What Is A Tension Fabric Building?
A tension fabric building is a steel-framed structure covered with an engineered membrane material. Fabric buildings can range from ten feet wide to more than two hundred feet wide. A key characteristic of tension fabric buildings is that, unlike conventional structures, they do not require intermediate posts or supports for large clear span widths. Tension fabric buildings can be specified to include options like interior membrane liners, insulation, HVAC, lighting, fans, vents, and a variety of personnel and overhead doors.
History of fabric buildings
The basic structural concepts behind tension fabric buildings have been understood to some degree for thousands of years. Humans developed this understanding intuitively through their use of tents. Remains of tent structures have been carbon-dated back to around 40,000 B.C. Many early civilizations, like the Bedouins, Berbers, Moors, and Native Americans, passed down tried and true methods to build a variety of increasingly complex tent structures. In the mid-1800’s engineers like Vladimir Shukov pioneered new structural engineering innovations that allowed for the practical calculation of stresses and deformations of tensile structures, shells, and membranes. In the 1890s, Shukov designed the first steel-supported tensile membrane roof structures that would become the starting point for modern tension fabric buildings. Continuous development and improvements throughout the 20th century by innovators like Frei Otto led to the current generation of tension fabric buildings we see today.
Who uses fabric buildings?
A diverse mix of individuals and industries regularly choose fabric buildings for their quick installation, cost-effectiveness, natural ambient light, and versatility. For public works and road maintenance departments, fabric buildings have replaced pole buildings and conventional salt sheds as their choice for road salt and sand storage. Other industries that store and process commodities, like fertilizer producers, recyclers, cement producers, composters, potash producers, and mining, use fabric buildings to manage large quantities of material cost-effectively. Individuals choose fabric buildings for garages, workshops, boat storage, and RV storage.
What are fabric buildings used for?
Some common tension fabric building uses are for recreational space, workspace, and storage. People involved in recreational activities like tennis, soccer, and horseback riding choose fabric buildings for the large open space, high ceilings, and weather predictability they offer. For storage, people are usually looking for the largest space they can afford to protect materials they want to preserve.
Truss profiles and composition
While there are many truss profile variations available, two of the most used profiles are the arch and the gable. Arch truss profiles are the most popular choice for small to medium width buildings, and gable trusses excel for wider buildings. The majority of tension fabric buildings are built with a series of steel trusses connected with purlins and braced with cables. Most fabric building manufacturers fabricate structures with steel trusses consisting of a welded framework of chords and struts, although a few manufacturers utilize steel I-beam frames instead of trusses.
Steel finishing is an important consideration of fabric building design. Several steel finishing options are available, including pre-galvanized steel, primer, powder coating, and hot-dip galvanizing. For smaller structures, some companies prefer pre-galvanized steel tubing, a cost-effective choice that comes with disadvantages. For larger structures and corrosive environments, hot-dip galvanizing offers the best protection and product longevity.
There are several membrane options available for fabric buildings, most of them based on a woven scrim with different coatings. For many years HDPE (High Density Polyethylene) has been the most widely used membrane due to its balance of performance and cost. Other membrane options include PVC (Polyvinyl Chloride) coated polyester, or for specific uses, a porous membrane like an HDPE (High Density Polyethylene) shade fabric.
There are several foundation options available for use with tension fabric buildings. While cost is usually a factor, the first consideration in selecting a foundation is whether the installation will be a temporary or permanent structure.
Temporary tension fabric building foundations will usually be less expensive to install but are limited in the size of buildings they will support and will not match permanent foundations’ longevity. Temporary foundations do not normally require heavy machinery or a large workforce to install. Often a couple of people with common tools can prepare a temporary fabric building foundation. Temporary building foundations, most of which do not include a subfloor, work well for agriculture buildings, riding arenas, and work areas. Many temporary building foundations will leave little or no environmental footprint behind once the building is removed.
Permanent foundations, often chosen because they feature a solid, durable floor as part of the foundation, are well suited for sand and salt storage buildings, fertilizer storage buildings, water treatment plants, recycling facilities, and aircraft hangars.
Learn more about fabric building foundations in this LEARN article.
The installation of a tension fabric building is a relatively quick process considering the size of the structures. In fact, fabric buildings are often installed in less than half the time it takes for similar-sized steel or conventional buildings. Fabric buildings have two inherent advantages that speed up the process of completing construction – offsite construction and simple assembly.
These structures consist of prefabricated components produced in a climate-controlled offsite construction facility. Unlike on-site construction, no time is lost to weather delays. Additionally, while the manufacturing facility is fabricating the structural components, a site crew can simultaneously prepare the construction site and foundation.
Despite the large size of fabric structures, their assembly process is deceptively easy. Truss segments bolt together with simple connections. Once components reach the prepared construction site, installation is usually measured in days instead of weeks or months.
GNB Learn is an information resource for general contractors, developers, engineers, architects, and individuals interested in tension fabric buildings. Learn articles are written by our installation, engineering, and project management staff based on lessons they’ve learned from working in the field.