Long-Span Structures: Critical Factors for a Successful Project
By definition, everything Legacy builds is a long-span structure. Long span is defined by the width of the building and the span of the roof frame across the entire structure. Anything more than 20 meters is considered a long span, but for Legacy, that’s on the low side. These wide open structures are also known as clear span or free span buildings.
A key component of our buildings is that there aren’t central column supports, which gives our customers unobstructed floor space.
Long-span fabric buildings are for people (or organizations or horses) who need a lot of space. Examples include sports facilities, warehouses, hangars, equestrian arenas, and bulk storage.
Professional Design and Installation
Due to the nature of long-span construction, the framing members and trusses require special care for installation. These structures may need bracing during craning and construction to keep the materials true. Before constructing a long-span structure, ensure the contractor and building installation crews have experience working with buildings of similar size.
“The style of the building gives us more useable space and a more robust frame than the other options we considered. Construction was so easy – the crews showed up and were completely self-contained. The entire project was boom – done – easy.”
--Kelly Fisher, Training & Exercise Coordinator and Field Operations Specialist for Hennepin County Emergency Management
Legacy, for example, uses our own crews for most installations, so their training and experience make them experts in long-span buildings.
A licensed engineer should also be consulted on the structure's planning and design stages. The engineer will ensure that the building is structurally sound and meets local building codes. Because the roof of the structure is not supported by interior columns, the structure must be designed to withstand snow, wind, rain, and seismic movement without excessive deflection.
“It was designed so trucks could enter and exit in a safe and controlled manner, and this configuration has already saved us time and money. Installation of the infrastructure and building itself was quick and efficient. The end users of the building, in particular, are very excited about the advantages afforded by the new building.”
--Steve McAvoy, INDOT
For sports facilities, the appearance of a long-span structure inside is as important as the structure's functionality. In these cases, an architect is typically part of the team designing the building.
Materials Used in Long-Span Building Construction
Certain construction materials are better suited for long-span structures. Long-span structures must be made of materials light enough not to require interior supports yet sturdy enough to withstand the pressures placed on the structure.
- Steel is a common building material for long-span structures. Steel is strong and relatively lightweight, so it is suitable for the building frame and/or the outside cladding. Legacy was an innovator when it shifted to solid steel frames a few years back. It allows us to create long-span spaces up to 300 feet wide.
- Wood, particularly wooden trusses, may be used for smaller long-span buildings. Long wooden beams are more expensive and harder to locate, making wood less common for larger buildings.
- Structural fabric is a common choice for long-span structures because fabric structures are lightweight, inexpensive, and can quickly cover large surfaces. Legacy uses a PVC-based fabric called Exxotec™ that is unique to our buildings. It’s tough, beautiful, and has a 25-year pro-rated warranty (for the 28 oz. fabric).
In addition to strong frames and tough exterior cladding, Legacy fully customizes every building we install. There are no off-the-shelf buildings because we believe every customer has unique requirements. Our design team isn’t interested in shoe-horning you into a building that only partially meets your needs. Contact Legacy if you want the whole package: a long-span building that is state-of-the-art in terms of engineering and functionality.