Question 1: What is PVC Fabric?

Answer 1: Woven polyester with PolyVinylChloride

Generally using a polyester woven base cloth, PVC fabrics are coated with various polymers then a special material to give the material colour, strength and waterproof properties. There are many different top surfaces applied to PVC fabrics ranging from basic acrylic coatings to highly specialised self cleaning finishes like PVDF which prolong the life of the fabric. PVC fabrics are described by their finished weight in grams per square meter. Many different thickness fabrics with different life expectancies are available; generally thicker fabrics have extended life spans. Coloured fabrics are available but usually only in the lighter acrylic coated variants.

Question 2: What is PTFE Fabric?

Answer 2: Woven fibreglass with PolyTetraFluroEthylene (Teflon like) coating

Unlike PVC, PTFE fabrics use a woven base yarn of glass fibres. The top coating is an extremely high grade Teflon like slick surface that prevents a build up of contaminants, resulting in an extended life span. PTFE fabrics are much more time consuming to manufacture and budgets for PTFE projects are much higher than projects using PVC fabric.

Question 3: What is a Catenary?

Answer 3: A curved or “scalloped” edge of a fabric structure

A Catenary is a curved edge generally around 6-10%. Fabric is manufactured with a pocket to insert a stainless steel cable or rod which is fitted with adjusting devices allowing the fine tuning of the length to suit the fully tensioned fabric skin. Without correctly designed catenary edges, the central area of a fabric skin is not under the correct tension and will result in flapping and sagging.

Question 4: Why do you call them Membranes?

Answer 4: They are 1 piece

To survive under extreme weather conditions and decades of service, there are many aspects of a tension membrane structure that need to be designed correctly. The goal of a tension membrane structure is simple: adequate and even tension across the 3D surface of the fabric. To achieve this even tension, several intelligent choices must be made with respect to:

- Fabric choice
- Catenary curves
- Correct Prestress
- Patterning and design
- Adequate 3D shape
- Suitable structural supports
- Link lengths
- Accurate measurement
- Fabric manufacture

Fabric is assembled using large machinery. For PVC structures, high frequency welding results in the fabric joins being as strong as the fabric itself hence the term “Membrane”.

Question 5: What do you mean by shape?

Answer 5: 3 Dimensional curvature

Curvature in 2 directions at any point on the surface of the fabric. Simplest form is a 4 pointed structure with 2 diagonally opposite points high and 2 diagonally opposite points low, resulting in a “saddle” or “twisted” form, this is correctly known as a Hypar.

Shape is completely different to pitch or fall. Unlike conventional roofing, the amount of pitch or fall on a fabric structure is irrelevant to it’s 3D shape. The amount of 3D shape on a structure is related to it’s life span. Flat or 2 dimensional structures (regardless of the fabric type) will end up sagging, flapping, loosing their tension and ultimately failing. Structures with a good amount of 3D shape will deal better with high winds, retain their tension better, drain water more efficiently and result in surviving for many, many more years.

How much cheaper for a mesh structure?

Answer 6: Not much, if at all!

Fabric choice is governed by many factors. A large range of fabric grades, weights, types and colours exist in the industry. A number of high quality mesh fabrics are available. However any mesh fabric has a number of disadvantages vs a solid waterproof fabric such as:

-Being a mesh fabric, airborne dust and dirt are trapped or filtered, resulting in dirty and ugly appearance
- More frequent cleaning intervals due to above
- The buildup of dirt allows for mildew to grow on the surface of the fabric, significantly shortening it life span

Generally speaking, the manufacturing, all labour, hardware and techniques are all the same for mesh fabrics and waterproof fabrics. The cost of the material is the only difference. Some high quality meshes can actually be more expensive than solid waterproof fabrics.

Do you offer a design service?

Answer 7: Absolutely!

Designing fabric structures is something we’ve perfected over many years. The service allows our prospective clients to also benefit from this experience. The fee for the service depends on the details but is more often than not detectable from the cost of the project should it come to fruition.

Question 8: How far do you travel?

Answer 8: We travel throughout Europe and Middle East, some parts of Asia and round the Mediteranean sea. All operations are controlled from our head office.

Question 9: Do you do residential work?

Answer 9: Yes we are specialized and have many years of experience! As we operate in the top end of the shade market with respect to quality this generally results in a product that is overkill for a domestic application.

Question 10: How long does one of your structures last?

Answer 10: A long time

Low maintenance materials and clever design and engineering result in a long term shade solution. Fabrics are warranted for up to 15 years and life expectancies in excess of 25 years. Fabric structures can be engineered to withstand the worst Mother Nature can dish out. Many structures overseas have been in service for 30+ years and are still going strong.

Question 11: Do you have to clean them often?

Answer 11: No, but it will extend their life

Maintenance is periodically required depending on amount and type of pollutants as well as the structures exposure (working environment). Generally speaking a bi-annual wipe over of the fabric surface with water and a sponge is all that is required to give many years of service. Of course more stringent and frequent maintenance helps extend the life and condition of the structure. Fabrics and supporting 316 stainless steel wire fittings, etc are generally regarded as low maintenance. A correctly designed structure with plenty of 3D shape does not usually require re-tensioning at all.