TIMBER
Erik Söderlund
An often-overlooked consideration when solar panels are installed is the design capacity of the existing roof structure, writes Erik Söderlund, General Manager of the Institute of Timber Construction SA.
Roofs in South Africa should be designed to withstand loadings in accordance with SANS 10160 parts 1 to 8. Of particular importance are Part 2, Self weight and imposed loads, and Part 3, Wind actions.
If a roof structure is not installed in accordance with its design or has additional loads imposed on it for which it was not designed, catastrophic failure is possible. With the rapid roll-out of rooftop solar, this risk is increasing because many older homes were never designed to carry the additional sustained load of PV panels.
When designing and supplying new roof structure, it is relatively easy, and does not necessarily cost much more, to accommodate solar panels. However, the homeowner must still ensure that the location and weight of the installed panels accord with the structural design.
Planning to install solar panels?
A building owner remains responsible for ensuring that the house complies with all applicable regulations and standards. The OHSA Construction Regulations( 2014) require a structure to be suitably designed and erected, as well as inspected periodically by a defined Competent Person. Inspections must take place at least once every six months for the first two years and annually thereafter for workplaces, commercial structures, and public buildings.( Private homes fall directly under SANS 10400 – Ed.).
When any change to the roof loading is planned, the homeowner should appoint a Competent Person with appropriate public indemnity insurance to inspect the roof. This effectively passes the legal responsibility of compliance of the roof structure over to the Competent Person.
An inspection of the roof ' s capacity to carry the additional sustained load may conclude that no structural modifications are required. This will depend on the planned additional weight and its location on the roof structure.
When paying for a structural inspection, homeowners should verify the credentials of the person taking responsibility. An ITC- SA certificate must include the signature of an ITC-SA Engineer Member. An ITC-SA Certified Roof Inspector inspects on behalf of an Engineer Member and cannot issue a certificate without the engineer’ s oversight and signature.
Failure to verify that a roof structure can carry the additional sustained load of solar panels could comprise an insurance claim should the structure fail. When purchasing a property with solar panels, the buyer should request a suitable roof certificate from a Competent Person. For timber truss roofs, it is advisable to use an ITC- SA member.
The ITC-SA is the SAQArecognised professional body and ECSA-recognised voluntary association for the sector.
Find an ITC-SA member at www. itc-sa. org / members-directory or email enquiries @ itc-sa. org to verify their membership.
80 spring 2026 | www. tobuild. co. za