Some Long Span shade cloth structures fail or do not last as well as they should. A galvanised or stainless cable can be inserted into a sheath of HDPE water pipe, the HDPE water pipe has the same heat characteristics as the HDPE shade cloth filaments.ģ. Footings, framing and attachment points. * Please note that coated cable although suitable in most areas can become pliable in extreme heat and adhere to the HDPE fabric causing wear and rubbing.

Details which are susceptible to fatigue due to movement under wind loads.

Details which cannot cope with the rubbing of uncoated cables in edge pockets*.Poor quality or insufficient sewing in areas of high stress such as corners, reinforcing areas etc.Poor detailing, especially reinforcing details in areas of high stress.Sewing which is unable to stretch as much as the shade cloth itself causing failure of the threads.Using sewing thread which has a shorter life than the shade cloth itself,.Poor detailing and fabrication of shade cloth issues include A better sharing of loads between Warp and Weft fibres resulting in less elongation of fibres over time and thus a better ability for the shade sail to retain its original design shape.More equal prestress loads in both Warp and Weft directions,.A more even distribution of forces into supporting structures,.When designing shade cloth structures, similar structural properties in both Warp and Weft directions, as exhibited by the new Gale Pacific Commercial Heavy ensure Shade cloth choice, detailing and fabricationġ00% monofilament shade cloths are the longest lasting shade cloths and the most suitable for long span shade structures. When the site conditions restrict the amount of curvature that may be obtained, a very stiff shade cloth with balanced Warp (lengthwise) and weft properties like New Gale Pacific Commercial Heavy reduces the influence of less than ideal curvature.Ģ.The less stiff the shade cloth the greater the problems caused by a lack of curvature.These sails once compromised then start to billow in the wind which shortens their life even more. Planar surfaces such as flat sheets or triangles only take load by stretching rather than changing shape which leads to greater stress on fibres and generally a shorter service life. A shade cloth surface has to be 3 dimensional and able to change shape in response to applied loads.Flat/insufficient slope panels also tend to fill up with hail.This causes the shade cloth to stretch excessively and effectively beat itself to death. Sails which are too flat, (lacking curvature) lead to billowing.

Generally, significant curvature allows a shade cloth to span further and retain its design form better than a shade cloth structure with little curvature. The long span shade cloth structure should have fabric curvature and initial pre-tension to work satisfactorily.Ī long span shade cloth membrane with significant surface curvature will develop less stress in the fibres compared to one with little curvature.

This is a list of common manifestations of improper engineering.

It is necessary to ensure that the design of long span shade cloth structures is undertaken by a registered engineer experienced in the design of fabric structures. It only takes one of these items to be done improperly to compromise the performance of the long span shade cloth structure. The problems that may be found with long span shade cloth structures can be generally traced to an overall lack of proper engineering which includes the choice of shade cloth, hardware, support framing and footings and poor installation. However, this report will not focus upon the nature of these forms as no matter what the form of the structure the same principles and issues apply to all long span shade cloth structures. Long Span shade cloth structures (structures with a span of over approximately 7 metres) come in various forms including The most important principle to remember is that every component of the long span shade cloth structure has to be designed, fabricated and installed correctly. This report considers the issues and problems associated with Long Span Shade Cloth structures with particular reference to the New Gale Pacific Commercial Heavy shade cloth.