Advanced Fabric Buildings for Extreme Climates

Rigid frame industrial buildings for mountains, snows, temperature extremes.

This article sponsored by Legacy Building Solutions.

In industrial and commercial applications, a house is rarely a home; in business, it’s the inventory and operations inside that make money. This puts a premium on capex spent on structures. They need to be good value, quick to build and durable enough to protect the products or machinery inside—which may be worth many times the value of the structure itself.

Explosives storage for a mining facility in the Atacama Mountains, Chile. (Image courtesy of Legacy Building Solutions.)

Explosives storage for a mining facility in the Atacama Mountains, Chile. (Image courtesy of Legacy Building Solutions.)

New technologies allow businesses to deploy structures that are quicker to build than traditional brick and mortar, precast or steel panel constructions, yet they are durable enough for high-value operations such as aircraft hangars and manufacturing assembly lines. Minnesota-based Legacy Building Solutions has developed a rigid frame, fabric covered building technology that meets or exceeds building codes and engineering standards both within the U.S. and around the globe.

The key to Legacy’s fabric structures are the rigid steel frames, onto which Legacy’s ExxoTec PVC-based fabric panels are installed. ExxoTec provides better strength and performance characteristics than competing polyethylene fabrics while still being cost competitive. All of Legacy’s steel frames and fabric coverings are custom engineered to the customer’s specifications and manufactured in the company’s 87,835 square foot facility in South Haven, Minnesota.

Unlike the fabric tents that are often seen in industrial areas, fabric buildings from Legacy are designed to survive and thrive in hostile environments. Among other factors, “Legacy has completed all testing requirements to achieve Florida Product Approval, which included extreme wind pressure testing, missile testing and other tests to ensure the Legacy patented fabric attachment system and design could withstand these extreme weather conditions,” said Dwayne Moench, head of engineering at Legacy Building Solutions.

Missile testing is exactly what the name suggests: an attack on the panels to check for punctures and abrasion. The test involves shooting wood 2×4’s at the fabric, in different locations on the tensioned fabric panel. The missile test is completed after the extreme wind pressure testing, which mimics flying debris in high-wind situations such as hurricanes and tornadoes.

High winds and flying debris aren’t the only extreme weather events that need to be considered. “Typically, hail doesn’t do damage to pretty much any of the fabric buildings,” said Nathan Stobbe, general manager at Legacy Building Solutions. “At Legacy, we provide as a standard product a much higher-strength fabric than is the norm in our industry. The reality is that hail typically works on a fabric building like it does on a trampoline: it doesn’t do much damage, and it just bounces off.”

While Legacy’s fabric panels can resist Mother Nature, no conventional industrial building panel can resist man-made strikes such as an impact from an errant fork-lift truck. However, with a fabric panel building, punctures in the fabric can be repaired much more easily and with less cost than a comparable steel building. Replacing steel sheeting is an expensive and time-consuming proposition, often requiring fasteners or welding operations. But Stobbe said that with Legacy buildings, “repairing a fabric structure is a simple matter of welding a new piece of fabric over the damaged area.” If the damage is more extensive than a patch can repair, it’s a simple matter to remove the damaged panel and replace it with a new one.

Mountaintop Explosive Storage

Legacy buildings have appeared on mountains in Chile, in far-Northern Canada and in many other regions subject to extreme weather. Cold is only one of the challenges facing structures in those areas.

For example, a mining storage building at the Lumina Copper mine in Atacama, Chile, is a 3,200 square foot facility that houses explosives. This location is 11,480 feet above sea level and is rated for a seismic Design Category D, which is one of the higher seismic categories. This rating means that buildings in that zone are expected to be able to resist a more severe and destructive ground shaking.

A mining storage building at the Lumina Copper mine in Atacama, Chile, is a 3,200 square foot facility that houses explosives. (Image courtesy of Legacy Building Solutions.)

A mining storage building at the Lumina Copper mine in Atacama, Chile, is a 3,200 square foot facility that houses explosives. (Image courtesy of Legacy Building Solutions.)

“The building in the mountains of Chile is in a mining community and has very high seismic loads. Nearly all buildings in Chile are for designed high seismic loads, but in addition to the seismic load, this building had a 220-pound roof snow load,” said Moench. “The building is situated in very extreme conditions, even compared to what we’re used to seeing here in North America.”

Legacy enjoys unique projects and is especially proud of managing the challenge of constructing the Chilean mountain building.

“Any provider of a building would have a challenge getting that building up there,” said Stobbe. “This would be the benefit of most engineered building systems. What this allows us to do is manufacture that framework in a factory environment, in which you know you have a lot more control.”

“So, for us, we broke that building down into sections that fit into 40-foot containers, so that it could go as ocean freight and be flown directly up to the site and then assembled it on-site.”

The Chilean mountains aren’t the only extreme environments where Legacy is building.

“Right now, we’re building two aircraft hangars in Guam and they are going into an area that has a 195 mile-per-hour wind load, which accounts for potential typhoon loading,” Moench continued. “This is a very extreme wind load that we would normally see only on the Florida coasts.”

“So whether this is accounting for heavy snow loads in the Northern U.S. and mountain regions, the hurricane coasts of the Atlantic Ocean and Caribbean Sea, or the high seismic areas we find in numerous places around the U.S., these all take special design considerations,” Moench added.

Why Choose a Fabric Building

“In California, we have built two large logistics warehouses at the Ontario airport for some of the world’s largest freight logistics companies,” said Stobbe.

The two buildings measure 150 x 376 feet, and 160 x 437 feet, for a total area of 126,320 sq. ft. Both buildings have a 20 psf live load, 110mph wind load, wind exposure rating C and are designed for a Seismic Design Category D. These buildings not only meet local building and environmental regulations, but also the height requirements of the FAA for their location on site. The buildings also feature passive ventilation and are open to the air on one endwall.

Cargo facilities in Ontario, California. (Image courtesy of Legacy Building Solutions.)

Cargo facilities in Ontario, California. (Image courtesy of Legacy Building Solutions.)

“One of the coolest things in that building was the way it combines air freight and workers. They are there packaging product, getting ready to load on planes, unloading it off the planes, loading and unloading into trucks. It’s just a busy beehive of activity in there,” said Stobbe.

A significant benefit of Legacy’s buildings is that fabric, particularly white fabric, allows natural light through. “The white fabric actually reflects the heat that comes from the sun, and also lets natural light into the building,” said Stobbe.

“There were no lights on in the building, yet everyone could see perfectly. Although it was winter, it was 75 to 80 degrees inside. The building was very comfortable. This really magnified the benefits of fabric, which is reflecting heat and letting in natural light, creating a great work environment.” The clean look of the interior and exterior of these buildings is an additional positive aspect of using fabric, Stobbe added.

Fabric being airtight is another benefit to using it as a cladding material. “If you go into one of our insulated athletic facilities, we have a fabric liner that goes inside the building, which is a very good vapor barrier.  Heat loss through leakage is the number one heat loss issue in metal buildings.  The air-tight liner eliminates much of this heat loss.” 

Importantly, the fabric cladding on a building will not corrode. Over time, steel corrodes in corrosive environments, such as salt storage, fertilizer storage and marine applications. Corrosion can happen in just a few years, and once corrosion begins, it is nearly impossible to stop. Controlling corrosion can be expensive, involving tight humidity control, expensive coatings and structural repairs.

Fabric roof and liner panels avoid these issues. “Fabric is not impacted in any way by corrosive elements, and so if you go around the country, you find that there are a lot of fabric buildings that are used in corrosive environments,” said Stobbe.

Trust the Fabric Building Experts

No matter what extreme environment and weather a building needs to withstand, Legacy can help design a custom fabric building to suit. The process starts with a meeting with Legacy engineers to discuss the customer’s building needs.

This would include discussion of environmental and weather factors the building will have to withstand, as well as conventional details such as the building dimensions and height requirements.

The number one reason to choose Legacy for your fabric building is the proven engineering on Legacy structures, said Stobbe. “Legacy basically took the best part of the metal building industry, which is the frame, and the best part of the fabric building industry, which is the fabric, and we merged those two together.”

“And so, what you get at Legacy is a proven engineering and manufacturing system, which is accepted around the globe. An engineer can understand and recognize how the system works, they can understand the engineering that goes into it, and as a client you can feel confident that your system is properly engineered.”

To learn more about fabric buildings or to talk to a Legacy expert, visit the Legacy Building Solutions website.

 

Written by

James Anderton

Jim Anderton is the Director of Content for ENGINEERING.com. Mr. Anderton was formerly editor of Canadian Metalworking Magazine and has contributed to a wide range of print and on-line publications, including Design Engineering, Canadian Plastics, Service Station and Garage Management, Autovision, and the National Post. He also brings prior industry experience in quality and part design for a Tier One automotive supplier.