Rigid-frame fabric buildings offer a high-quality solution for budget-minded projects.
By Shannon Humbert and Eric Donnay
We live in a world where spending power can create some pretty wide disparities. Gawdy mansions and luxury cars exist because somebody can afford them, even if most of us are quite comfortable and happy living in a family-friendly house and driving a reliable, modestly-priced vehicle.
Similar gulfs in wealth are evident in the sports facility market, where professional franchises and the top major college athletic programs can rely on massive television contracts and booster funds to construct any type of building they deem necessary, with every bell and whistle included to play games, train athletes, or attract recruits.
In most of the sporting world, there exists a similar goal of designing the best athletic facility money can buy – it’s just that the amount of money to actually work with is much lower. For the majority of universities, schools, communities, or recreation clubs in the process of procuring a new athletic facility, finding the best value is paramount.
Cost-Effective Sports Architecture
The conversation for many entities naturally begins with traditional brick-and-mortar buildings. This makes sense, since it’s the construction option with which most people are familiar, and there are usually very few question marks about how such a building would look and function.
In reality, though, not everyone is in a financial position to spend money on traditional construction. Many organizations have instead turned toward more affordable alternatives, such as tension fabric buildings. However, even this building category alone offers some drastic differences when it comes to engineering, quality, and longevity.
First of all, it’s important to establish how fabric structure styles have evolved in the past decade. More than 10 years ago, Legacy Building Solutions introduced rigid-frame, structural steel engineering to fabric building design. Prior to this development, fabric structures were mostly built with web truss framing, a system still prevalent among many suppliers today.
By utilizing I-beam frames, fabric buildings instantly achieved more universal credibility. From an engineering perspective, rigid-frame design was a known and proven method. From an end user viewpoint, it essentially provided a conventional approach to building construction, just with fabric material as a more cost-effective cladding for the roof and sidewalls.
Besides inspiring more structural confidence, rigid-frame design also opened up a new world of possibilities by providing much more design flexibility, allowing users to customize their fabric buildings to the precise dimensions necessary for the sports or activities taking place inside.
When web-truss fabric buildings first became available to the athletics and recreation market – and even to this day – they were typically supplied in standard, pre-engineered sizes. Therefore, if a certain length and width were needed, for example, customers would have no choice but to go up to the nearest available standard size. Another feature of this building style is its curved frames, which can create unusable space along the sidewalls. The end result is that users often have to find ways to fit their building, rather than designing the building to fit their actual needs.
With structural steel design, purchasers can start out with a clean sheet and develop a custom building plan from the beginning of the process. If the plan calls for basketball or volleyball to be played near a sidewall, the wall and roof slope can be built high enough to accommodate that activity. If the plan calls for tennis courts, the structure can be designed to USTA guidelines for building peak height and allow for the necessary space around each court.
Ultimately, the rigid-frame design provides the ability to value-engineer a fabric building. By having their exact specifications met, users can get the space they truly need without paying for excess space or construction materials.
Of course, fieldhouses and practice facilities for sports like football and soccer typically do require a lot of space, another area where rigid-frame fabric buildings prove cost-effective. The inherent strength of these I-beam structures, combined with lightweight fabric cladding, allows for long clear span roofs with no support beams.
Old-school fabric structures lack the true engineering integrity necessary for really long spans. Brick-and-mortar buildings are structurally sound, but the larger the building needs to be, the greater the price difference between traditional construction and rigid-frame fabric buildings, which can be installed at a fraction of the cost.
Another construction option that has long been popular, due to its price tag, is steel buildings. While steel-sheeted structures can help fill a certain niche in the industry, their cost-saving advantage gradually disappears as the building dimensions become larger. And no matter what size structure is required, steel buildings tend to fail the aesthetics test, generally offering poor lighting and acoustics.
By contrast, the interior environment inside a fabric building offers a softer feel, better acoustics with less echo, and much improved lighting due to the reflective properties of the fabric material. People who’ve never set foot inside a fabric sports structure often comment that the atmosphere exceeds their expectations.
While having an attractive venue is certainly beneficial to those using or visiting the building, engineers and architects will also take notice that the same materials used to create that welcoming atmosphere are actually serving another purpose in helping to meet building codes.
For projects where state or local energy codes must be met, a rigid-frame design allows building suppliers to easily apply insulation – typically with R values ranging from R-19 to R-30 – along the interior of the structure. The insulation is secured and then covered with a fabric liner that is actually the same type of fabric used for the exterior cladding.
Polyvinyl chloride (PVC) has the been the primary fabric of choice for sports facilities for many years because of its durability. The fact that users can select different colors of fabric to match their team, school or organizational branding is also a selling point for fabric in general. Legacy Building Solutions offers a newer fabric called ExxoTec™ PVC that delivers more durability and a longer life expectancy, due to the added layers of primer and lacquer around its high-strength woven fabric.
To install the fabric, Legacy relies on its patented fabric attachment system that uses half-inch diameter bolts to clamp a keder rail to the top flange of the structural steel frame. Fabric panels are then slid through the keder channel to connect to each beam. This process allows fabric panels to be pulled into place with the properly calculated horizontal and vertical tensions.
Wider fabric panels are used for the interior than the exterior of the building, but otherwise the process is the same both outside and inside. With the interior liner tightly secured, maintenance concerns for the fabric cladding itself are practically nonexistent.
Behind the Scenes
For many industries, the I-beams in a fabric building are left exposed and may require some kind of treatment to protect the steel. Since the structural frames in most fabric-cladded sports facilities are encapsulated by insulation and liners, typically a primer coating is all that needed to treat the beams.
That said, building users in coastal locations or who experience high humidity conditions due to their facility application – such as a swimming pool – could consider epoxy paint for I-beam treatment to protect against corrosion. Because the steel beams are permanently out of view, some users might choose this option purely for the peace of mind of knowing that the structural frame is well protected.
It is worth noting that the rigid frame building design allows for effective passive ventilation within the walls. Ridge and soffit vents use the natural movement of warm airs to help remove moisture from the insulation cavity, another key piece in meeting building codes for a given environment.
Because of the airtight nature of a lined fabric building, air flow is very important, and passive ventilation alone is not enough for most athletic structures. Users will need some sort of mechanical means to at least move air, if not also heat or condition it. Often this means the inclusion of fans or an HVAC system suspended from the building frame above.
For a rigid-frame design, supporting hanging loads like HVAC, fire suppression systems and lighting isn’t difficult, although it does need to be considered in the original design. Engineers use finite element analysis software to calculate the stresses for each individual I-beam, rather than over-engineering the entire structure and adding unnecessary cost.
Likewise, many sports facilities need to accommodate items such as scoreboards, video platforms, court dividers and netting. Some will even need to add mezzanines for spectator seating. By working with the customer to account for every potential collateral load, building designers can simply modify the rigid frame to add the necessary strength for those loads.
While project managers may be primarily focused on getting the most bang for the buck from a fabric building, of course it’s also common to need to appease certain stakeholders with additional flourishes, such as exterior facades containing brick or stonework. While these elements will add cost, the straight sidewalls of a rigid-frame structure do make it possible to easily include these types of touches.
Another possibility with I-beam design is adding a fabric-clad addition to the gabled end of an existing structure. Designers need to consider snow loads and rain runoff for the original building and new addition, among other compatibility factors, but for situations where expansion is a more cost-effective solution than new construction, it often can be done.
Built Fast, Built Right
Rigid-frame fabric buildings can also be completed in far less time from start to finish than traditional brick-and-mortar buildings. While the time to build the framework is similar for a fabric building and a metal-clad structure, fabric panels can be applied in one-third the time needed to screw down metal siding.
A big reason for the overall reduction in fabric building lead time is that companies like Legacy are full-service suppliers who can handle every step in the process from start to finish. By employing their own design engineers, manufacturing fabric panels and I-beams in their own facilities, and sending their own in-house professional installation crews to every jobsite, these companies can ensure full quality control and constantly keep projects moving, without any of the unexpected delays experienced by those relying on outside vendors.
All things considered, tension fabric structures offer exceptional value for sports venues large and small. From proven structural integrity to a high level of interior finish and craftsmanship, rigid-frame fabric buildings make it possible for any entity to obtain a facility they can be extremely proud of, without breaking the bank.