Although this annual feature always seems to provide spectacular floors that ably demonstrate the level of expertise and competence within the South African flooring industry, it does no harm to take another quick look at a project that was more than spectacular and specialised.
It was unique – and really pushed the boundaries of what is considered possible with a concrete floor.
It was simply entitled the ‘pier topping project’ for the (then) new Southern African Large Telescope (SALT) in Sutherland in the Karoo. The title was the only simple thing about it, because the giant telescope, weighing 45 tonnes, was to be positioned on four legs on top of the circular concrete pier (annulus), which is one metre wide (inside diameter 14,2m; outside diameter 15,2m). To alter its position, the telescope is lifted on air cushions and rotated to the required alignment, then lowered back onto the pier.
The pier supporting the telescope thus plays an essential role in the performance of the instrument, and its accuracy in level and smoothness is critical to ensure reliably smooth movement of the telescope. Therefore, a specification of a maximum deviation of 0,5mm over the entire annulus was required which, bearing in mind the diameter and width of the pier, was an extremely tight requirement.
The surface finish had to be strong enough to accommodate the high point loading of the telescope legs, and the surface was required to remain maintenance-free for the expected life of the telescope – 25 years!
No shrinkage or cracking was allowed, cracks in the surface were unacceptable as the topping would be ripped apart by the enormous pressure of the air cushion system, but the resultant finish to the pier is so smooth and level that when water falls on it, it does not flow – quite the most unusual sight on a cementitious surface. No maintenance is allowed, and it has now been performing without a problem for over ten years – a tribute indeed to South African workmanship!
Having a feature entitled ‘Specialised Flooring´ is a bit of a misnomer, because in reality every type of flooring material can be used in specialised applications.
Carpets, for example, are regularly required to be custom-made to meet special requirements in terms of design, colour or layout, and there are many examples where no other flooring material would have been so effective.
Natural wood floors can also be tailored to meet specific designs, using patterns and a mixture of different woods to create extraordinarily beautiful floors. Although not put to any extreme test, it is also possible for laminate floors to provide any sort of pattern or design due to the photo-technology that this flooring type employs in its manufacturing process.
The demand for epoxy flooring has been enhanced by the wonderful colours and designs that can be created in these materials, and coloured, polished or textured concrete has become a firm favourite with interior designers and architects.
Vinyl flooring, of course, will always be in the forefront of flooring with specialised designs. Notwithstanding the latest innovations in luxury vinyl, modern laser and waterjet cutting techniques have provided a new dimension for vinyl tiles and sheeting to meet almost any design or layout requirement.
The main requirement for any type of indoor specialised floor such as sports floors, dance floors, school halls and stages (amongst others) is that it must be laid on a perfectly flat surface. This is often undertaken by the specialist installer, but will usually consist of a power-floated concrete surface, and/or a self-levelling screed on top.
Wood is still a preferred flooring material for this type of floor, and the planks are invariably fixed on battens. In these cases any variance in levels of the subfloor can be accommodated by using chocks under the battens.
Sprung floors are often the order of the day, and in these cases a resilient sheeting of about 10mm thickness, or rubber block pads are placed under the battens – but there are many variations on this theme.
The most common woods used in these applications in South Africa are usually either Hevea or Beech, and the pre-finished wood surface has factory-applied anti-slip protection. If the wood has not been treated in this way, a special anti-slip coating must be applied.
Gymnasium floors differ from sports floors because, although a wooden sprung floor would be required in a gym club for the aerobics areas and other activities, a rubber floor of sheeting or tiles, applied direct to the concrete subfloor, is required where weights and machines are used.
For these areas a much thicker floor (20mm or more) is required, and it usually consists of rubber sheeting. This often comprises two components of rubber: one 4-mesh layer; and a smaller 12-mesh layer on top to give more cushion. In heavy weightlifting areas where the floor is being subjected to great force, the rubber needs to be very thick, otherwise the concrete in the foundations of the building will be subjected to cracking.
Artificial grass is a truly specialised ‘flooring’ material, and never more so than when it is used to provide a high-performance sports playing surface. Manufacturers go to great lengths to provide specific playing surfaces for each type of sport and, as a result, several governing bodies including the International Federation of Association Football (FIFA) and the International Hockey Federation (FIH) promote the use of artificial turf for professional match play.
The upkeep of a sports field can be expensive due to the professional upkeep requirements which involve the costly, time-consuming tasks of mowing, aeration, re-seeding and fertilising, and in the professional leagues it is always deemed necessary to re-seed and grow a new pitch every season.
None of this is necessary with the use of artificial grass, which can be used for several seasons, and vastly reduces maintenance cost.
There are so many variations of types and specifications of the flooring to be used in sports halls and similar, that they are virtually ‘custom-made’ to meet every application, but it is interesting to note that even in rubber flooring there are new developments happening on a regular basis. The latest is an environment-friendly range of rubber flooring being imported from the UK that is made from recycled automobile tyres. It has all the advantages of normal rubber flooring, but is ‘green’ in its
Another innovative floor that really caught the eye is known as a sustainable energy floor, which converts human footfall into electrical energy with an efficiency of 50%. It is a big enhancement to a whole range of applications by providing both a unique experience and the harnessing of energy from footsteps.
For example, it is a fully recyclable, modular floor system which can be integrated in floors of public spaces. This new technology is applicable for high-footfall locations, such as stadiums, airports, railway stations, shopping malls, buildings and city squares.
The generated electricity can be fed back into the grid or used to power local systems such as streetlights or information and signage systems. Part of the energy can also be used to give feedback to users, like illumination in modules.
This is a similar application to that used in a number of green nightclubs in Europe, including Rotterdam’s Club Watt, where installed sprung floors help generate power for the music and lightshows. The floors are suspended on transducers that act like shock absorbers. To absorb the energy produced by dancers, piezoelectric crystals are used. When compressed, these crystals charge nearby batteries which can be used to light the floor or add to the décor of the room.
Acknowledgement and thanks are given to the following for information contained in the compilation of this article: Master Rubber Company (www.masterrubber.co.za); www.polyflor.co.za; Medowen Wooden Floors (www.medowen.co.za); Energy Floors (www.sustainabledanceclub.com).