The use of light steel frame building (LSFB) has been growing steadily for the last seven years, partially owing to architects looking for alternative building methods to overcome the inefficiencies of conventional masonry building, says the Southern African Light Steel Frame Building Association (Sasfa).
Sasfa director John Barnard explains that the association has been logging LSFB projects for the past seven years. Last year, 400 000 m2 of buildings were built using LSFB, as well as 1.5-million square metres of LSFB roof structures, replacing timber, he adds.
He notes that LSFB techniques ensure a faster building process, with much less waste than is the case with masonry building.
LSFB has been used in larger projects in South Africa, like the 27 500 m2 curtain wall of the Mall of Africa, in Midrand, Gauteng.
However, Barnard says the largest LSFB project in Southern Africa to date is the residential complex built in Zimpeto – a suburb of Maputo, in Mozambique – by American company Worthington Construction.
“With a floor area of 100 000 m², Worthington Construction built the 27 blocks of four-storey buildings, comprising 848 three-bedroom, two-bathroom flats in only eight months. This would not have been possible had they not used LSFB.”
Barnard explains that LSFB challenges conventional building processes with new and more energy efficient ways of achieving the requirements of buildings in South Africa. LSFB projects have to be built in accordance with the South African code for LSFB (SANS 517).
LSFB projects have internal walls lined with gypsum board providing a superior base for paint, because it is smoother than a plastered wall and without imperfections, he adds. An added benefit of LSFB internal walls, is that they are precisely vertical, providing a neat finish between the cupboards and walls.
Barnard explains that there are 20 manufacturers of LSFB structures in South Africa which are located in Gauteng, KwaZulu-Natal, the Eastern Cape and the Western Cape.
However, he points out that the location of LSFB manufacturers in South Africa is not that important, as LSFB sections can be transported in bundles and assembled into frames and trusses on site, reducing the cost of transport of assembled panels or trusses.
Most of the steel used for LSFB is sourced from South African manufacturers, such as integrated steel and mining company ArcelorMittal South Africa, steel processors Duferco Steel and steel supplier Safal. The only company that exports steel for the South African LSFB industry is steel company Bluescope Steel from Australia.
“LSFB materials are not cheap, but savings are possible through good planning, which will accelerate the building process and result in less building material waste. “As the LSFB walls are 90% lighter than plastered double brick walls, coupled with the flexibility of the steel framework, the demands on foundations are reduced, offering savings,” he explains. He adds that LSFB also needs less reworking because the structure has already been built to precise measurements.
Further, LSFB is easy to insulate and can, therefore, be erected throughout South Africa to fully comply with SANS 10400 XA and SANS 204.
He explains that Sasfa offers a six-day training course for building contractors to learn the basics of LSFB and thereafter the best way for new contractors to learn is to gain on-site experience with experienced builders.
The speed of construction and energy efficiency, he concludes, make LSFB the building method for the twenty-first century.