Tension fabric structures: setting a new standard for facility construction

by arslan_ahmed | December 4, 2023 11:00 am

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By Ben Fox and Ellie Fox

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In the case of tension fabric buildings, there exists the unique potential for miscommunication while even just considering whether a fabric structure is the right architectural choice in the first place. This breakdown is not so much about a failure to communicate, however, but more of terminology simply meaning different things to different people based on experiences.

For many, the term “fabric building” carries negative connotations of being a cheap or temporary option. For others, the exact same words are 100 per cent positive, as this group understands that with the right approach, fabric cladding brings a multitude of potential benefits to the table for water treatment facilities, recreational complexes, aircraft hangars, waste-to-energy plants, bulk salt/sand storage, and numerous other applications.

Revolutionary engineering

It is common with any product or service that has come a long way to describe that journey as its evolution. While evolution is a fair term to illustrate the past decade of the fabric building industry, what happened in the years before is perhaps better described as a revolution—a paradigm shift that fundamentally changed how fabric buildings were conceived and perceived.

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Prior to 2010, most fabric structures were erected with hollow-tube web truss frames, and users were limited to whatever pre-defined dimension offerings had been established by different manufacturers. This often forced customers into a dilemma: settle for a cramped space or purchase more building than necessary. Such a decision was never ideal, but in certain industries with only the most basic facility needs, it was considered satisfactory.

What happened next changed everything for fabric buildings. Leading manufacturers developed a method for applying fabric to a structural-steel rigid frame that used solid I-beams instead of web truss framing. This shift instantly advanced the credibility of fabric buildings within the engineering community. It was not merely a step along an evolutionary path; it was a revolution of such magnitude that it registered more like the creation of a wholly new product category. Rigid-frame design had opened a completely uncharted road for fabric structures.

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With I-beam frame engineering, all buildings get a clean sheet design from the beginning. Using finite element analysis software, engineers could now customize the building to meet individual user requirements. In other words, fabric structure suppliers had begun employing conventional construction methods, while still being able to offer the benefits of a fabric membrane solution, which can include natural daylighting, cost-effectiveness, and energy efficiency.

Constant innovation

Supported by proven engineering, structural frame designs empower users with the flexibility to implement wide clear spans or taller height clearances. I-beams can also be individually optimized in the design process to account for suspended loads on the structure, such as mezzanines, conveyors, light fixtures, HVAC, and fire suppression systems.

Customized designs and larger dimensions were only the beginning. Engineers continued their push to innovate fabric building beyond what most had considered possible. With I-beam design in play, fabric buildings could be fitted up with other construction materials.

Suppliers began to work with project subcontractors to place fabric building framing members alongside metal or steel stud and gypsum board partition build-outs. Materials such as brick and stone are commonly implemented for facades along fabric exterior walls. I-beam tension fabric structures can also accommodate overhead and roll-up doors, personnel doors, and even windows.

With greater capabilities came increasing opportunities to tackle more complex jobs. In many cases, the primary structure itself is not the most intricate aspect of the project. Fabric building manufacturers have taken on a variety of new challenges. In many cases, the main structure may not be the most complex part of the job. Notable projects have seen manufacturers install a fabric structure over existing wastewater plant equipment, provide a new fabric-cladded addition to a conventional brick-and-mortar building, and supply multiple buildings at varying elevations that needed to be properly terrain-matched to accommodate an accessibility ramp and elevator in a connecting foyer.

Optimization has become paramount to fabric building design. The days of fabric structures coming in pre-engineered, off-the-shelf size offerings share little resemblance to today’s quality-driven approach of providing the optimal solution to the client.

Fabric advancement

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While the introduction of the I-beam frame was the most dramatic revolution in fabric buildings, fabric cladding itself has also seen some remarkable improvements. Polyethylene (PE) has been the most widely used fabric in Canada and elsewhere for as long as fabric structures have existed. Polyvinyl chloride (PVC) was the more expensive alternative, usually reserved for higher end project types where its added strength and longevity was a requirement.

Several years ago, innovations in a new PVC brought the price tag of this material more closely in line with PE fabrics, even though the product had actually been improved at the same time to make it an even more attractive option than PE.

Standard PE fabric has three layers: a scrim layer with the fabric weave and two coating layers on the top and bottom to seal in the fabric. The newer PVC material is constructed of seven layers: high-strength woven fabric in the middle, primer layers applied to the base fabric, top-coat layers on both sides to give the product its shape, then a final lacquer layer on both the top and bottom to seal the fabric with a smooth finish. Weathering tests have indicated this advanced PVC fabric will retain more than twice the tensile strength of a standard PE fabric, giving it many more years of long-term durability.

It is worth noting fabric’s usefulness means different things to different users. In some markets, such as commodity storage, aviation, and agriculture, architects use white fabric roofing because of its translucency, allowing natural sunlight to help illuminate the interior during daytime hours. This can cut down on artificial lighting needs. Fabric is also adept at keeping the interior environment warmer in the winter months and cooler in the summer months.

In other instances, such as athletic facilities, schools, and event centres, it is more desirable to have an insulated building for a consistent and controlled indoor temperature. Insulation is covered with a fabric liner, which offers the benefit of a bright and beautiful interior look and feel for the activities taking place inside.

Single-source quality

Much like any construction contracting situation, different fabric building manufacturers bring different strengths to the table. As noted earlier, not all “fabric buildings” can necessarily be considered part of the same product category. It is important to discern the details when looking at the quality and completeness being offered, just as it would be with the purchase of any product.

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Another significant step that leading fabric structure suppliers have taken to distinguish themselves is vertical integration—bringing all their design and manufacturing processes in-house and being the primary point of contact for all project communication.

It is common in the tension fabric building market to outsource the fabrication of the structure’s metal frame. However, some manufacturers have invested in their own on-site facilities to produce the I-beams for their building projects. With certified welding inspectors as part of staff, these companies help ensure a higher level of quality control (QC), while avoiding the occasional surprise of receiving out-of-spec framing components from an outside source.

As an extension of manufacturing the I-beams, some companies now have their own paint shops to treat them. This capability has allowed manufacturers to offer premium coatings such as epoxy paint at an affordable cost, gradually replacing hot-dip galvanizing as the fabric building industry’s preferred method for protecting steel frames and components from corrosion.

The change is significant. The thin layer of zinc added during galvanizing comes with a limited service life, as that layer basically exists to sacrifice itself until it is eaten away, leaving the frame unprotected when it reaches that point. Epoxy paint, by contrast, creates a true barrier between corrosive elements and the steel beam, helping to prevent corrosion from ever touching the steel.

Aluminum framing systems, which are naturally corrosion-resistant, are another alternative in the fabric building industry. However, depending on the application and design goals with respect to structure size and frame strength, they are not always a compatible project solution.

Some companies have taken fabric production in-house as well. This allows internal personnel to fully handle another major component of the building, ensuring a controlled environment for the fabric cladding to be prepped and manufactured to the proper specifications.

To further ensure all in-house services are achieving the desired standards, leading manufacturers also go through an ongoing audit process to maintain International Organization for Standardization (ISO) certification and Canadian Standards Association (CSA) A660 certification. In particular, fabric buildings in Canada must be code compliant with CSA S367, covering all air-, cable-, and frame-supported membrane structures.

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Fabric pays off

A prominent differentiator for fabric buildings compared to brick-and-mortar construction is the speed of installation. Long-term schedules with a conventional build can be shortened to a timeframe of just months with a tension fabric building, however, there are key differences within the
fabric realm.

Some suppliers require customers to hire subcontractors to erect the structure. Other companies have their own trained crews, to ensure proper horizontal and vertical tensioning of the fabric, among many other critical details.

The pace at which projects are completed is especially notable in today’s economic landscape. Those who are hesitant to move forward with building projects because of higher interest rates may find that fabric improves the financial picture, simply by allowing them to become fully operational in a building much faster; in turn, they can quickly start realizing their return on investment (ROI).

After considering the innovative design approaches and material upgrades that have occurred and seeing how widely accepted tension fabric structures have become across so many markets, one realizes it is not hyperbole to consider modern fabric buildings to be a revolutionary facility solution.

Authors

[7] Ben Fox is the founder and president of Legacy Building Solutions. Along with two-plus decades of fabric building experience, he notably created the process for applying fabric cladding to rigid steel frames. He can be reached at bfox@legacybuildingsolutions.com.

[8]Ellie Fox is the chief operating officer of Legacy Building Solutions. With 10 years of experience in the fabric building industry, she oversees operations throughout the company. She can be reached via email at
efox@legacybuildingsolutions.com.

Source URL: https://www.constructioncanada.net/tension-fabric-structures-setting-a-new-standard-for-facility-construction/

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