TEXTILES.ORG
A comprehensive understanding of engineered tents provides peace of mind.
By Pamela Mills-Senn
As cities and municipalities grow increasingly risk averse and safety aware, the demand for engineered tents has surged.
“The market is definitely strong,” says Jeff McInnes, North American sales manager for Delray Beach, Fla.-based HTS-USA/Hocker, a manufacturer of clearspan structures. “No one wants to be responsible for deploying a structure that wasn’t designed to offer a certain degree of safety for guests.”
The upside for manufacturers and for those who sell or rent engineered tents is that business is good and promises to get even better as regulations governing temporary structures become more stringent. The downside is that as tent suppliers attempt to attract sales, the label “engineered” is getting tossed about, says Brad Kramer, CEO of Creative Tent International Inc. The company, located in Lake Havasu City, Ariz., designs, manufactures and sells tension fabric structures.
“The word has gotten a lot of use lately,” Kramer says. “It has become almost a marketing term, and I get concerned when ‘engineered’ is treated as a marketing term. People need to look past that label and dig deeper.”
Define ‘engineered’
What qualifies a tent or temporary structure as engineered? The term is commonly used to describe a product that has been pre-engineered to meet a specific code, explains Alex Kouzmanoff, vice president of Aztec Tents, a manufacturer of temporary tents and semi-permanent fabric structures, located in Torrance, Calif.
“In most cases, a generalized approach is taken to meet the specific building code requirements for the widest range of applications,” he says. “In many cases, the specific requirements in hurricane-prone areas, on high-exposure locations near large bodies of water, and even from city to city, can be different from the design criteria, and thus the engineered design may not meet the heightened requirements for these installation locations.”
McInnes says they start with a baseline, using International Building Code (IBC) 2009 or 2012. The design is modified higher if necessary to accommodate any site-specific requirements such as wind or snow loads, soil conditions or other exposure considerations. Kramer uses IBC 2012 and American Society of Civil Engineers (ASCE) 7-10 codes as the standards for his designs. End users renting or purchasing an engineered tent should ask what codes it conforms to, he advises.
“Some engineered tents are engineered to much earlier codes,” he says. “But the codes change about every five or six years. There were big changes in 2012. Now they’re applying more permanent building codes to these structures.”
Jim Reyen, national sales and marketing manager for tent manufacturer Eureka!, in Binghamton, N.Y., says the description can be applied to any wind-rated tent that may or may not meet a specific code. He admits this is confusing.
“You could have a tent that was engineered—designed by an engineer—that doesn’t have a specific wind rating or meet a specific code as well,” Reyen says. “But if you hear a member of the industry say ‘engineered tent’ it usually means one that’s wind-rated and certified to meet a 70-mph sustained wind and a 90-mph three-second gust of wind.”
Additionally, engineered tents typically come with documentation, such as an engineer package, stamped by an engineer verifying that the structure complies with the relevant codes.
Unsafe assumptions
Engineered structures confer safety advantages, but their benefits can be negated by end user complacency. One risky assumption is that if a tent is engineered, it’s right for every application, Kouzmanoff says.
“Nothing could be further from the truth,” he says. “The installation of a tent on the ground in an urban environment and the installation of the same tent on the roof of a third-floor parking garage are totally different and thus so would be the engineering.”
Consequently, says Kouzmanoff, understanding the site conditions where the structure is to be installed is essential, because the tent may require modification of the engineering to assure maximum safety.
Weather is another consideration, says Chad Struthers, vice president of Warner Shelter Systems Ltd., a designer, manufacturer and distributor of engineered tents, located in Calgary, Alberta, Canada. For example, the company’s clearspans are rated for snow; their high-peak Marquee tents aren’t and are best used during non-winter months. The Marquee structures can be used in winter, he says, but a close watch must be kept on the weather.
End users should never underestimate the importance of appropriate installation. An engineered structure can’t compensate for carelessness when setting it up, Struthers says.
“Engineered tents can be stamped, but all of that means nothing if the end user doesn’t install them properly,” he says. “Everything depends on the setup.”
Scott Sutherland, president of Olympic Tent, a Tacoma, Wash.-based manufacturer, gets concerned over improper anchoring, something he says is common.
“This typically involves using fewer stakes than are needed, or misplacement of the outguy stakes, or failing to understand the loading capacity of the ground in a certain location,” Sutherland says. “Also, there are some rental companies that use water barrels in lieu of stakes without fully understanding the wind-load limitations of the barrels.”
Additionally, all the components comprising an engineered tent work together, creating a complete structure. Substituting components or making other alterations can result in structural failure, Reyen says.
Avoiding surprises
Because codes and permitting for these structures are getting stricter, buyers need to beware of tents that risk failing an inspection and not getting permitted in their jurisdiction.
“It’s very much planning and logistics,” Struthers says. “On our drawings we call attention to the importance of site conditions, and rental companies should be conducting site inspections and asking questions about what the tent is being set up on.”
It may also be necessary to have a professional engineer package with the stamped seal of the state where the structure will be erected, says McInnes. (These packages contain the site-specific requirements the customer must provide to the municipality in which it is working.)
Such packages have become increasingly important because more municipalities are requesting them, says Kramer. “For about 80 percent of the tents we sell, the engineering packages are requested with the structure,” he says. “Also, we’re getting calls from people who bought tents three years ago for which they now need the engineering package.”
Because installation may be denied without documentation, it’s a good idea to ask for this from manufacturers, Reyen says. “I’ve heard of many stories from rental companies that have been promised an engineered tent but found it very hard to obtain the proper documents for it.”
These engineering documents contain a “considerable amount of information,” Sutherland cautions, which can be confusing for the uninitiated. He advises that it can be helpful for rental companies to review this document “carefully and thoroughly” with the manufacturer.
Probably the best protection against unwanted surprises is focusing on quality and durability rather than price alone, says Struthers.
“If you’re an owner of a rental company, do your due diligence,” he advises. “It’s not about shopping on the Internet looking for the cheapest products. At the end of the day, it does not come down to price.”