Blooming across North America and Europe like huge, white poppies, increasing numbers of tent-like structures are becoming a hot option for indoor riding arenas. The buildings, known generally as “tensioned membrane structures,” combine high-tech layered fabrics, clever engineering and either aluminum or steel frameworks. Between their high-ceilinged, airy interiors and the softly filtered sunlight that washes throughout, they provide what owners and riders describe as a “cathedral” effect.
You may have seen these not in an equestrian setting, but more likely as warehousing, emergency shelters or even a casino or shopping center. Priced at less than similarly sized steel structures, and with a lifespan pushing 30 years, the new cathedrals of sport are finding more and more satisfied users who don’t feel that permanence is their top priority.
But what are they like inside, you ask? Can you give a clinic in there and have the clients hear the instructor? That seems to be their strongest point—the positive impression they leave on those who’ve ridden in them. Judy Gustafson, owner of the Chimney Hill Equestrian Center in Salem, Va., said that from the start, “I loved the lighting, we don’t need to turn on the lights until it’s pitch black outside, and the acoustics are great—an instructor can speak normally in there and be heard by everyone.”
Her arena, built by Cover-All Building Systems of Saskatchewan, Canada, is a truss arch-shaped building similar to a half-barrel, 72 feet wide and 220 feet long, with a 5-foot masonry wall supporting the metal arches and skin. It provides a pleasant, year-round shelter for the Chimney Hill dressage horses, with five or six horses per day working inside.
Natural Horsemanship professional Pat Parelli has adopted the fabric arena approach as well. “When I looked at metal-covered arenas to erect at our International Study Center in Pagosa Springs, Colo., I got really frustrated,” he says. “When I was inside any of them, I felt like I was in a tin can; they were noisy and when it rained it sounded like you were inside a metal drum. And if there’s any type of humidity, it felt like it was raining inside the building because the condensation would ‘sweat’ in the interior,” he says.
“I chose the Cover-All because it’s cooler in the summer and warmer in the winter, just the opposite of metal buildings. When it rains, there’s a nice soft, murmuring sound, like rain on a tent. With the white covering, it’s pretty much always light inside. And because we photograph so many events and articles for magazines, our photographer is really happy with the white background the Cover-All provides. I liked the Cover-All we had for several years so much that I bought another one that was much bigger (110 feet by 160 feet), and in September we’re going to have seating for 2,500 people inside our ‘Titan’ Cover-All at our Savvy Conference.”
The Cover-All Titan building series is shaped more like a conventional building with a 30-degree roof slope and comes in clear-span widths from 30 to 200 feet.
Under the Tent
What is a stressed-membrane structure, really? It’s a family of structure designs, ranging from a thick, layered polyester “skin” pulled tight over a frame, to the Sprung Instant Structures company’s series of aluminum arched ribs integrally connected by modular, architectural membrane panels. In the same way that your camping dome tent holds itself off you and the ground even on a windy cliff, and that a bubble retains its shape, these structures are isometrically stable, pulling and pushing against themselves.
How big can these apparently ephemeral, but strong, structures be? They range from small garage or shavings-shelter dimensions to 250 feet wide or more, and unlimited lengths. One, created by Sprung, houses NASA’s space shuttle on off days. Clearly, your lesson program could probably be accommodated without too much trouble.
Kit Strang of Strang Ranch in Carbondale, Colo., installed a fabric arena this summer, and says, “Cost-wise, it was much less than a metal structure. Preparing the site, providing power and water to the building and finishing the interior will cost as much as the structure itself. We hope to get everything done, including some landscaping, for under $175,000.”
So how much for the building itself??Cover-It, Inc., of West Haven, Conn., offers a vinyl-fabric riding arena 72 feet wide, 150 feet long and 28 feet high for about $45,000.
Drew Elder, a representative for Cover-All buildings, says, “In most cases, our buildings are lower in cost, but it is not just because of the materials. . . . Cover-All buildings require a less extensive foundation, the install time is more efficient, and the requirements for mechanical components such as artificial lighting and air conditioning are not nearly as extensive.”
Given great, firm footing, some manufacturers’ fabric models can be brought in without the need for footings. Some merely require drilled, spaced “earth anchors.” Larger, heavier models may call for a full foundation, depending on your building codes. Take away foundation costs, and you have a far more efficient building project.
The key to economical facilities, of course, is to choose a construction that needs little special engineering, something off-the-shelf. Fortunately, an arena large enough for jumping or running barrels is not a terribly complex item. Whether it is a large Titan arena as Parelli’s, or a classic, arch-style building as at Chimney Hill, the basic concept is clean and elegant.
For example, the Polygon Series from Universal Fabric Structures, Inc. of Quakertown, Pa., resembles a rather flattened gambrel-roof barn, and is sold in 92-foot, 105-foot or 118-foot widths, using prefabricated aluminum box beams and high-tensile, stretched polyvinylchloride (PVC) coated polyester fabric panels.
Sprung Instant Structures’ models top out at 43 feet high for a 100-foot-wide model, supported by aluminum I-beams. The Sprung structures, recently in the news as part of the World Trade Center’s ground zero relief effort complex, seldom require foundations, and can be disassembled and transported, given enough hands to do the job.
As sizes increase, building shapes and materials change, which can affect the cost. For example, with bigger structures, galvanized steel replaces aluminum for the structural support.
Many of the companies listed here (see sidebar p. 31) do offer rental or leasing programs which might be an attractive option for some operations.
Weathering the Elements
Can these structures stand up to wind and snow? Would the ceiling be sagging on a soggy winter day? Nope, that’s the beauty of the slippery fabric and curved structure—these buildings don’t lend themselves to accumulating a snow load.
Fabric domes do create some odd effects, however. Canadian rider and equine nutritionist Karen Briggs, having ridden in several fabric structures, noted that “when snow and ice melt and slide down the fabric, it makes a loud zipping sound that has sent many a spooky critter shooting from one end of the arena to the other.”
One rider described the sound of snow sliding off the roof of a Sprung arena as “Something like a long, long strip of Velcro® opening. The noise goes on for quite some time. Most of the horses . . . got used to the noise and eventually ignored it, but it is a very distinctive sound and something you don’t hear in a conventional steel arena.”
Arena owner Judy Gustafson agrees. She found that with wet Virginia snow, at least, the sound was not too disturbing to her horses, and they all got used to it fairly rapidly.
Wind-wise, the structures are designed to be very safe. They have no flat sail-like sides to catch the force of the wind and be torn asunder. Instead, wind tends to wrap around the aerodynamic curves and passes by, although some rustling and flapping sounds are par for the course when that’s happening. The Harnois Megadome, from Greenhouse Supply, is 80 feet wide, can withstand a 46 pound-per-square foot snow load and an 86 mile-per-hour wind load. The Cover-It arena is rated for wind loads up to 110 miles per hour and snow loads of 60 pounds per square foot. Most of the others are similar.
More Cool Stuff
Tensioned membrane structures have other advantages beyond cost:?they are both warmer in winter and cooler in summer than standard metal or wood structures. The winter “meatlocker” effect, especially notable if you’re the frozen-footed instructor with no warm horse beneath you, just doesn’t happen.
Briggs says that the fabric buildings are “a lot warmer in the winter.” Gustafson agrees. She notes that in the one year since her arena went up, she has had no footing freeze and hasn’t felt the need for a heater. And in the summer, the breezes from one end door across to the other have been most pleasant.
“I went to a trainer’s metal arena in Pennsylvania in the summer, and it was an oven; the thermometer on the wall was above 120 degrees even with the doors open,” she says. Coming home to her own sunlit, naturally climate-controlled facility was a joy.
A Moving Experience
Some of these buildings are designed to be transportable. But in the case of those with foundations, this would seem a daunting task. And taking them down for summer, back up for winter? Seems like a challenge, but considering that these structures can be installed in a week or less, only the cost of labor would slow you down if a move seemed essential. Universal’s Polygon model and the Sprung Structures are the easiest to put up and take down.
Most companies offer 12- to 25-year warranties on their exterior fabric. At Greenhouse Supply, fabrics are prorated over 10 to 15 years depending on the choice of cover. The darker covers have more UV resistance, therefore a longer warranty.
The warranties for the structural aluminum or steel support range up to 30 years (for the Sprung Instant Structures’ aluminum frames). As a practical matter, many of the frames will last in excess of 30 years.
The Fine Print
Insuring these buildings has not been a problem so far, especially as the fabrics can be fire-retardant coated and are warrantied.
Building permits may be easier to obtain than for traditional structures. Elder of Cover-All says that when it comes to acquiring building permits, “A fabric membrane structure enjoys an advantage over conventional construction, as building codes allow for an approved fabric to be equivalent to non-combustible construction.” And in some agriculturally zoned areas, such as Durham County, N.C., no building permits are required for agriculturally-related facilities.
These structures may not immediately add as much to your property value as a conventional building since they’re not designed to be permanent (especially the models without foundations). But by the same token, depending on your local laws, you may not have to pay taxes on them.
Elder notes, “I have heard in one situation that a Cover-All commercial customer was paying taxes amounting to 10 percent of those for a comparable conventional constructed building, as a result of the capital cost being significantly lower than conventional construction. The comparison in annual cost savings in taxes was more than $6,000.”
The only way to figure out if one of these new fabric arenas might be just the ticket for your barn is to research the potential advantages and disadvantages particular to your situation, such as cost, site preparation, taxes and aesthetics. The look of these new structures does not exactly conjure up a traditional red barn set among the trees, but the advantages of better light and more space may make these new structures look pretty darned good in the end.
For More Information
Cover-All: 800-268-3768; www.coverall.net
Cover-It: 800-252-6297; www.coverit.com
Greenhouse Supply: 800-696-8511; www.agrotech.com
Sprung Instant Structures: 800-528-9899; www.sprung.com
Universal Fabric Structures: 800-634-8368; www.ufsinc.com
Allsite Structure Rentals: 888-599-5112, https://allsitestructures.com