FEATURE
No shortcuts when designing and building a roof !
By : The Institute of Timber Construction ( ITC ), edited by Rory Macnamara
The roof of a building is there to protect the inhabitants against the elements , therefore there can be no shortcuts when designing and building . Failure to have the roof designed by a competent person and or using inferior materials can seriously affect the structural integrity of the roof structure .
Affordable Housing does not mean cutting corners , but
delivering the best quality at an affordable price for safe and secure living .
SA Affordable Housing spoke with the Institute of Timber Constructions ( ITC ) on the issue of trusses and fasteners and established that designing trusses and the truss connections is no simple task ; requiring one to have extensive knowledge in engineering and the application of the national standards .
SANS 10160 and SANS 10163 are the national standards that are to be used when designing timber structures . Another point that was established was that the cause of more than
95 % of the roof failures in South Africa is due to roofs that have been incorrectly installed by persons not having the knowledge of how to correctly install and brace the structure . SANS 10243 is the national standard used for the installation and bracing of roof trusses .
The ITC has two publications that are used extensively throughout the timber roofing industry on how to correctly erect and brace a roof structure . These publications are : Roof Erector ’ s Handbook , Volumes 1 & 2 . The ITC also offers short training courses on the erection and bracing of roof structures .
It is not just about the truss and fastener , but the following , sometimes obvious , but not always , put into practice :
ALL IMAGES : INTERNATIONAL TRUSS SYSTEMS
Looking at the critical considerations around trusses and fasteners , with respect to metal nail plate fasteners , one needs to ensure the fasteners used to build the trusses are the same as what the trusses were designed to use .
24 JANUARY - FEBRUARY 2021 SAAffordHousing saaffordablehousingmag SA Affordable Housing www . saaffordablehousing . co . za