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It’s not uncommon for a new commercial roof to cost $250,000 or more. Typically, the roofing system includes insulation, a cover board, the roofing membrane or waterproofing material and all of the fasteners, adhesives and other accessories such as drains, pipe supports, and the roof’s edge system needed to install the roof, including the roofing contractor’s labor.
The roof edge system is the visible metal trim at the roofline of most commercial, industrial and institutional facilities that outlines the building’s perimeter. While it may not be given much forethought, the roof’s edge system is a critical component of a commercial roofing system. The edge metal serves several purposes including acting as an effective termination and transition between the roofing system and the other building components. More important, it serves as the roof’s first line of defense against wind and water infiltration.
After several major hurricanes in the early 2000s, studies and analysis of roofing damage conducted by the Roofing Industry Committee on Weather Issues (RICOWI) in conjunction with Factory Mutual (FM) and SPRI reported that nearly 60% of damage to roofs was caused by failure at the perimeter. In fact, they reported that of the analyzed roof failures, the vast majority of those were caused by poor workmanship and/or substituted materials. The findings are clear: when the perimeter edge metal fails, the roofing system cannot withstand the associated wind loads and progressively fails as well.
What Does This Mean for FMs?
Facility managers and commercial roofing specifiers need to be adamant about maintaining the edge metal specification when value engineering questions arise. All too often, an engineered edge metal system which has been designed and tested to meet the building code standard, is “substituted” for a product which has not been tested and which may not meet local building code requirements. Such materials are often supplied by the roofing contractor who either bent the metal in their own shop or had it supplied from a local sheet metal supplier.
The International Building Code requires commercial roofs to have an edge system that meets the ANSI/SPRI/FM 4435 ES-1 standard. This standard evaluates edge metal systems based on a variety of factors such as cleat or rail designs, gauge of the metal used, number and placement of fasteners, and profile design, among others. Each design is assigned a performance rating based on the results of the ES-1 testing. The assigned performance ratings are necessary since there are a variety of important factors for a properly designed roof including wind speed, building height, building exposure, and building use.
While locally supplied edge metal may look similar to pre-engineered edge systems, the differences can be staggering. There are relatively few contractors who have been approved for supplying edge metal that meets ANSI/SPRI/FM 4435 ES-1. For those who have been “approved” through the National Roofing Contractors Association programs, it is important to understand that just because a contractor’s edge metal meets certain aspects of the standard does not mean that it meets the minimum performance requirements for your specific building. For example, your building may require an edge metal system that has passed 150PSF through ES-1. It is possible to have a particular edge metal assembly that “meets ES-1” but has only passed 90PSF, which would be inadequate if 150PSF is required for the pressures on your particular roof. It’s important to recognize that “meeting ES-1” isn’t the only piece of the puzzle – it’s not a simple matter of “pass/fail” as the statement “meets ES-1” seems to imply. Furthermore, it is important to understand that just because a contractor or local metal shop has a limited number of profiles that have been tested to ES-1, does not mean that every edge product they make carries the same rating. All products must be tested individually, not just the fabrication facility.
The bottom line is that roof edge systems in the specification are designed to meet the specific load requirements of a particular building and abide by the ANSI/SPRI/FM 4435 ES-1 standard. Facility managers should be very wary of “value engineering” this component of the roof, as it is the roof’s first line of defense.
Jason Hildenbrand is the director of sales for OMG EdgeSystems in Asheville, NC. For more information, please visit www.omgroofing.com.
In the movie Apollo 13 about astronauts trying to return to Earth after an explosion crippled their moon-bound spacecraft, the flight director in Houston says about NASA’s work to get them home safely, “failure is not an option.”
It’s a rallying cry that operators of data centers, hospitals and other “mission critical” facilities live with every day. Simply put, if their facility were to be disrupted in some way, the impact would be catastrophic to human well-being or business operations.
To help ensure that mission critical facilities continue to function 24/7, more facility professionals are using building management systems (BMS). Similar to other FMs, they deploy BMS to help reduce energy consumption but also use the systems to monitor and control essential equipment for which “failure is not an option.”
For example, many healthcare facilities use a BMS to ensure that life-saving equipment operates within tight tolerances. Such is the case at Emerson Hospital in Concord, Massachusetts. The medical center’s radiation-oncology department relies on its BMS to monitor water temperatures in a linear accelerator that generates external beam radiation to treat cancer. If the temperatures go out of spec, the BMS sounds an alarm so that technicians can take corrective action quickly.
Similarly, data center operators rely on BMS to monitor the temperatures throughout their facilities as well as the cleanliness of the electricity going to the servers. Computers are notoriously heat sensitive, so the BMS helps ensure reliable computer uptime by monitoring and controlling temperatures at hundreds of points throughout a data center. Additionally, a well-equipped BMS can monitor the frequency, amplitude and other characteristics of the power going to the servers to ensure they don’t trip off and take down critical enterprise functions.
Choosing a BMS
Building professionals in the mission critical facilities field face numerous choices when specifying a BMS – which vary widely in their capabilities and ease of use. To ensure that the system delivers maximum benefits, one essential feature to look for is software that is human-centered.
As the portal to the BMS, it is crucial that the software makes sense to the facility operators. Cumbersome software results in either untapped potential in the system or costly and time-consuming operator training. By comparison, programs developed using a human-centered design process make it simple for users to figure out how to work with the program.
In a human-centered design, the software developers watch how actual users interact with the system. They measure users’ performance and note areas where they struggle with the software. The developers then reconfigure the program and again test it with actual people. Results can include restructuring menu trees to make them simpler to navigate, revising graphic images to make them easier to interpret and placing icons where people naturally look for them.
The easiest to use BMS software is built with graphical interfaces. Compared to text-based systems, graphical interfaces enable users to readily see the building or campus as a whole and to zoom-in on individual floors, rooms or specific equipment to check its status. Such interfaces also make it easy to program alarms and to change set points for temperature, humidity, and many other factors.
Also, BMS software that relies on the latest edition of HTML (HTML5) can deliver complete user management of trend logs, alarms and schedules via a web browser. As a result, facility professionals can monitor and control building systems from desktop computers, tablets, smartphones or any internet-enabled device – especially handy for those data center professionals who have to hop on a scooter to zip around their massive server farms.
As you consider how to keep your mission critical facility operating at peak performance when “failure is not an option,” recall the astronauts of Apollo 13, who relied on computerized alarms to let them know when CO2 and other environmental factors were out of whack. With a BMS, like them, you’ll be able to help prevent problems or to respond effectively if something goes wrong – and maybe even get your own heroes thank you for a job well done!
Kevin Callahan is a product owner and evangelist for Alerton, Lynwood, Wash., a Honeywell business specializing in building management systems. He has 39 years of experience in the building control technologies field, including control systems design and commissioning, facilities management and user training. Callahan can be contacted at email@example.com.