Some of the longest span prefabricated timber roof trusses ever built have been used in a large South Australian aged care facility at Gawler north of Adelaide.

Pryda expertise and equipment were brought together by Keith Timber to successfully make the roof trusses.

Builders of the facility, Warburton Nominees, approached South Australian Pryda fabricator Keith Timber Group to supply the roof trusses for the approximately 80-bed facility. It is a two-storey building where the first floor was supported by a suspended concrete slab with timber wall frames.

All roof trusses had to clear the entire span of the building with no other means of support as there were to be no internal bearings incorporated into the building design.

In the end there were seven sections of trusses involved in the construction. Three were contained roof trusses measuring 19m to 23m long and 4m high, while the remaining were a more manageable nine to 11.5m.

Having recently installed a Hundegger fully automated saw and Pryda C4 table press, Keith Timber Group were well positioned to cope and construct the super long prefabricated timber roof trusses.

The giant prefabricated trusses were designed using the latest Pryda Build i software. This enabled to roof truss configuration to be seen in an interactive revolving 3D landscape that greatly increases detailer efficiency.

With consultation by Melbourne Pryda engineers, the large span trusses were strengthened using double or triple 35mm thick timber. Bigger nailplates and changed web profiles were used to meet the demands of the bigger truss construction.

Keith Timber truss detailer Steve Hancock said, “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.

“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.”

The trusses were transported from Keith to Gawler using extendable trailers and wide load escorts. The Adelaide-Melbourne highway was closed at Murray Bridge town to enable the trucks to pass safely over the bridge.

Once on site, the trusses were lifted using a 16m spreader bar and multiple slings to maintain their integrity.