“However, the main purpose of a roof is to protect the rest of the structure, regardless of whether it is a residential home or a large commercial structure.  The roof of any structure is key in the building’s design – it is arguably a building’s most important structural aspect. Without a good roof, one that functions in a manner compliant to the overall building design and functionality, everything in that structure would be left at the mercy of nature,” explains van Greuning.

He emphasises that, unlike plumbing and electrical installations, in South Africa, no certificate of competence is required for the erection and installation of timber roof trusses: “The design and manufacturing portion of any timber roof project is well regulated and for the most part, these regulations are well implemented and adhered to. The problems arise with the regulation and controlling of the erection of roof trusses, as there are no statutory requirements for the erection of pre-manufactured roof trusses in South Africa. As a result, trusses are often erected by unskilled and inexperienced labourers – this can lead to disastrous results.”

The roof structure as a whole must be designed and installed to carry the various loads. Van Greuning says that the average residential roof, measuring approximately 250m², weighs in the region of approximately 30 tons, and that the entire integrity of a structure is derived from the soundness and structurally correct erection of the timber roof trusses.

When building, renovating or repairing a roof made from nail plated timber trusses, always ensure that you contract and subcontract to companies that are accredited by the ITC-SA. Each of these companies will carry a Certificate of Competence as proof that it is audited annually by the ITC-SA. The ITC-SA has functional sub-brands that cover all aspects of timber roof trusses, from design right through to installation, which consist of the following: • System members who develop and provide software for the design of nail plated timber roof trusses. • Engineers with substantial experience and proven competence in timber engineering. • Truss fabricators that design, manufacture and supply pre-fabricated nail plated timber trusses according to the desired standards. • Erectors that install and erect prefabricated nail plate timber roof structures. • Roof inspectors, who are accredited and trained by an ITC-SA recognised professional engineers, enabling them to inspect your timber roof structure in compliance with the National Building Regulation A19.

“Simply put, if a homeowner has any issues regarding the design, construction and erection of their roof by
an ITC-SA-accredited company, through the institute’s disciplinary procedure and its code of conduct, they will have recourse that will be completely dealt with by the ITC-SA. If the erector is not ITC-SA-registered, then it will become a civil matter and will need to go to court to be settled,” explains van Greuning.

To find ITC-SA-accredited professionals, you can visit the institute’s website (www.itcsa.co.za) and click on the “members” tab. The ITC-SA has branches located nationally – check the website for a branch nearest to you. For peace of mind with regards to the protection of a large investment , as well as for the safety and security of those living in your home, choosing an IT C-SA-accredited company for all your timber roof truss requirements is the only way to go.

For more detailed information, refer to ITC – Institute for Timber Construction