SA Roofing February 2018 // Issue 97 - Page 29

FEATURES too much, but implementation of details wasn’t great, partly because of unclear details sent to site. That made it difficult for everyone,” he explains. He believes that improvements and access to technology has greatly benefited the industry and is quickly bringing about positive change through transparency and clarity. ITC-SA’s role A roof inspector’s role isn’t well known, and their services are not often enlisted due to a lack of awareness of the importance of roof inspections. Booth and Ken Downhams who started Roof Inspection Services. The pair were trained by them and received certification. After certification they registered with the ITC-SA as qualified roof inspectors. According to Bailey, the law states that if anyone wants to erect a structure, then it needs to be approved. “It’s the responsibility of the owners to recruit a qualified engineer to approve the roof. There are two ways of getting approval: one way is by referring to the National Building Regulations (NBR) deemed-to-satisfy table; however, this only counts on simple houses with gable-to- gable roofs that span no more than 8m. For more complicated roofs, a designer and a professionally registered individual who complies with the NBR and by extension, municipality requirements, should be recruited. “Second edition Construction Regulations released in 2014, state that every building `must have a structural inspection every year,” he explains. This is unfortunately not well known in the industry and it is most often only when there is structural failure that annual inspections are conducted. Bailey says that some of the buildings he’s inspected that were built over two or three decades ago, are now failing. “These buildings weren’t inspected. No-one supervised the erection, so we’re finding unbraced roofs that are 20 to 30 years old,” he says. The reason behind some roofs only caving years later is because timber is a ‘patient’ material because of its elastic qualities. Stian de Jager explains, “A terrible roof can take many years to fail, sagging without owners noticing it. That’s the danger that isn’t so well known. If timber wasn’t so ‘patient’, we wouldn’t have roofs that are signed off so casually. Sometimes, after 10 to 15 years is when you can have a catastrophic collapse.” However, Bailey maintains that, with the ITC-SA’s contribution to creating and maintaining high standards in the timber construction industry, things have changed. There is now greater supervision on site and awareness that roof inspections as well as bracing on a roof are essential. “On-site bracing has improved and the process of checking it has also become better over time,” he says. He adds that some roof truss manufacturers go as far as visiting the site and inspecting the roof themselves before calling in the inspector. Improvements that Stian de Jager has seen include overall raised standards of roofing. “It hasn’t solved all the problems as too many roofs are going up unnoticed,” he says. He recalls that when he started it was quite serious with site made trusses going up for complex roofs. Thanks to the efforts of the ITC this has greatly improved, especially in the metropolitan areas. There were also very poor drawings going to site. “It was very hard to get drawings on site to inspect what was being designed. General carpentry skills were never lacking As South Africa’s professional body for the engineered timber construction industry, the ITC-SA has also helped to educate municipalities on the importance of roof inspections, which have since gained traction. ITC-SA national coordinator, Amanda Obbes, says that the industry is strictly monitored, and members must undergo annual audits through the inspectorate. The ITC-SA also offers ongoing roof inspector courses that are open to anyone with a minimum of five years’ experience in the roofing industry. “Background knowledge could also include quantity surveying and architecture, although we also accept students that are learning or considering becoming an inspector,” she says. The course covers basic roofing terminology, such as rafters, tie beams, webs, gables, hips, truncated hips, spans, overhangs, cantilevers as well as prefabricated / bolted methods and addresses the basics of timber design, including loading, information of the relevant codes, explanations of permissible stresses and limited state loading as well as tributary loading. Bracing in roofs in general is also addressed, with a more practical look at the differences between lightly versus heavily loaded roofs based on field experiences presented in visual format. In addition, rafter bracing, including the need for different bracing systems as well as an overview of standard bracing details, is also highlighted. Course content also touches on tie beams and web bracing, including standard bracing details, case studies showcasing roof failures and the reasons for these, as well as the administrative tasks involved in being a successful roof inspector. A general overview of the roofing industry in South Africa highlights the main role players in the sector and what their responsibilities RESIDENTIAL // COMMERCIAL // INDUSTRIAL FEBRUARY 2018 27