Structures for every site
The tight economy, increased focus on sustainability and technical innovations are combining to make air, tension and frame-supported structures strong players in the sports and recreation marketplace. The large, open spaces they provide create multiple options for usage with both reduced costs and a shorter installation time than brick and mortar structures.
This interior view of a frame-supported Universal Fabric Structures installation shows the combination of translucent membrane at the building peak and supplemental lighting.
PHOTO COURTESY OF UNIVERSAL FABRIC STRUCTURES.
Typically, the first question a potential customer asks is what size building they need for their primary use. Then they inquire about financing options and how quickly they can get delivery if they place an order right away. Making the right match for these types of structures is much more complex than that.
Suppliers note their compliance with a plethora of regulations including the International Building Code (IBC). It addresses such issues as structural stability, access for the disabled, fire prevention, and structural components such as electrical, mechanical and plumbing. Regulatory agencies of the states, counties and municipalities develop additional standards or codes of their own, which may or may not vary for structures considered seasonal and those considered permanent. Local environmental factors such as wind, snow load and potential seismic activity all impact the design of these structures, too.
Suppliers point out their ability to serve as a resource for every step of the process, from initial design to regulatory compliance. They encourage potential customers to “start with the dream” and tap into their expertise to achieve it.
Erik Lindstrom is director of marketing for Yeadon Fabric Domes, Inc. (www.yeadondomes.com), a supplier of air-supported recreational structures. Lindstrom says, “Air-supported structures are the polar opposite of brick and mortar in that we work from the top down, engineering against uplift. For safety and security, the total spectrum of site-specific environmental conditions must be factored into the engineering process.”
Air-supported structures require positive air pressure throughout the entire structure to remain inflated, so the design must include air lock entrances and exits. There’s a primary inflation unit and a backup unit not tied to an electrical power source to maintain pressurization.
According to Lindstrom, air-supported structures 125 feet or larger need cables to anchor them. He says, “The concrete with an aluminum channel for the cable is designed based on the specifications of the dome. We don’t do the concrete work or provide the floor surface, but [we] handle everything else – doors, the air movement system, heating or cooling unit, inflation units and lights.”
The cost varies depending on the size and options selected. Lindstrom says, “Typically, our fabric dome structures range from one-quarter to one-third the cost per square foot of comparable-sized brick and mortar structures.”
Yeadon’s most recent U.S. project was the University of Minnesota student recreation center completed late in 2011. One of their largest structures is in Anchorage, Alaska. It’s a 300-by-600-foot multisport facility that includes a 400-meter track.
Seasonal coverage with air-supported structures is a way to maximize recreational space and generate revenue through rental fees, so many facilities are opting to purchase them for use on existing synthetic fields. Lindstrom says, “The turf can be pulled back to do the concrete work and then reinstalled. From that point, putting up the dome is just like a new installation.”
Yeadon also offers maintenance or repair service and seasonal take down and reinstallation. “Depending on the size of the dome, the takedown typically takes one or two days,” says Lindstrom. Off-season storage is another consideration. Yeadon plans to offer storage for a fee to its midwestern customers by 2013.
This Yeadon Fabric Domes air-supported structure in Anchorage, Alaska, is a multisport facility.
PHOTO COURTESY OF YEADON FABRIC DOMES INC.
New to the sports market
Market Solutions International, (MSi, www.marketsolutionsintl.com), is the authorized representative for Dynamic Air Shelters (www.dynamicairshelters.com) which builds some of the largest “Air Beam” structures in the world. One example is approximately 12 stories high, 300 feet wide and 500 feet long. MSi’s Tom Kaptian says, “Air beam technology utilizes columns (also called beams) that are filled with air to an operating pressure of 1.5 PSI and then covered. The airtight fabrication ensures structural integrity, even in the event of a power failure. The blower for each series of columns only runs about 10 minutes a day to maintain that PSI. An air beam structure large enough to cover a FIFA regulation soccer field would only require eight blowers.”
Installation of a Dynamic Air Shelters air beam structure is underway, showing partial beam inflation.
PHOTO COURTESY OF MSI DYNAMIC AIR SHELTERS.
According to Kaptian, the company’s air beam structures have been used for 15 years in industrial and military applications from the deserts in the Middle East to the Arctic. They are resistant to wind forces from 80 mph to as high as a category 3 hurricane (130 mph).
He says, “We’re now entering the sports and recreation market, with our initial target existing synthetic turf fields. Dynamic Air Shelters are custom manufactured to the client’s specifications and sizing from a range of PVC-coated, high-strength materials. The translucent outer skin allows natural light and is brandable with client logo or other advertising. Our warranty is for 15 years; life expectancy is 20 to 25 years.”
Like air-supported and frame-supported structures, air beam structures can include electrical, lighting, HVAC and air filtration systems.
Kaptian says, “The air beam structures provide ultra-portability. Even the very large units require only two to three hours to inflate. As stand-alone, temporary structures, they do not require foundations and have no need for pegging or tie-downs, so after takedown nothing is left behind. A facility owner could use the structure to cover a synthetic field for cold weather use, and then move it to any other site for short or long-term venue opportunities the remainder of the year.”
Frame-supported tension membrane structures may be pre-engineered or custom designed utilizing either a steel or aluminum support frame in varying strengths and sizes, with multiple options available for the membrane covering. These options vary depending on the potential usage, site-specific situations and the supplier.
While many perceive frame-supported fabric structures as temporary, they’re actually permanent or semi-permanent. The metal components have an unlimited life span. Though warranties on the membranes vary according to the supplier, most have an anticipated life span of 20 to 25 years. These structures are also 100 percent relocatable if other usage is needed for a site or a land-lease expires.
The width of these structures is the limiting factor. There are no limits on length. The wider the structure, the more closely spaced the trusses must be for stability. In regions where structures must withstand 130 to 140 mph sustained wind, truss spacing could go from 15 to 10-foot spacing, thus increasing the resistance by 50 percent. In both cases, the tightened spacing increases the cost per square foot.
Operational costs are another important issue. Depending on the type of structure, its long-term or seasonal use, regional climate and site-specific weather conditions, both heating and air conditioning may be desired. Thus, insulation and R-values must be considered. While insulation may range from an R7 to R30, with changes in energy codes and the sustainability movement, more of the frame-supported structures are going with the higher R30 insulation.
Suppliers are encouraging customers to think multisport, multiuse for frame-supported structures, viewing them – like today’s stadiums – as revenue generators.
Consider the possibilities
Jay Sabia is a truss arch specialist for Clear- Span Fabric Structures (www.clearspan.com). He says, “We provide frame-supported buildings in every size from a small equipment storage unit to a multisport facility 300 feet wide by unlimited length. We use triple galvanized steel for most of our structures and offer several options in the fabric type in either standard or custom colors or patterns. We also can use a different polycarbonate material at the peak of the building to maximize natural light. The cover’s translucent and reflective qualities offer further energy savings by providing indoor temperature stability. Superior ventilation options, such as roll-up sides and wall vents, are available. ClearSpan’s warranty is 15 years.”
ClearSpan prefers total project management during installation for better overall flow and shorter construction time. They have companies set up to handle the concrete work, synthetic turf and HVAC. Sabia says, “ClearSpan developed a hardware system with a series of pipes and strapping that make it easier and more affordable to insulate our frame-supported structures either during the initial installation or at any point after that.”
“Norseman Structures (www.norsemanstructures.com) uses superior steel manufacturing methods including precise, laser-cut trusses and advanced welding techniques to ensure the highest quality framework,” says Robin Taylor, director of marketing. “The steel ranges from 14 to 7 gauge, dependent on the region. All components, from screws to cables to trusses, are engineered for structural integrity. We ensure fabric cover quality by performing continuous fabric strength testing and employing only certified equipment operators. Optional liners may be added to regulate air temperature and lower energy costs for heated facilities. Additional customized options include flooring, accessories, lighting, door styles and placement, or attachments to existing buildings.”
Michael Belisle is business director for sports and recreation for Universal Fabric Structures, Inc. (UFS, www.usfinc.com). He says, “We offer both aluminum beams and steel truss frame structures. Both carry a 25-year warranty on the frame. We work only with the larger structures, generally 80 feet to 350 feet wide. We do our own in-house engineering and can handle any custom design. While we have standard fabric colors, we’ve never had a request for a specialty color that we couldn’t match. We can do most any pattern or design as well. Though we will install the HVAC and lighting if requested, frequently the general contractor will handle that part of the project as well as the concrete work and floor surfacing.”
One project UFS recently completed is for Sanford Health in Fargo, N.D. Belisle says, “It’s an aluminum beam structure, 95 feet wide by 258 feet long with two curved ends that give it an oval shape. It has an inner liner, R30 insulation, HVAC and lighting. They’re using it as a rehab facility for athletes, with a running track, artificial turf and basketball courts.”
Phil Sprung, president of Sprung Instant Structures, Inc. (www.sprung.com), says, “We purchase, rather than manufacture, the membranes to tap into the continual upgrades in technology. Our niche is 90 to 120 days from conception to completion once the structure is permitted. That compares to one to two years for a conventional building.”
Sprung structures range from 30 feet wide to 200 feet wide in 10-foot increments. Sprung says, “We expand the length in 15-foot modules, with no limitations. The height runs a little under one-half the width, with a 160-foot-wide structure 55 feet high. The arch shape is designed with a 26-degree pitch, which allows the building to shed snow to the perimeter while providing the aerodynamics to withstand the wind. We provide a 20-year warranty on the membrane.”
Sprung structures often start with Johns Manville fiberglass insulation, followed by the aluminum substructure, then reflective foil backing and interior membrane, and finally the exterior architectural membrane. It reduces climate-control costs and improves acoustics.
Many Sprung structures include a green solution to increase natural light. Sprung says, “Translucent membrane is an option for the peak of the structure at no extra cost. It’s the same grade and type of material, just a translucent form of it, heat-sealed in place. We used it in our own 65,000-square-foot office and for 300 days of the year we have no need for supplemental lighting. It’s just as effective in sports structures.”
The end of the membrane life cycle doesn’t make these structures obsolete. Sprung says, “A new membrane can be installed over the old one for approximately the cost of a new roof for a conventional building.”
According to Belisle, “The cost to replace the fabric is roughly 20 percent of the original cost of the structure.”
With all this and more innovations on the horizon, check out all the options when considering a structure.
The author is a contributing editor for SportsField Management.