Your roof is a structurally important and very costly component in any construction project. The average cost of a roof as a component of the final building cost can easily exceed 25% of the total cost. The cost of repair or replacement will be more than this quoted percentage due to the additional work that will be required to establish structural integrity. This work will include re-fitting of water and electrical services, including the finishing detailing that will have to be redone.

Important information:

  • The average house will have a dead load of ± 20 tons, and will need to be designed to provide for live and wind loads.
  • Most roof repairs cannot take place while the building is occupied and generally the occupants will have to be re-located at a considerable cost.
  • Roof failures are a serious health risk, and can cause death should a collapse event occur.
  • Home Owners Insurance will not make payment towards repairs, where it can be proven that the roof structure was not in compliance with the National Building Regulations.

Timber roof structures must be designed, manufactured and erected in accordance with:

  • Part L of SANS 10400 for ‘Deemed to Satisfy Requirements’
  • SANS 10243 for Manufacturing and Erection of Timber Roof Structures
  • SANS 10160 for determining the loads that will need to be accommodated by the structure
  • SANS 10163 for the use of timber in a structural application
  • SANS 1783 for the grading and treatment of structural timber

Design and manufacture:

All nail-plated timber roof structures must be designed by a professional engineer and in accordance with the above stipulated SANS requirements. These designs must be applied in the manufacturing of the roof structures, and only by Institute for Timber Construction South Africa (ITC-SA) certified Fabricator Members who have been awarded a Certificate of Competence.

For help or more information, contact the ITC-SA, email

Image supplied by MiTek Industries SA.