FEATURES
An additional 300 units were built commencing November 2013 and were completed in February 2014 . The advantages of modular construction , an alternative to traditional construction , are clearly seen at Delft . Modular construction has proved to be successful in providing affordable accommodation at high volume delivery rates , while providing quality homes to some 1 400 families .
The resident families at the Delft site have responded positively to the project . The biggest advantages the homeowners have noticed are the energy-efficient insulation qualities of the units , with reduced heating costs in winter and coolness in summer . Residents have also mentioned that keeping the internal walls clean is relatively easy and that , thanks to the slight elevation of the units above the ground , there is less dust .
The supply of residential accommodation units in kit form made it possible to utilise work teams drawn from the local community that were trained on site typically comprising six people per team , and they had only basic skills and little if any construction experience . Once trained , these teams are able to deliver a 48m ² unit each day . The simplicity of the fully-engineered design and construction allows for minimum use of skilled labour and almost total elimination of the traditional construction materials that tend to result in extended delivery timeframes inherent in conventional building methods .
The success of the Delft initiative has been built around the innovative application of ideas underwritten by an enlightened engineering approach , which makes use of modern building construction materials . A lightweight structural lattice steel grid platform anchored slightly above the ground on steel legs , requiring minimum soil levelling in most instances , forms the sub structure . Onto this the damp proof course and base floor covering of timber or fibre cement boards are applied . Insulated modular panels , manufactured by Intastor , are then bolted to the steel sub-structure , providing the walls in the form of pre-painted flat steel skins on a fire-resistant Isolite polystyrene core .
The use of colour and printed stone pattern on the steel skins externally enhance the appearance of the units . Some internal walls were supplied in a steel skin with printed ' Oregon Pine ' wood grain finish . The roofing panels were provided as a combined pre-painted IBR steel sheet externally with a 60mm insulated fire-resistant Isolite polystyrene core and a flat finished pre-painted ceiling finish internally supplied in 10.8m lengths . This provides total roof coverage in a single span reducing water ingress opportunities , unsightly joints and allows a natural roof pitch slope in both directions . It is possible to deliver eight complete units in flat pack kits on one truck delivery with all components ready for installation within two hours of factory manufacture .
Staying within the modular framework of 24m ² units Intastor was able to combine the standard module and provide the larger ancillary buildings associated with all small communities . A crèche was established in an older part of Delft in 2010 using the same process as described above . By staying within the bounds of the panel modules parameters one can , with little difficulty , achieve endless solutions to many of the social and commercial needs centred around buildings today . The modular panel product offers a basic building core that can have any number of finishes applied , from cementitious coatings to mock weatherboarding .
LIGHT STEEL FRAMES LEAD THE WAY
Another alternative housing material making waves in the industry is light steel frame ( LSF ) building technology . A decade ago , LSF technology was a revolutionary new construction technique in South Africa . It gained traction quite quickly and today , it is a viable option that , in many cases , is a more cost-effective and sustainable building material than traditional materials .
In 1994 , the new government implemented a socioeconomic policy framework to help alleviate some of the socio-economic struggles that many citizens faced . Between 1994 and 2001 , over one million Reconstruction and Development Programme ( RDP ) houses , were built to accommodate five million of the estimated 12.5 million South Africans living without proper housing .
RDP houses must be constructed cheaply , be reliable and able to withstand the general wear and tear that most houses face , whether from natural elements or from residents .
Enter Trumod steel frame construction , a long-standing member of the roofing industry that constructs between 400 and 500 light steel frame ( LSF ) roofs every month . Trumod ’ s LSF roofs will be installed in RDP housing projects across Gauteng .
Mulder Kruger , managing director of Trumod , explains that LSF trusses are an ideal alternative to wood , especially when it comes to low-cost housing because – as the name suggests – LSF trusses are light . In most cases , LSF installations do not even require a crane to install them ; they are simply lifted up by able-bodied workers .
“ On the larger spans , timber trusses are so heavy that you actually have to hire a crane to install them ,” says Kruger .
When it comes to RDP housing , cheaper is always better . That ’ s why LSF is a perfect material for low-cost roofing – the trusses are installed without the use of a crane , which can be expensive to rent and , in some parts of South Africa and other African countries , difficult to acquire . LSF trusses are also relatively easy to transport .
In addition LSF can be easily paired with concrete roof tiles , the cheapest and preferred roof tile in South Africa . The tiles can be affixed directly to the trusses .
Another key trait of LSF , which perfectly suits the low-cost roofing sector , is the lack of maintenance . LSF trusses are made from galvanised steel and , if the manufacturer abides by South African National Standard ( SANS 517 ) which specifies the grade of galvanising that is required , then , as Kruger says , “ There is no maintenance whatsoever .”
AFFORDABLE
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