Profile Shade Structures has an experienced team who will visit the site and will advise the client of the functional shape of the shade structure, best suited to cover their required area or venue.
Shade structures fall into two main types. Those using waterproof architectural fabrics that transfer tensile loads into the designed structural steelwork. Or typical lightweight shade cloths with posts and cables tied back to ground level with concrete or screw anchors to resist the lateral loading.
After a detailed survey has established the attachment points, the data of the co-ordinates is transferred to specialised computer software that carries out a structural and finite element analysis of the structure.
Loads on the attachment points, fabric patterns, sizes and lengths of the catenary cables and the sizes of the structural steel are all determine by specialised computer software, thus ensuring a structurally designed and perfectly tensioned membrane structure.
From the structural engineers certified drawings, the detailed shop drawings are produced and submitted to the client for approval. The columns, rafters and attachment plates are fabricated and hot-dipped galvanised ready for transport and erection.
The computer-generated fabric patterns are passed to a laser cutter that produces each panel of the membrane. These are then joined with a high-frequency welder to form the final shape.
The coated structural fabric consists of a woven polyester base cloth stabilised and protected by PVDF (thermoplastic fluoropolymer) coating on both sides. They has a tensile strength of 10 tonnes/linear meter in the warp and weft direction. Normally working on a factor of safety of 6 on maximum design loads, the maximum permissible load would be 1.7tonnes/meter and a typical prestress load applied during tensioning would be 350kg/m. All structural fabrics stretch under the initial prestress but remain static after reaching full pretension. The membrane patterning software adds in these compensation percentages and the canopy is manufactured undersize so that when installed to its final designed dimensions it tensions out correctly.
A mesh fabric or shade cloth is a woven material with spacing between thread bundles. These fabrics allow for wind and water to dissipate through them and do not require the same strength of support structure. They are tensioned by installing a stainless steel cable in a pocket sewn into the edges of the sails.
A team of experienced riggers are employed for the erection of the structural steelwork and the installation of the fabric with the correct tension to obtain a wrinkle-free fabric surface.