What is a Tensile Fabric Structure?

What is a Tensile Fabric Structure?

Tensile (or tension) fabric structure: A structure that is characterised by a tensioning of the membrane system (typically with wire or cable) to provide the critical structural support to the structure.

It can hold many forms, although it is generally based on two basic building blocks: The Saddle and The Cone. This creates dramatic and structural architectural works, offering a wide variety of free form design and roof structures.

The tensioning of the fabric eliminates any creases in the fabric and creates the strength for the material to withstand any severe weather and potential damage.

When to use a Tensile Fabric Structure? 

Tensile fabric structures can be used in a variety of situations. They use less material than traditional structures and as a result, they weigh less and are easier to transport. They are flexible and can be specifically tailored to meet your requirements and provide shade or shelter. In addition to the required practicality elements, tensile fabric structures are a showpiece feature that offer an impressive focal point.

 

Where to use a Tensile Fabric Structure? 

  • When you need a showpiece element that stands out and is different from conventional buildings. This can be as a signature urban object or a building icon.
  • When you need a wide span or column free span. Tensile fabric structures can span unsupported lengths of up to 150 feet and tensile steel cable nets with fabric can easily span twice that amount. Air structures can span even longer distances with column free structures up to thousands of feet.
  • When your building has to move from one location to another during the lifespan of your facility, such as temporary schools, travelling exhibits, etc.
  • When you need a prefab modular building. Metal frame with tensioned fabric panels are the most cost effective modular frame buildings available today.
  • As lightweight additions to existing or conventions buildings, tensile structures can act as canopies, skylights, covered walkways, shading systems or atrium roofs.

 

Can any shape be created?

In a broad answer yes, however there are rules and some expectations.  

As previously mentioned, tensile fabric structures are based on two basic building blocks of tensile structures. However, this is not to say that they are not versatile. The beauty of a tensile fabric structure is the ability to design and create them around your specific requirements.

Every canopy uses the curves and principles of either the Saddle or the Cone, or combines elements of both. The Saddle is a hyperbolic paraboloid which means that it is a surface made by two high points and two low points. The geometry of the surface is orthogonal or made by the warping of a rectangular grid.

The Cone is like a volcano shape using a radial geometry created by radians and hoops to create surfaces. These two forms can be combined to create an infinite number of permutations much like the circle and the square with classical architecture.

What fabrics are used?

All fabrics will stretch when pulled in opposite directions to create tension, however some fabrics exhibit different characteristics. There are currently four types of fabrics that are used today for tensile fabric structures:

PVC coated polyester fabric

This is a cost effective fabric having a 10 to 20-year lifespan. It has been used in numerous applications worldwide for over 40 years and it is easy to move for temporary building applications. PVC meets B.S 7837 for Fire Code.

PTFE coated glass fabric (permanent structures only)

This has a 30-year lifespan and is completely inert. It does not degrade under ultra violet rays and is considered non combustible by most building codes. PTFE meets B.S 476 Class 0 for Fire Code.

ETFE foils (permanent structures only)

This is used in inflated pillow structures where thermal properties are important. The foil can be transparent or fritted much like laminated glass products to allow any level of translucency.

PVC glass fabrics

This material is used for internal tensile sails, such as features in atriums, glare control systems, with a minimal need for maintenance.  PVC glass fabrics meet B.S 476 Class 0 for Fire Code.

Are tensile structures sustainable? 

Tensile structures generally use light coloured roofs to reduce the heat that is attracted. They use very small amounts of material for large spans; they allow for natural ventilation using the Venturi effect and they provide translucency for natural daylighting. PVC polyester, expanded PTFE, polyolefin fabrics and ETFE foils can be recycled by the supplier for lower grade applications.

How much do tensile structures cost?

The cost of installed custom tensile structures can range can range from £200.00 to £800.00 a square metre.

This includes structural supports, cables and fittings, but does not include foundations which are dependent on local soil conditions. Costs vary due to complexity of design, local wind or snow conditions, quality of materials and connections, and area of structure required.

Standard frame structures with tensile membranes can be as low as £100 a sq.m installed and air structures can range from £80 to £160 a sq.m installed. Air structures do need continuous air support and as a result have higher operating energy costs than tensile structures.

Working with us

With years of experience in the industry, J & J Carter has become a name synonymous with award winning tensile fabric structures. We offer a variety of form, along with translucency, colour, clear span and softness. 

If you are interested in a tensile fabric structure from J & J Carter, or want to find out more information about our services, please contact us.

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