Imagine your dream tensile structure and you will no doubt envisage a splendidly white, taut, smooth hyperbolic paraboloid. But, without due care, dust, pollution, water, sun and cold can cause your dream structure to become tired and shabby.
To ensure a long lasting performance, like any other construction, a tensile structure has to be maintained and its shape and tension checked frequently.
Keeping clean
Dirt and dust can harm the membrane. In intensely wet environments, extensive mould can leave permanent pigments on the surface.
Textile architecture should be cleaned according to the recommendations of the manufacturers of the membrane. The recommended physicochemical policies must be adhered to in order to maintain the original quality, without damaging the surface – usually varnished – and so there is no chemical attack
on the raw materials used in manufacturing.
Generally, we recommend the use of pH-neutral detergents, shampoos and water applied with a soft brush. Stubborn dirt can be removed with hot, pressurised water.
Many membrane manufacturers have their own brand of shampoo, or recommended ones. In some parts of the world it can be difficult to get such products due to shipping costs, time of transfer, customs and tax issues. Samples of some soaps and shampoos obtained by common trade in the local market were
sent to the membrane manufacturer for laboratory testing. Even products specified for use were rejected while others made for other uses were approved.
As shampoo and water can create a very slippery surface on a geometric tensile structure, officials in charge require specific and appropriate personal protective equipment.
The scope of product warranties has extended in the general construction industry, and textile architecture is no different. Manufacturers of membranes should ensure that warranty documentation requires the end user to keep up to date with maintenance and proper cleaning. This increases the shelf life, sustainability and good image of the product.
In case of stubborn stains caused by chafing, fungi, moulds and other physicochemical agents that have changed the original condition, we enter into an area where the manufacturer’s warranty is usually no longer valid. There are solutions on the palliative level that tend to reduce the negative aesthetic impact of these situations. Chlorine and petrochemical products have been used, although prohibited by the manufacturers of the membranes, often with satisfactory results in short-term. In extreme cases there are even attempts to paint the membranes, with rapid deterioration and subsequent bad results.
Cleaning works of textile architecture should always aim to maintain good appearance and prolong the project`s life, improving the image of the product on the market while acting sustainably and protecting the owner’s investment.
Keeping in shape
Textiles should also behave as a shell and maintaining that architectural form is crucial. It is up to the owner to get technical support to assess the physical condition of the work. Specifically, the tightness of the surface should follow the correct characteristics, taking into account the natural loss of strength over the years.
This is not only for appearance: the behaviour of the structure depends on surface stress. A weak surface stress may lead to extensive flutter under wind condition, membrane fatigue and even collapse.
Loss of surface tensions fails to ensure the structural rigidity needed to perfect functioning of the membrane and it ceases to act as a shell. Under these conditions the action of wind and other load-generating natural factors can cause flutter and consequent fatigue, preventing proper operation and rupturing
the tissue in short time.
By regularly checking and controlling tightness, you guarantee good structural performance and long service life.
Flexible membranes are generally married to metal brackets and other structures with lower rates of expansion. The interaction between such different materials has always been a sensitive issue in the construction industry.
To keep tension at levels necessary for proper structural functioning, designers have developed and used a series of mechanical devices, such as tensioning cables and regulating screws that distributing localized stresses and friction. These devices are responsible for the integrity of the normal working tension of each project and are used, in maintenance, to restore the original conditions when necessary.
