The need for a truss design standard arose following the recommendations that came out of the South Australia Coroner’s Report in June 2005 for the tragic Riverside Golf Club roof collapse in April 2002. The development of the standard, through the Standards Australia Technical Committee structure was also strongly advocated by the South Australian Government.
In February 2011, stakeholders including MiTek, Multinail, Pryda, Forest & Wood Products Association (FWPA) and the Frame & Truss Manufacturers Association (FTMA) met with the standards committee to discuss the development of the new standard.
Peter Juniper, of Juniper Consulting, was appointed as the consultant to work throughout the process, in what has been an outstanding collaborative effort of the frame and truss industry. Joining Peter was Robert Tan of MiTek, Afzal Laphir of Pryda, Matthew Smith of Multinail, Boris Iskra of the FWPA and Nick Livanes, representing the FTMA. Together, the group developed the standard, a document which Standards Australia finalised at their own cost via the TM-010: AS 1720.3 committee.
The foreward in the new AS1720.5:2015 states that; “The design of nailplated timber roof trusses in Australia has evolved over the past 50 years, from simplified manual procedures encompassing standard designs, to the sophisticated computer design packages of today, which are used to individually design each truss within a roof system.
“Over this period, methods of design, fabrication and construction, drawn from research, experience and reference to various Australian and International Standards, have been developed to suit the form and style of Australian buildings. This Standard is the result of a collaborative effort to document a common uniform method of designing nailplated timber
roof trusses in Australia.”
Geoff Stringer, Chair of the Standards Australia TM-010 Timber Structures and Framing committee, said that, “The publication of a design standard for nailplated timber roof trusses adds significantly to the AS1720 timber design suite, and will assist everyone involved with nailplated timber roof trusses to achieve the required performance outcomes.
“AS1720, part five, is the culmination of a great deal of hard work and collaboration by a number of companies, and by the leading timber engineers within those companies.
“We expect that this standard will be referenced within the National Construction Code 2016, and that this will assist in achieving the full benefits a standardised design approach.”
The next step will be to look at the AS4440-2004: Installation of nailplated timber trusses.
Standards Australia will take this standard through the revision process, which will involve a public comment at some stage down the track. The FTMA Australia will ensure all fabricators are kept updated on this process as it develops.
You can purchase your copy of the AS 1720.5:2015 Timber structures – Nailplated timber roof trusses, via the SAI Global website.
BUCKLING UNDER PRESSURE
Over the years I’ve commented on propaganda from the steel industry, who claim their products are stronger than others, environmentally friendly, easier to build with and safer, which of course we know is not necessarily the truth – but as they say, ‘Don’t let the truth get in the way of a good story’.
I also like the other saying, ‘A picture is worth a thousand words’, and I thought readers may like the following picture of a load of steel frames being delivered to site in South Australia, sent to me recently.
The picture shows the frames buckling, which of course automatically weakens the frames. One has to only wonder how this will be fixed when delivered to site; then again, more energy can be used to recycle the product – which surely will go to waste!
NEW KIDD ON THE BLOCK
FTMA Australia welcomes their latest members, Dean and Tammy Kidd, of the newly formed business Kidd Trusses in Dandenong, Victoria. Dean has been a long standing board member of FTMA Australia, representing his former employer Dahlsens (who remain on the FTMA Board). The FTMA wishes Tammy and Dean all the best in their new venture.
For more information contact Kersten Gentle on 0418 226 242.