Tension fabric buildings are constructed using a Rigid Frame which can consist of timber, steel , rigid plastic, or Aluminum and a sturdy fabric outer membrane . Once the frame is erected in place, the fabric cover is stretched over the frame. The fabric cover is tensioned to provide the stable structural support of the building. The fabric is tensioned using multiple methods varying by manufacturer, creating a tight fitting cover membrane. The benefits of tension fabric buildings compared to traditional structures can be: Lower operational costs, energy savings, naturally bright, quick installation, ability to re-locate building, flexible foundation design options,and corrosion resistance. Unlike conventional or metal clad buildings, tension fabric buildings can be more economically relocated.
In some political (building code) jurisdictions, tension fabric buildings may qualify as temporary structures which benefit from a shorter capital depreciation period, relative to a permanent structure, for tax purposes. Buildings classified as temporary structures may have significant limitations on occupancy, applied load and fire safety considerations and period of installation.
Tension fabric buildings have gained popularity over the last few decades in many industries including the following applications: hay and feed storage, horse riding arenas, commercial, manufacturing, warehousing, sand and salt storage for road maintenance departments, environmental management, aviation, airplane hangars, marine, government, military and emergency shelters.
Building sizes are usually standardized by the nature of being a pre-engineered building. Some manufacturers produce tension fabric buildings spanning up to 300 feet wide and to almost any length. Buildings can be designed to be portable, mounted on wheels or other rolling crane-type designs fitted to the baseplates, or lifting in modules by overhead cranes. Exceptional projects require special design considerations which should be communicated to the manufacturer at the quote proposal stage or in project tender specifications.
Industrial strength fabric, some of which can have life expectancies of 20–30 years, have been used for many applications. Fabric's life expectancy is affected by local environmental factors (e.g. sunlight, temperature, wind, air quality) and occupancy conditions (e.g. humidity, chemical vapours). The current structural membranes available are made of PVC or Polyethylene. Some fabrics are sufficiently translucent to allow sunlight to pass through, creating a naturally lit environment inside the building. Fabric selection influences project capital cost and maintenance. Material decision factors should consider the project budget, nature of the project and the required durability.
While common application of tension fabric buildings are for temporary use, they are not exempt from regulatory requirements including compliance with building codes, occupancy classifications, aesthetics and building permits. Fabric tension buildings are required to meet the same Building Code safety requirements and applicable design standards as any other structure. Professional architectural and engineering consultants should be engaged to design the project to ensure proper compliance to all safety and code issues.
Tension fabric buildings may have assembly details that make them amenable to disassembly and reassembly at a new location. This is different from other forms of pre-engineered buildings: Metal clad buildings require sealants that make disassembly difficult and fastener penetrations that cannot be easily duplicated (e.g. new screw in existing hole) in reassembly if all reconstruction tolerances are not exactly duplicated at the new location. However, in all cases, code compliance and structural loads at the new location must be considered for occupant safety.
Tension fabric building manufacturers accept the responsibility to design some or all elements of the building: strength and stability of the structural system, cladding (fabric), thermal/air/vapor retarding membranes and service limit conditions (e.g. deflection under load) as specified by the project designers and within the context of applicable building codes and design standards. Tension fabric buildings are designed with CAD (computer-aided design) software for the customization of the building and to ensure it will meet load and service expectations (e.g. wind/snow/collateral/seismic loads and deflection/vibration service requirements).
Structural load, architectural and performance or service requirements will influence building pricing. It is important to be able to assess variations in proposals to ensure that prices reflect similar product offerings. Consultants who specialize in tension fabric building projects should be engaged to specify and review supplier submissions.
Tension Fabric Buildings are commonly referred to as: Fabric Structures, Fabric Tension Buildings, Cover-All Buildings, Fabric Buildings, Hoop Buildings, Quonset Structures, Sport Halls, Tents and Bubbles. Note: Cover-All is a manufacturer name which, through regional commercial success, is generally suggestive of specific forms of manufactured building products. Cover-All ceased business in 2010[1] after several highly publicized large structural failures[2][3][4] and lawsuits[5]. Quonset huts, corrugated metal arch buildings, achieved common recognition due to their popular use by the U.S. Military services during World War II but the form is easily duplicated with tension fabric buildings.
Project Professionals and Manufacturer Designed Buildings
The project Architect, sometimes called the Architect of Record, is typically responsible for aspects such as aesthetic, dimensional, occupant comfort and fire safety. When a pre-engineered building is selected for a project, the Architect accepts conditions inherent in the manufacturer's product offerings for aspects such as materials, colours, structural form, dimensional modularity, etc. Despite the existence of the manufacturer's standard assembly details, the Architect remains responsible to ensure that the manufacturer's product and assembly is consistent with the building code requriements (e.g. continuity of air/vapour retarders, insulation, rain screen; size and location of exits; fire rated assemblies) and occupant/owner expectations.
Many jurisdictions recognize the distinction between the project engineer, sometimes called the Engineer of Record, and the manufacturer's employee or subcontract engineer, sometimes called a specialty engineer. The principle differences between these two entities on a project are the limits of commercial obligation, professional responsibility and liability.
The structural Engineer of Record is responsible to specify the design parameters for the project (e.g. materials, loads, design standards, service limits) and to ensure that the element and assembly designs by others are consistent in the global context of the finished building.
The specialty engineer is responsible to design only those elements which the manufacturer is commercially obligated to supply (e.g. by contract) and to communicate the assembly procedures, design assumptions and responses, to the extent that the design relies on or affects work by others, to the Engineer of Record - usually described in the manufacturer's erection drawings and assembly manuals. The manufacturer produces an engineered product but does not typically provide engineering services to the project.
In the context described, the Architect and Engineer of Record are the designers of the building and bear ultimate responsibility for the performance of the completed work. A buyer should be aware of the project professional distinctions when developing the project plan.
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