Roof Lines & Trusses Flashcards
When using AS4440, what is the maximum span of a roof truss?
16m
What is the maximum roof pitch for a roof truss?
45 degrees (100:100)
What is the maximum spacing of a roof truss for standard and lightweight roofs?
1200mm lightweight roof
900mm tiled roof
What is a camber in relation to a roof truss?
Curvature built into a truss intended to compensate for the long term deflection
due to dead loads.
What is a Girder truss?
A truss that supports other trusses or beams
Where is the span of a truss measured from?
Pitching point to pitching point.
What distance must a non-loadbearing wall be from the underside of a truss?
10mm
When fixing trusses to free standing non-load bearing walls, which are braced,
and how far should the nail be driven in?
Not fully through internal wall bracket to allow for vertical movement
Where internal non-loadbearing walls are required to resist normal applied force,
how far apart can the top plate of the wall be stablised?
1800mm - Not fully through internal wall bracket to allow for vertical movement
What are some of the reasons trusses can be rejected and returned
to the manufacturer for rectification?
1a - Split timbers
1b - Nailplates missing
1c - Nailplates misplaced
1d - Nailplates evidence of flattening teeth, excessive timber splitting
2 - Truss support incorrect position
3 - Fault discoverered after truss has been loaded
What is the maximum distance a girder truss can be set off the external corner?
3600mm
What is the common name for steel bracing that goes across the top of trusses?
Speedbrace
What is defined as a station as per AS4440?
The position of a truncated truss, a truncated girder truss or a Dutch-hip girder truss
measured from pitching point to near face of truss
