Light steel frame building (LSFB) is increasingly becoming the preferred building method in the Southern African Development Community, says Southern African Light Steel Frame Building Association (Safsa) director John Barnard.
“LSFB allows for a neat, organised and clean building site with low traffic density. If you add the other benefits such as speed of construction and long-term energy efficiency, one can understand why this method has grown so quickly in popularity in Southern Africa,” he explains.
Barnard cites the completion of an out-patient hospital in Mbabane, in Swaziland, as a prime example of the LSFB method’s success. The project, which was completed earlier this year, was undertaken by South African supplier and lightweight steel frame products fitter Razorbill Properties, under instruction from the principal agent Ramashka Architects Swaziland, for the Swaziland Ministry of Health.
The clinic will serve as a day clinic to alleviate the patient load from the neighbouring main hospital. Provision has been made for a link bridge between the clinic and the main hospital to facilitate a free flow of pedestrian traffic between the two facilities.
“This project is yet another excellent example of the benefits of LSFB. Even if you take only the advantage of being able to construct a substantial building right next to a hospital without interrupting the daily operation of that hospital, it would be reason enough to choose LSFB instead of dusty, noisy, labour-intensive masonry construction,” says Barnard.
Razorbill initially presented two different LSFB solutions to the client, one of which was Agrément certified and the other a rational design to SANS 517 LSFB levels.
“The benefits of opting for the rational design route included the speed of construction, thermal insulation complying fully with SANS 10400XA - ensuring energy efficiency over the lifetime of the building, site neatness and a building process that would minimise interference with patients and ongoing main operations,” says Razorbill CEO Chris Smith.
Smith notes that the project site had some challenges in terms of the topography, site access roads, sewage lines, storm water systems and available space on site for the offloading and storage of building materials. In addition, the construction tasks were split between different companies, with the re-routing of sewer lines, installation of storm water systems and foundation and slab installation being awarded to a local Swaziland contractor.
“The fact is that LSFB minimises the volume of building materials required on site so we were able to overcome the site constraints. Based on our experience on several other project sites where foundations were outsourced to civil contractors with little or no experience in LSFB, Razorbill decided to employ a fulltime quality control officer on site to help ensure that the foundation was compliant with the standards and tolerances as required by the SANS 517 building code. This decision proved a very worthwhile one indeed,” adds Smith.
The scope of work included the rolling of about 100 t of 0.8 mm and 1.2 mm LSF sections – for which steel producer ArcelorMittal South Africa’s (AMSA’s) ISQ 550 high strength galvanised steel sheet was used. This was undertaken in Vereeniging. It was then transported to Mbaban. The assembly and erection of all the LSF panels ultimately involved the placing of 16.5 t of heavy structural steel, the erection of 3 700 m2 of fibre cement board external cladding (supplied by roofing and cladding solutions provider Everite), the installation of 14 200 m2 of internal lining comprising 15 mm thick fire stop and moisture resistant gypsum board and gypsum ceiling board from ceiling and architectural solutions provider Saint-Gobain, and the erection of the roof, consisting of AMSA’s chromadek roofing.
The hot-rolled steel sections were used in the project to achieve the heights and spans required in the building. “This was designed by South African engineers and the manufacturing was outsourced to local Swaziland engineering firms,” explains Smith.
He adds that a significant amount of material was also procured in Swaziland, and Razorbill furthermore trained and employed about 110 local people for the project. “The job creation for locals is consistent with Razorbill’s strategy of maximising suitable benefits for the local communities in which the projects take place,” says Smith.
Owing to the energy efficiency of LSFB, Razorbill has been approached for another construction project in Swaziland. Barnard adds that the association has had two senior building inspectors from Swaziland attend its training course for building contractors, which was presented in March in Gauteng. He further notes that South Africa’s Presidential Infrastructure Coordinating Commission is encouraging the use of innovative building technologies, such as LSFB, for all new hospitals, clinics, schools and student accommodation in South Africa.
“The ability to achieve complex and aesthetically pleasing designs with LSFB is no longer in doubt and, given LSFB’s significant contribution to a growing movement of sustainable and cost-effective building, the advantages of LSFB to developers and the environment at large can no longer be discounted,” concludes Barnard.