Potential builds for fabrics in construction
Versatile and lightweight, architectural fabrics are finding new niches in construction.
Specialty Fabrics Review | May 2010
By Barb Ernster
Decades of experimentation about how best to use fabric in building design and construction has a lot more interest and growing potential for what fabric can do, driven by a desire for greener, cleaner, lighter, higher performing and sustainable structures. “Architects are still trying to struggle with how to deal with the impermanent nature of textiles, or general lack of knowledge of what they can and can’t do. I think we’re on the cusp of something that hasn’t yet unfolded,” says Blaine Brownell, assistant professor at the University of Minnesota School of Architecture.
Architectural fabric is taking several directions—one as an exterior ‘envelope’ that adds a high profile, visible and dramatic effect. An example, says Brownell, is the new Copenhagen Concert Hall in Denmark, noted for its striking resemblance to glass, yet it’s really a translucent textile façade made of Ferrari’s Stamisol® FT 381 stretched taut over a steel beam frame. In daytime, vague outlines of people and space are visible inside; at night, the fabric is a projection screen for moving video images of concert performers, color and light that enliven the building.
Fabric is also being used as a building ‘skin,’ blending visible and performance features, such as thermal control, water and dirt repellency, light transmission, acoustical absorption, sustainability and disaster protection. The National Aquatics Center (aka The Water Cube), built for the 2008 Olympic Games in Beijing, was designed with ETFE fluoropolymer film that allows 98 percent light transmission, is water repellent, and has insulating properties to control interior temperature and humidity.
“Architects for years have said they basically want GORE-TEX® for buildings,” says Brownell. “They want light and air transmission, but control of moisture.” They’re also looking at the potential for renewable energy with fabric, the ability to integrate thin film photovoltaic into a fabric skin.
Others are experimenting with disaster relief structures, incorporating fabric into concrete for stability and waterproof membranes into walls. Brownell is fascinated by the idea that fabrics can be a source of building security. Zetix™, for example, is a blast defense fabric made by Auxetix Ltd., Tiverton, England, that is designed to protect against multiple explosive incidents. It can also be used for hurricane or military defense applications.
The ‘green’ response
As the industry grows greener, Saint-Gobain Performance Plastics in Wayne, N.J., is working at finding a way to attach photovoltaic cells on its PTFE-coated fiberglass membranes (SHEERFILL®), a product the company has been manufacturing for several applications since 1973. It started selling ETFE for new construction because of its greater translucency and malleable properties. Energy savings and sustainability are driving the need for smarter new—and retrofitted—stadium roofs, and PTFE membrane only has an insulation value of R-1, according to Marcel Dery, global sales manager.
A new layered composite called Tensotherm™ by Birdair Inc., Amherst, N.Y., is helping to solve the issue. It uses Nanogel® aerogel, a half-inch thick, feather-light insulation layer that traps air to prevent heat loss and solar heat gain, and allows daylight harvesting by transmitting and diffusing natural light. A layer of aerogel sandwiched between two layers of PTFE, rather than the standard one- to two-foot space required for fiberglass insulation, can boost R value to 12.
“This is an answer to something that we’ve been looking for for a long time. Being able to control R is a big deal,” says Dery. “It responds to energy reduction concerns. All we do is replace the roof; nothing else has to be replaced. It makes retrofitting very easy.”
Elevating R value
New European energy and building codes also drove AeroLite Fabric Pty. Ltd., a division of Fabritecture LLC based in New South Wales, Australia, to create a three-layer fabric composite called AeroLite™ to address the need for greater thermal efficiency without sacrificing the thin profile necessary for freeform design and translucency in its fabric structures
“A lot of our applications are for fully enclosed structures that require mechanical cooling or heating, and building codes in Australia and elsewhere are now requiring continuous form insulation to increase thermal efficiency in such structures,” says Dave Gullis, managing director of Fabritecture. “Using AeroLite, we are able to help our clients reduce running costs of the finished structures while at the same time reducing the greenhouse gas emissions and the overall carbon footprint of these structures. This is the future of sustainable building.”
A thin layer of Aerogels® SpaceLoft® blanket sandwiched between two layers of PTFE or PVC helps boost the R value and can insulate very thin spaces. The thermal efficiency of AeroLite is six times greater than a single-skin fabric system, Gullis says, and two-and-a-half times greater than a double-layer fabric system. Initial studies have shown it can reduce energy consumption from heating or cooling the interior of a fabric structure by 30 to 70 percent, depending on the climate. It is being used in sports stadiums, recreational facilities, water parks and ‘green’ shopping centers around the world. AeroLite development manager Lisa Leslie says it is also being used in thermal awnings and blinds to provide a lower cost option to window replacement for retrofits of old buildings that must comply with new energy codes.
“There is a lot of interest coming in from all over the world; buildings that have been around for years need to retrofit in a cost-effective way,” says Leslie, adding that she is also exploring opportunities with companies that are creating tents and large-scale structures for emergency relief or other uses in extreme environments.
More function in layers
Architects in the U.S. are driven less by government incentives or regulatory codes and more by voluntary sustainability programs like LEED certification, says Chris Macneal, architect and senior associate at KieranTimberlake in Philadelphia, Pa. Layered fabric composites, where each layer has a specific task, can serve many functions in building design and construction
“There is currently a lot of development in certain nonwoven, sheet membrane materials and nonfabric films that are designed to serve specific functions within the layered construction of building envelopes,” says Macneal. “There is much ongoing development of fabrics that have design, structural properties or properties for managing flows of heat, air and moisture. It’s an area where there’s a lot of foment and research right now, and one that has bearing on construction assemblies. We recently started working with stretched fabric ceiling systems which combine acoustical and light transmission properties in the ceiling finish.”
More architects and builders are incorporating acoustics as an integral feature of a building or room’s intended environment, says Bill Mordecai, North American sales and marketing manager at Freudenberg Industrial Nonwovens in Durham, N.C. The company has seen growth in applications for its Soundtex® panels used in a wide variety of building complexes, airports and sports facilities to reduce noise and produce clearer acoustics. The product’s ultra thin profile can replace a thick mineral mat, which also has its advantages. Lighter weight composites with greater performance are in higher demand as builders are looking for material savings and waste reduction. “If you can make a component easy to transport and install, that has an economic value,” says Mordecai.
J. Miller Canvas Inc. in Santa Ana, Calif., is working with a number of architectural firms to create cutting edge designs with fabrics that conserve on space, waste and energy
“It’s definitely about how to better utilize space—more open work environments where people can collaborate and work together,” says owner Jim Miller. “There are things you can do with fabric that you can’t do with hard surfaces. It’s exciting to have something that starts from nothing and come up with these totally different ways of using fabrics.”
The company built a large retractable fabric classroom at Virginia Commonwealth University in Richmond, Va. With the flip of a switch, a series of motors and micro switches raise the entire room up and fold it against the ceiling to open the full space for special events. The room is made of a canvas exterior and sound-absorbing interior material for privacy.
Energy savings is a growing issue for many clients, says Miller. Older buildings are at a disadvantage cost-wise, but fabric is providing new solutions. J. Miller Canvas worked with XTEN Architecture in Los Angeles, Calif., to modernize a four-story building that was incurring high cooling costs from too much sun exposure in its many windows. Using Ferrari’s Stamisol 371 vinyl-coated polyester, a translucent mesh fabric stretched over a rigid frame that was mounted away from windows, it created an airflow space, while repelling solar heat and glare. The project cut the building’s cooling costs by $4,500 a month.
“It not only took care of the heat problem, but modernized the building for a fraction of the cost of major structural changes to the building,” says Miller. “The owner was floored. He couldn’t believe how much it saved on air conditioning costs, and it gave the building a sleek modern look all at the same time.”
Fabrics in building design and construction—greener, cleaner, lighter, cheaper, longer or better performing functions—are part of the discussion and continue to be developed. Miller, for one, is convinced that “we’re just at the beginning.”