Frequently Asked Questions
Please do not hesitate to contact us if you do not find your question below.
1. What are you prepared to do for free?
2. How long will a tensile structure last?
3. What about wind and snow loads?
4. Are tensile structures expensive?
5. Can you describe the fabrics available?
6. What does your service include?
8. How green are tensile structures?
9. Can you have insulated canopies?
11. What warranties do you offer?
12. So what’s new in the world of tensile architecture?
14. Where does ETFE fit into the scheme of things?
15. Can you use fabric to help with acoustics?
16. How often and how should you clean tensile structures?
1. What are you prepared to do for free?
We are really pleased to work with potential clients in developing initial ideas and also providing outline costs.
If, for instance, you can supply a drawing or even a rough sketch of the area you want to cover, we can give you a budget estimate for a fabric canopy within 24 hours. We can also provide examples of similar canopies we have created and we’ll follow this up with a sketch of how your canopy might look.
On larger projects we may undertake some preliminary analysis without any forward commitment, to provide you with some feedback on shape, loads and costs that you can build into your proposals.
2. How long will a tensile structure last?
This will depend on the materials used. So 35-40 years if you specify a PTFE or silicon coated glass cloth - otherwise 15-20 years for PVC-coated polyester fabrics. The rest of the steel frame and cables will be good for 50 years. To keep the structure looking at its best and operating safely, some routine maintenance will be required, and we can advise on this.
3. What about wind and snow loads?
Every structure we design satisfies the British Standard Codes for wind and snow loading (BS 6399 parts 2 & 3). We will also take into full account its location, height and surrounding buildings and if it is designed for permanent or just seasonal use. Please be aware that some companies offer sail shade structures that are inevitably lower in cost, but are not engineered for year-round use. If this is what you require, this will need to be incorporated into the specification.
4. Are tensile structures expensive?
A useful comparison is with other types of translucent roofing. A fabric structure over a shopping mall or school internal street could be half the cost of a toughened glass roof - particularly as the steel frame can be much lighter as it only needs to take a fraction of the dead weight.
However, bespoke fabric structures would struggle to compete with clear triple wall polycarbonate. The cost, of course, also needs to be weighed against the application and the appearance. Click onto our fabric matrix download and you can see how the various types of structure compare in cost.
5. Can you describe the fabrics available?
This will be determined by the application. For external structures we work with PTFE (Teflon) coated glass, Silicon coated glass, TENARA (PTFE coated PTFE) and PVC coated polyester. We also offer a single skin ETFE framed ‘glazing’ system.
For internal structures there is a wealth of choice - from sunscreen meshes and lycras through to polyesters and synthetic silks.
All are fire rated and all the external fabrics are supplied with the manufacturers warranty.
A full comparison chart is available here.
6. What does your service include?
We offer a one-stop shop - from design, manufacture, installation and through to after sales maintenance support. We can supply everything above foundation level - ie the steel frame, tie rods etc – and even glazing and cladding if these are closely integrated in the design.
It’s a real missed opportunity if you don’t consider lighting your fabric structure. We can work with your lighting designer or offer our own services to maximise the visual impact. By either back lighting or front/up lighting you can achieve some remarkable effects. For some inspiration, check out our portfolio selection here.
8. How green are tensile structures?
Tensile Fabric structures are probably the most efficient method of achieving long span enclosures. Compared to conventional steel frame and glass alternatives the embodied energy is significantly less. Conversely, though, tensile structures usually require larger concrete foundations due to the tensile loads.
One of the biggest contributions fabric can make environmentally is in the overcladding of structures where savings of up to 40% in the energy required for cooling have been recorded.
For more details on the merits of each fabric check out our fabric matrix.
9. Can you have insulated canopies?
Yes you can - using two layers of fabric with a suspended insulation layer in between. The only drawback is that you lose the benefit of translucency, unless you use a high translucency insulation, such as nanogel.
Fabric can be slashed. That is why we design our canopies to be sensibly out of reach if they are in vulnerable sites. Most fabrics can be patched and repaired in situ, or can be designed in panels that can easily be replaced.
11. What warranties do you offer?
All fabric manufacturers offer fabric warranties which can vary from a standard five years up to a 15 year sliding scale warranty – all depending on the fabric and the supplier. Our fabric matrix provides you with the design life of different fabrics which is a better guide to how long materials can be expected to last the course.
12. So what’s new in the wonderful world of tensile architecture?
Well here are just a few things we are excited about:
A new family of high translucency PVC /polyester fabrics has just been launched. They offer around 30-40% transparency and can be used on their own or integrated into a fabric membrane to form varying translucencies.
Fabric facades… over cladding an existing façade can transform a building visually as well providing massive energy savings. Download the TEXO® presentation pdf(1Mb)
Yes we do. We have an agent covering Scandinavia and have installed projects in the USA, Europe, the Middle and Far East. Where possible, we will utilise local resources for steel manufacture and skilled labour to reduce costs and our carbon footprint. All installation work would be controlled by our own site supervisors.
14. Where does ETFE fit into the scheme of things?
ETFE foil has made a huge contribution to the architect’s palette of materials. I only need to mention the Eden Project for proof. We see its major potential in the future not so much in the form of inflatable pillows, but mounted as a single skin in framing systems as a substitute for glazing. ETFE is the material of choice if you need high visibility as opposed to just translucency. For a case study of where we used ETFE as an alternative to a glazed barrel vault, look here.
15. Can you use fabric to help with acoustics?
A layer of fabric has very little mass and therefore it cannot absorb sound to any useful degree. Having said that, there is one mesh fabric that has been engineered to reduce the higher frequencies in quite a useful way.
Otherwise fabric can be used to disrupt reverberation times in noisy atriums by reducing the area of hard surfaces with use of suspended sails. These ideally would be using a mesh or perforated fabric.
16. How often and how should you clean tensile structures?
Translucency is one of the major benefits of tensile structures, so keeping them clean has to be an advantage. But compared to glass, the cleaning regime is substantially less demanding - usually amounting to an annual wash down with soapy water and soft brush.
Most structures can be cleaned from cherry pickers with telescopic brushes; but with deep plan canopies, trained rope-access operatives should wet wipe the canopy with the help of water filled backpacks. The frequency required will depend upon the location, with structures in high profile city centre sites benefiting from a six-month cycle.
Canopies under trees need particular attention as accumulating leaves can cause discolouration.