methods of documentation for a project team to determine embodied carbon. An LCA serves as a tool for understanding the energy use intensity (EUI) and environmental impacts by considering all aspects of a building from extraction of raw materials used for construction, manufacturing and installing products, and decommissioning of the building, similar to the cradle-to-grave approach. The European standard EN 15978:2011, Sustainability of Construction Works – Assessment of Environmental Performance of Buildings, is used for whole building LCA. It identifies the calculation method and reporting requirements. In EN 15978, LCAs are conducted to determine the environmental impact of a product or building based on the six impact categories (Figure 1).

Environmental product declarations
EPDs with the supporting product category rule (PCR) and LCA contain information that can be utilized to determine whether a product can be incorporated into the project to reduce embodied carbon and its contribution toward the environmental impact categories. Before an EPD can be created a PCR is developed to define scope, impact categories, and measurement methods. PCR can be created through assistance and guidance from industry leaders such as associations, governments, and reference standard committees. PCRs are meant to be objective, defining documents serving as the framework for conducting LCAs. PCRs help promote fairness by ensuring all the similar products are measured with the same metrics. PCRs are often initiated as a request from a manufacturer wanting to develop a product-specific EPD. This request is sent to a program operator such as:
• 
ASTM International;
• 
ICC Evaluation Service (ICC-ES);
• 
Institute for Environmental Research and Education (IERE);
• 
NSF International;
• 
SCS Global Services; and
• 
Underwriters Laboratories (UL) Environment (Figure 2, page 42).
An EPD conforms to the International Organization for Standardization (ISO) 14025: 2006, Environmental labels and declarations – Type III environmental declarations – Principles and procedures, ISO 14040: 2006, Environmental management – Life cycle assessment – Principles and framework, ISO 14044: 2006, Environmental management – Life cycle assessment – Requirements and guidelines, and EN 15804:2012, Sustainability of Construction Works – Environmental Product Declarations – Core Rules For The Product Category Of Construction Products, or ISO 21930: 2017, Sustainability in buildings and civil engineering works – Core rules for environmental product declarations of construction products and services. EPDs are classified into two main categories:
• 
industry-wide (generic) – type III; or
• 
product-specific – type III. 
Type III means the product has been verified and certified by a third-party program operator. An industry-wide EPD is verified and is generic to a product type (e.g. gypsum board) but is not specific to a manufacturer. For eligibility, manufacturers are to provide representation in the EPD development either directly or through the program operator. A product-specific EPD is verified and is distinct to a manufacturer as it reflects particular aspects of the production process. These EPDs can be used to conduct a whole building LCA. If a project team wants a specific basis-of-design product, a product-specific EPD can be utilized to research a particular manufacturer’s environmental performance.
When a design team chooses to establish low embodied carbon as criteria for a project, it is important to set targets, develop a strategy for achieving the goals, prioritize products and materials that will be assessed to determine their embodied carbon contribution and potential reduction, and conduct a building LCA. Some strategies include but are not limited to: 
• 
identify the project goal for embodied carbon and the scope of LCA (e.g. what components will be included in the LCA);
• 
determine the LCA tool and life-cycle inventories (LCI) data source to use;
• 
identify products’ and building components’ ‘hot spots’ (i.e. highest impact potential) that can contribute to reduction in embodied carbon;
• 
evaluate the different material types, estimated quantity for each, and anticipated service life;
• 
explore the possibility of reusing the building structure and/or salvaging building materials to reduce embodied carbon;
• 
assess options for the material of the building structure to optimize design, utilizing renewable resources (carbon sequestering opportunities) for structures such as heavy timber, or incorporate recycled content such as fly ash or CO2 as an additive alternate to Portland cement to optimize the concrete mix design; and
• 
design buildings for long service life expectancies (e.g. 50 to 100 years).
When conducting an LCA it is important to maintain consistency in the tool being utilized, as LCI sources vary within the tools and the data may not be comparable or classified differently. Similarly, if an EPD will be used, the referenced PCR needs to be the same amongst the EPDs being compared.

Tools in the market
Numerous tools and resources are available to the design community to guide design choices, including:
• 
Architecture 2030 offers the ‘Carbon Smart Materials Palette,’ which is a guideline offering options for reducing emissions (it can be utilized when conducting an LCA and evaluating EPDs);
• 
Architecture 2030 also has the ‘EPD Quicksheet’ to simplify the review and evaluation of EPDs; and
• 
the Carbon Leadership Forum offers the ‘Life Cycle Assessment of Buildings: A Practice Guide,’ a guideline meant to assist the design community with understanding the purpose of an LCA and how to conduct one.
The design and construction industry can take the lead and facilitate market transformation. Additionally, clients can utilize LCAs to benchmark the sustainability performance and carbon footprint across their building portfolio, and identify areas of improvement.
The design and construction industry has an opportunity to holistically design buildings to reduce the impact of climate change by advocating for greater transparency in the embodied carbon data of building materials/products, incorporating sustainable design solutions with reduced embodied carbon, and establish embodied carbon as a primary design consideration as opposed to a secondary thought.

Case study
Designing for embodied carbon was a consideration in the University of Calgary – MacKimmie Complex and Professional Faculties Redevelopment project. It is also registered as a pilot project with the CaGBC Zero Carbon Building Program. During the schematic design phase, the consultant with participation and guidance from the owner’s representative conducted a facility assessment of the existing structure to determine opportunities for sustainable building repurposing. The evaluation included determining the inherent monetary value of the existing structure as well as the embodied energy of extraction of raw materials, transportation, construction of a new building, and demolition and disposal of the existing structure. A key consideration for calculating the embodied energy was to identify the regional and international differences in the measurement of embodied energy for material types—for example, reinforced concrete differs based on region, source/extraction methods of raw materials, energy sources, electrical production, and transportation. Once the assessment was completed it was determined retaining a significant portion of the structure allowed for a reduction in the embodied energy that would have been generated from a traditional design approach of demolishing the existing structure and constructing a new one.
Through an integrated design process the main project participants had contributed to identifying sustainable strategies to address embodied carbon. Products were evaluated on its anticipated service life and opportunities for optimizing the design. 

Notes
1 For more information, read the 2017 and 2018 United Nations (UN) Environmental Global Status reports.
2 Consult the 2016 Pan-Canadian Framework on Clean Growth and Climate Change.
Photo © BigStockPhoto.com
The building industry can help fight climate change by adopting solutions with low embodied carbon.
Figure 1
Images © Stephanie Fargas, Dialog

A life-cycle assessment considers all aspects of a building from extraction of raw materials to decommissioning.

Figure 2
Steps to follow when developing an environmental product declaration (EPD).
Photo courtesy Dialog
Through an integrated design process, the University of Calgary – MacKimmie Complex and Professional Faculties Redevelopment project team identified sustainable strategies to address embodied carbon.
Stephanie Fargas is a specification writer for the Calgary office of Dialog with eight years of experience in a variety of project typologies. She works with Dialog’s specifications team developing project specs, conducting sustainable product research, and liaisoning between consultants. She leads the research and development of specifications for Dialog’s first Living Building Challenge (LBC) certification and the Leadership in Energy and Environmental Design (LEED) Platinum project, Bill Fisch Forest Stewardship and Education Centre in Ontario. Fargas can be reached at sfargas@dialogdesign.ca.
feature story
Images © BigStockPhoto.com
Standardizing 
Power-operated Doors
By Michael Tierney

N
ew technologies can impact everyday life experiences like walking into a grocery store to vacationing at a new family resort. One often overlooked technical connection between these two locations is that both buildings likely use power-operated doors, whether sliding or revolving.
Power-operated doors come in a variety of designs and styles to fulfill the functions of the building envelope and interiors. Among the considerations are reliability, safe egress, accessibility, energy conservation, security, and esthetics. The following four standards cover the breadth of power-operated door products:
• 
the American National Standards Institute/Builders Hardware Manufacturers Association (ANSI/BHMA) A156.10, Power-operated Pedestrian Doors;
• 
A156.19, Power Assist and Low Energy Power-operated Swinging Doors;
• 
A156.27, Manual and Power-operated Revolving Doors; and
• 
A156.38, Low Energy Power-operated Sliding and Folding Doors.

ANSI/BHMA A156.10
This standard covers power-operated doors intended for regular pedestrian use—implying the doors will open automatically when approached by pedestrians and, in some cases, small vehicular traffic. These include swinging, sliding, and folding doors with hardware such as guide rails, knowing act door activation devices (e.g. an automatic door push button), control mats, and sensors.
Power-operated pedestrian doors are commonly specified for accessible routes. As the installation of power-operated pedestrian doors increased, it became apparent this standard was needed to reduce the risk of injury or entrapment because these doors are often installed in areas where heavy foot traffic needs to be accommodated.
A key component of this standard is signage. Signage for power-operated pedestrian doors is required to indicate it is an automatic door, and, depending on the door, dictate direction, caution, and what to do in case of performance failure. These signs include the well-known ‘automatic door,’ ‘slow speed activation,’ and ‘emergency stop’ signs. ANSI/BHMA A156.10 indicates the necessary font, colour, size, and visibility for the various power-operated pedestrian doors.
Another highlight in this standard includes entrapment protection for users to reduce the chance of the automatic door closing on an object. Depending on the door, entrapment protection contains requirements for door opening times, the degree at which a door can open, the force required to prevent a stopped power-operated door if needed, closing speeds, and latch checks. For example, it is noted the time required to open a swing door to 80 degrees shall not be less than one-and-a-half seconds; and the force required to prevent a stopped power-operated swinging door in the last 10 degrees of opening from moving in the direction of opening shall not exceed 133 N (30 lbf) measured 25 mm (1 in.) from the lock edge of the door.
A knowing act references the action of triggering a mechanism for a door operator, such as pressing a switch with the knowledge it will open the door in connection with that switch. As covered in ANSI/BHMA A156.10, once the knowing act device is switched or released, the power-operated pedestrian door shall remain open for a minimum time delay of five seconds. If the knowing act device is located more than 4 m (12 ft) from the centre of the door, the time delay shall have an added second for each additional foot. If a knowing act device is 4.5 m (15 ft) away from the centre of the door, the time delay shall be a minimum of eight seconds.
ANSI/BHMA A156.10 accounts for a cycle test, too, and a salt spray test for 168 hours to ensure the critical parts of the assembly are resistant to corrosion and retain their operability. This standard does not account for a low-energy, power-operated door and does not include fire exits and emergency doors. Additional specifications for this standard include control mat layouts, sensor zones, guide rail details, and further knowing act door activation device installation conditions onsite.

ANSI/BHMA A156.19
A low-energy, power-operated door is one that opens once a knowing act is activated and signalled, adheres to the maximum amount of kinetic energy allowed by this standard, and is closed by a power mechanism or other means. These doors are intended to improve accessibility.
Unlike the previous standard, ANSI/BHMA A156.19 addresses power-assist/low-energy, power-operated doors, but only for the automatic swinging type. The swing door operators in this standard are assessed for pedestrian, and some small vehicular, use. However, this standard neither regulates doors, finish, or hardware nor doors requiring higher speeds, forces, shorter time delays, and activating sensing devices. Further, each door activation described for power-assist/low-energy, power-operated, swinging doors requires a knowing act. Just as before, the intent of this standard is to prevent injury and entrapment.
Requirements for low-energy, power-operated doors involve an opening speed in which the door will progress from closed to backcheck—or 80 degrees—in three seconds or longer. In this instance, backcheck shall not occur before 60 degrees, and any door opening wider than 90 degrees will continue to open at the same rate as the backcheck speed. These doors shall stay open for five seconds or longer unless push-pull activation is used. In that case, it shall remain open for three seconds or longer.
Requirements for power-assist and low-energy doors are separated in this standard. These requirements primarily consist of signage specifications in the instances of separate switches, the use of remote devices, identifying low-energy doors, and knowing act switch identifiers and when push-pull activation is used to initiate the operation of the door operator.
A primary test for ANSI/BHMA A156.19 determines the durability of the item. A test for durability requires the action of 300,000 cycles with the actual opening and closing time to be within a percentage of the values at the commencement of the test.
Overall, this standard does not attempt to assess any factors that exist with respect to custom design installations.

ANSI/BHMA A156.27
While this standard concerns manual revolving doors for pedestrian use, the power-operated types (i.e. doors rotating automatically when approached by pedestrians and some small vehicular use) are the primary focus. The included criteria are provisions to reduce the chance of user injury and entrapment.
Covered doors include automatic, revolving doors with a core. These doors contain a large diameter and have about three to four wings attached to a central core. The nominal diameter for the enclosure size is a maximum of 7 m (24 ft). However, two-wing, automatic, revolving doors have a nominal enclosure maximum diameter of 5 m (18 ft).
Other doors in this standard involve access-controlled, revolving doors. The wings on these doors are surrounded by an enclosure with the application for control by a knowing act and trained traffic. However, slow-speed operation and activation alongside wind sensors are inapplicable. Further, these doors are able to act on unauthorized entry as a control mat or sensor is permitted to stop or stop and reverse a door. If reversing, there shall be a delay of two seconds minimum and the reversing speed shall be one half of the standard speed.
The ultimate allowable speed is indicated in the full standard for each type of door depending on the diameter. For example, a 3-m (10-ft) diameter revolving door with a central shaft is limited to 5.7 revolutions per minute at standard speed.
Written examples of signage for power-operated revolving doors include the following: 
• 
automatic door;
• 
activate to slow;
• 
push to slow;
• 
press to slow; and
• 
emergency stop.
Additional topics covered in this standard include:
• 
access-controlled revolving doors with one-way passage;
• 
glazing;
• 
clearances;
• 
breakout forces;
• 
kinetic energy;
• 
obstruction force;
• 
manual revolving doors;
• 
slow-speed operation;
• 
wing sensors;
• 
end wall and bottom rail guard sensors;
• 
door out of position;
• 
emergency stop switches;
• 
activating devices; and
• 
entry point sensors.
Yet, revolving doors for industrial or trained traffic are not covered, and this standard does not attempt to assess any existing factors with respect to custom installations.

ANSI/BHMA A156.38
Similar to ANSI/BHMA A156.19, A156.38 predominantly differs in that it covers sliding doors as opposed to swinging types. As with the other standard, this one is for pedestrian and some small vehicular use, and the trigger of all doors described in this standard calls for a knowing act. Further, similar to A156.19, requirements include tests for durability using the 300,000 cycle test and mandates for specific signage specifications dependent on varying factors. Intentions for this standard are based on the desire to promote safety when using low-energy, power-operated sliding doors.
Low-energy, power-operated sliding doors comply with this standard if doors open at a maximum speed of 300 mm (12 in.) per second, close at a maximum speed of 152 mm (6 in.) per second, and remain open for a minimum of five seconds before beginning its closing cycle.
Low-energy, power-operated folding doors shall adhere to a total opening time to 90 degrees in a minimum of four-and-half seconds and will remain open for no less than five seconds before initiating its closing cycle. Unless provided with a finger guard, these doors require a specific clearance. The opening at the hinge side of the folding door can be less than 6 mm (1/4 in.) or a minimum of 19-mm (3/4-in.) wide with the door in any position.
This standard does not assess any existing factors with respect to custom design installations. Doors requiring higher speeds, forces, shorter time delays, and activating sensing devices are not covered in A156.38 and, as appropriate, shall comply with ANSI/BHMA A156.10.

Conclusion
When combined, these four standards encapsulate the safety means and implications for varying power-operated doors. While similar in content topics, the nuances of each standard provide building professionals the means to ensure the function of each of these doors is properly met with testing suitable for its cause.1 

Note
1 For more information on these standards, visit buildershardware.com/ANSI-BHMA-Standards.
Photo © Shutterstock
Representation of revolving doors.
Michael Tierney has served as the product standards co-ordinator for the Builders Hardware Manufacturers Association (BHMA) for 20 years, where he co-ordinates the development and revision of BHMA’s performance standards. He is a principal member on technical committees for the National Fire Protection Association (NFPA) and the International Code Council (ICC) A117.1 Committee for Accessible and Usable Buildings and Facilities. He also chairs the American National Standards Institute (ANSI) TAG 162 for Doors and Hardware. Tierney can be reached at mtierney@kellencompany.com.
Emerging Leader Awards
Photo © BigstockPhoto.com
Meet the finalists
of the Inaugural Emerging Leader Awards
Sponsored by:
E
arlier this year, Construction Canada launched its inaugural Emerging Leader Awards program. The awards, presented by Engineered Assemblies, honour members of the architectural, engineering, and construction (AEC) community who demonstrate excellence, impress, and inspire their co-workers, and are well on their way to becoming the next leaders in the profession.
Nominated by a member or members of their team, finalists were selected by a jury of peers. In the following pages, we provide a snapshot of the submissions that eloquently explain why each one of them is a finalist.
The winners will be announced at The Buildings Show, Metro Toronto Convention Centre (south demo area), on December 4, 2019, at 4 p.m. 
Emerging Leader Award – Leadership

Emerging Leader Award – Initiative
Kazim (Kaz) Kanani, CSP, CCCA
Senior associate and specification specialist, Quadrangle Architects, Toronto

The third vice-president of the Construction Specifications Canada (CSC), Kazim (Kaz) Kanani has made many contributions to the local community. He is one of Quadrangle Architects’ United Way campaign leaders, a team he has been part of since 2016. Additionally, he is a director for Canstruction Toronto, supporting the Daily Bread Foodbank, and volunteering in a variety of capacities for ISIJ of Toronto, a local mosque/community centre.
Further, he assists various industry associations when and where required to advance and for the betterment of the design and construction industry.
“At Quadrangle, he continues to impress us with his initiative, leadership, and teamwork. He is heavily involved in the culture of the studio, from the onboarding to career growth. No task is too big or small for him, and he is always willing to help,” said his nominee Kirsty Keefe, HR Lead at Quadrangle Architects.

Samantha Lane, CEM, CPHD, LEED AP, P.Eng.
Building performance engineer, Stantec, Calagry, Alta.

In her submission, Samantha Lane’s nominee Tanya Doran, senior associate, Stantec, said, “Sam epitomizes energy. She is an educator, advocate, and designer constantly pushing the boundaries of efficiency in the built environment. Her no-nonsense approach drives beyond net-zero energy to passive and regenerative strategies for new and existing buildings, a driver of more than 30 per cent of the carbon dioxide (CO2) in urban North American cities.”
Lane mentors the team of building performance engineers at Stantec in Calgary, Alta. She advocates for building performance with design professionals and teaches young professionals and students on evenings and weekends as an educator. She is always looking to improve energy outcomes, the client’s bottom line, and the social impacts of energy sources.
Heather Barnsley, Architect, 
AAA, AIBC
President, Ti STUDIOS Architecture, Calgary, Alta.

Heather Barnsley was nominated by her employee Faye Coburn, senior interior designer, BID, Ti STUDIOS Architecture. The sole proprietor and signing architect at Ti STUDIOS, Barnsley has successfully run her business for over a decade.
According to Coburn, Barnsley “encourages staff’s learning beyond in-house application by supporting extended education (updating technical drawing courses, further education relating to the Alberta Building Code [ABC]).”
“Heather’s tenacity to make this business a success is inspiring. Heather truly believes in providing her staff with the essential tools to become confident and successful in their careers. Heather’s vested interest in empowering young professionals is clear as she has provided placements for students’ work terms over the years (we currently have three work-term students!),” she added. “She leads by example and is without exception, the biggest supporter of her staff’s work and growth.”

Jesse X. Watson, CET
Specification writer, Number Ten Architectural Group, Winnipeg

Jesse Watson is also the chair of the CSC Winnipeg Chapter. At the 2018 CSC annual conference, he received the Award of Merit and Program Director Award.
Watson led the effort to introduce the Principles of Construction Documentation (PCD) course into the civil engineering technology curriculum at Red River College, Winnipeg. For that effort, Watson was named chair of CSC’s Education Entry Details User Information Program Advisory Committee, with the goal of introducing the same course to similar programs nationwide.
“Jesse’s approachable nature has encouraged a number of industry contacts, including myself, to reach out for clarifications and guidance related to construction documentation, which encourages improvement and a better understanding for each party involved, further benefiting the industry. The list of accomplishments and volunteer efforts are made more impressive with the fact that Jesse is still under the age of 30,” said his nominator Zeb Hudon, project manager, Penn-co Construction Canada.
David Carnovale, P.Eng.
Project manager, WSP Canada, Kingston, Ont.

According to Chris Woit, director, WSP Canada, David Carnovale is “seen as an up and coming leader in the organization for many years now.” He decided early in his career to get involved with WSP’s internal practice team and began organizing their national lunch & learns and technical presentations. Later on, Carnovale took over the management and leadership of the internal knowledge sharing intranet pages and helped transform it to what it is today.
“David has demonstrated leadership and teamwork through the numerous projects and practice work he has been involved in. David was recently promoted to a project manager, but has been providing leadership and training to many of the younger staff and new grads to help them develop their careers. Recently, David has been leading WSP’s efforts in technology with the adoption of Dynamo in their workflows. He has been a driving force and critical lead for this work that will help bring more efficiency and profitability to WSP,” explained Woit.

Mark Gaglione, P.Eng.
Construction sciences specialist, EllisDon Construction, Mississauga, Ont.

Mark Gaglione is an expert in building science and mass timber construction. He is knowledgable of mass timber supply chain, material composition, variations in material types, etc.
Gaglione has also participated in and contributed to the development of the Mass Timber Institute’s strategic plan. He’s an active volunteer at the TimberFever (a design festival for engineering students) for several years running.
He was nominated by Craig Applegath, OAA, FRAIC, founding principal of Dialog’s Toronto studio. Applegath and Gaglione worked on the Mass Timber Institute’s strategic plan. They are currently working on a hybrid wood tower prototype and on a post-secondary mass timber competition.
“In working with Mark over the past few years I have come to respect and admire his energy, intelligence, and generous willingness to help advance the AEC industry. His ability to communicate his vast knowledge to others (which I have seen myself on a number of occasions) is one of the things that makes him so deserving of the ‘Emerging Leader’ title,” said Applegath.
Claudio Nuñez, OAQ
Associate, Menkes Shooner Dagenais LeTourneux Architectes, Montréal

Claudio Nuñez is a member of the Ordre des architectes du Québec (Québec Order of Architects).
“Claudio stands out for his ability to invent and innovate. He brings a fresh perspective to projects, proposing ideas that exceed client expectations, and he does not hesitate to push the limits of an idea or of a project,” said his nominator Anik Shooner, co-founder of Menkes Shooner Dagenais LeTourneux Architectes. 
According to Shooner, Nuñez is curious and constantly looking out for new tools and technological discoveries. He used parametrization technologies to develop the artificial topography of the University of Montréal’s MIL Campus Science Complex. Recently, he co-ordinated the use of virtual reality to allow National Bank executives and employees to ‘visit’ their new headquarters, prior to construction. He also contributed to the project team’s use of simulation tools to validate natural/artificial lighting strategies to create well-illuminated spaces.
Kelly Fisher, CPHC
Director of BIM and building performance, Kearns Mancini Architects, Toronto

Kelly Fisher has been instrumental in applying building information modelling (BIM) Passive House Planning Package (PHPP) energy calculations for multiple projects at Kearns Mancini Architects, working on complex projects that push the boundaries of PH design.
She has revolutionized how BIM implements the calculations required for PH certification of projects. The PH industry has been slow to offer solutions to extract data for large-scale buildings, typically implementing intermediary software to co-ordinate between PH calculations and the building model itself. Fisher created a workflow utilizing the same BIM Revit model as the working drawings, thus allowing for a fully iterative process to evaluate PH compliance at all stages of design. This allows the existing model to be programmed for accurate, time-saving data collection, and for all the data to live in one place, being captured at project milestones for quick and efficient analysis. Her process has removed the need for additional software or to transfer geometry to other software to capture data for PH energy calculations.
Emma Cubitt, OAA, MRAIC, LEED AP
Principal, Invizij Architects, Hamilton

Licensed as an architect within the past decade, Emma Cubitt has consistently taken initiatives to develop her skills and professional experience to become an effective leader at Invizij Architects. Her leadership includes becoming a principal at Invizij Architects in May 2019 at the age of 39.
“Emma’s leadership in the broader construction industry is demonstrated not only through her award-winning designs, but also in how she has led our team of architects, consultant engineers, contractors, and clients in understanding and adopting advanced Passive House design and construction standards,” said Bob Prince, AScT., OAA, LEED AP, principal at Invizij Architects and her nominator.
Cubitt’s commitment to her local community is demonstrated by her tireless volunteer efforts to improve the lives of others. She is a founder of the Mustard Seed Co-op, Hamilton’s community-owned grocery store, organizer of the Hill Street Community Garden, and mentor to young people exploring architecture and design as a profession.
Geoff Scott, P.Eng., CAHP
Senior associate, Ojdrovic Engineering, Toronto

Geoff Scott joined Ojdrovic Engineering after graduation, and has since grown into a “great asset in the areas of design, heritage structural engineering, and construction planning.” He leads Ojdrovic’s team of engineers and technologists and co-ordinates projects on heritage-designated buildings, such as the Restoration of Fort Frederick and the Province House Conservation Project in Charlottetown, P.E.I.
Away from the office, Scott enjoys curling and sailing, but has also taken the time to give back to the community. He is a member of the organizing committee for both the Project Sunshine and AMICI camping charities, which provide programming for children with financial and medical needs.
“Geoff’s attention to detail, well-organized approach to work, awareness of responsibility of a structural engineer, and kind and friendly demeanour have gained him recognition of peers, co-workers, and clients,” describes his nominator Nebojsa Ojdrovic, PhD, P.Eng., principal, Ojdrovic Engineering. “Geoff is clearly a leader of tomorrow in our industry and it is with great pleasure that I nominate him for this award.”
Deborah Bryne, C.Eng., MIEI, CPHD, LEED AP
COO, Kearns Mancini Architects, Toronto

Deborah Bryne is a passionate and highly skilled design project manager and sustainable building advocate dedicated to constructing better, cleaner, and healthier buildings. In both of her roles as COO of Kearns Mancini Architects and chair of Passive House Canada, Bryne has demonstrated a history of working effectively in the architecture, planning, real estate, and construction industries.
At Kearns Mancini Architects, Bryne’s experience in Passive House (PH) design has influenced many projects. As compliance architect for the University of Toronto Student Residence project, Bryne proved the requirements of student living could be met in a PH project. She is also spearheading the details and design of the YWCA Hamilton Women’s Residence. This project is also at the forefront of technological PH detailing, as Bryne’s team worked in tandem with a concrete prefabrication system to create the first PH concrete prefabricated envelope in Canada.
As the chair of Passive House Canada, Bryne acts as an advocate and advisor to promote PH principles to many governing bodies, institutions, and corporations.

Kevin Pickwick, P.Eng., AScT., CCCA, LEED AP, CEA
Associate, RJC Engineers, 
Victoria, B.C.

“Kevin leads by example. He is an advocate for lifelong learning.  Kevin has used his experience and knowledge to mentor several of his direct reports and colleagues to achieve their own registrations. He spends innumerable hours contributing to the industry via active involvement at critical levels,” says his nominator Terry Bergen, CTech, CCCA, LEED AP, CPHC, managing principal, RJC Engineers. 
Kevin Pickwick is the president of the British Columbia Building Envelope Council (BCBEC). Pickwick has demonstrated leadership by working with industry partners to verify the thermal and structural performance of cladding products and associated materials. Recently, Pickwick was appointed to the technical subcommittee of the Canadian Standards Association (CSA) Z5010, Thermal Bridging Calculation Methodology. Pickwick is also a supporter of several RJC charitable activities. He has been a supporter and rider in the Ride to Conquer Cancer, a leader in VICA U40 construction projects, and a supporter of United Way fundraising activities.
Emerging Leader Award – Leadership

Emerging Leader Award – Initiative
Emerging Leader Award – Technology Advancement

Emerging Leader Award – Teamwork
Photo © Mathieu Deshayes
Emerging Leader Award – Technology Advancement

Emerging Leader Award – Teamwork
Emerging Leader Award – Community Contribution
Emerging Leader Award – Industry Contribution

Emerging Leader Award – Community Contribution
Emerging Leader Award – Industry Contribution

message from the president
message du président
A Time for Reflection

Moment propice à la réflexion
A
s the holiday season approaches and another year draws to a close, I hope you take this opportunity to reflect on where you have been this past year, and where you plan or hope to be in 2020. Too often, we get caught up in our day-to-day lives, and fail to reflect on where we have been and where we are going. We stay in unsatisfying jobs or positions and relationships that drain our energy, or continually encounter situations or circumstances that leave us stressed, tired, and unhappy. Being on autopilot without reflection can lead to doing the same things over and over again and expecting different results—this was Einstein’s definition of insanity. Self-reflection has many positive effects when implemented on a regular basis. Here are some benefits of self-reflection.

Provides perspective
Self-reflection allows you to look at and understand things from a different perspective and/or an alternate point of view. When you allow yourself to step back and be open to different perspectives on things, you gain new understanding and/or ways of perceiving the issue at hand.

Improved self-awareness
Self-awareness is essential to understanding yourself on a deeper level. What do you value? What do you hold in high regard? What brings you fulfillment? What makes you happy? If you want to get really clear on how you feel about something or what your core values are, follow up with why?

Emotional intelligence
With self-reflection you are able to see yourself using multiple lenses. Different perspectives will aid in tapping into your emotions and understanding them from various vantage points. In paying attention to your thoughts and beliefs, you can better understand your emotions and reactions to a particular situation. Emotional intelligence is the ability to identify emotions in you and others, and choosing an appropriate response.
As this is the season for gifts and giving, may you consider giving yourself the gift of time for self-reflection, relaxation, and rejuvenation throughout the year. I wish you all the best this holiday season. Here’s to a healthy, happy, and prosperous 2020! 
À
 l’approche de la saison des Fêtes et à la fin prochaine d’une autre année, je souhaite que vous profitiez de l’occasion pour réfléchir à savoir où vous étiez pendant la dernière année, et où vous prévoyez, ou espérez, vous retrouver en 2020. Nous sommes trop souvent pris par nos vies quotidiennes et nous n’arrivons pas à réfléchir à notre cheminement passé, et futur. Nous restons dans des emplois, des postes et des rapports insatisfaisants qui drainent nos énergies, ou alors nous sommes constamment face à des situations ou circonstances qui nous laissent stressés, fatigués et malheureux. Le pilotage automatique sans réflexion peut nous amener à répéter sans cesse les mêmes choses en espérant des résultats différents, affirmait Einstein—c’est là sa définition de la démence. L’autoréflexion présente de nombreux avantages positifs si elle est mise en œuvre régulièrement. Voici quelques avantages de l’autoréflexion.

Perspective
L’autoréflexion permet de voir et de comprendre des choses d’un point de vue différent et/ou alternatif. En prenant du recul et en s’ouvrant à des perspectives différentes, nous avons une nouvelle compréhension et/ou de nouveaux moyens de percevoir les enjeux.

Meilleure conscience de soi
La conscience de soi est essentielle pour se comprendre soi-même plus profondément. À quoi accordez-vous de la valeur? Que tenez-vous en plus haute estime? Qu’est-ce qui vous satisfait? Qu’est-ce qui vous rend heureux? Si vous voulez être vraiment transparent quant à ce que vous ressentez sur une chose ou ce que sont vos valeurs fondamentales, faites un suivi avec la question pourquoi?

Intelligence émotionnelle
Grâce à l’autoréflexion, vous utilisez plusieurs lentilles. Des perspectives différentes vous aideront à exploiter vos émotions et à les comprendre selon différentes époques. En portant attention à vos réflexions et vos croyances, vous pouvez mieux comprendre vos émotions et réactions face à une situation particulière. L’intelligence émotionnelle consiste en la capacité d’identifier les émotions chez vous-même et chez les autres, et à choisir une réponse adéquate.
Puisque c’est la saison des cadeaux et des dons, songez à vous donner le cadeau du temps d’autoréflexion, de détente et de renouvellement pendant toute l’année. Je vous offre à tous mes meilleurs vœux pour le temps des Fêtes. Souhaitons-nous santé, bonheur et prospérité pour l’année 2020! 
Greg Hofsted