Pryda and Keith Timber are manufacturing of some of the longest span prefabricated timber roof trusses ever built. These are for a South Australian aged care facility at Gawler north of Adelaide. Source: Timberbiz
Earlier this year, builders Warburton Nominees approached South Australian Pryda fabricator Keith Timber Group to supply roof trusses for a two-storey building where the first floor was supported by a suspended concrete slab with timber wall frames.
The proviso was that no internal bearings were to be incorporated into the building design, so all roof trusses had to clear the entire span without any other means of support.
Seven sections of trusses are involved in the construction process, three measuring a massive 19 metres to 23 metres long and four metres high, while the remaining sections were nine to 11.5 metres.
Design of the giant spans was carried out using the latest Pryda Build I software, which enables the roof truss configuration to be seen in an interactive revolving 3D landscape that greatly increases detailer efficiency.
Keith Timber Group consulted closely with Melbourne Pryda engineers who suggested strengthening each large span truss using double or triple 35mm thick timber. The company also used bigger nailplates and changed web profiles to meet the demands of the much bigger truss construction.
“Pryda engineers recommended off panel point splices that allows chords to be flipped end for end where possible to offset splices within the laminated truss,” explained Keith Timber truss detailer Steve Hancock.
“The trusses were so large that each one had to be individually and manually manufactured on the press using the whole table, which normally is set up for two jobs at a time.”
