Civil Engineering Reference
In-Depth Information
To assemble the first truss, lay out all the members and place a bolt through all of the
joints except the first joint to be fitted with a connector. At this first joint (probably the
rafter to ceiling tie joint) fit the specified connector and, using a special high tensile steel
stud available from the connector suppliers, pass this through the bolt hole in the joint and
place a large 100 mm square × 6 mm thick steel spreader washer on both sides of the joint.
By turning the nut, bed the connector fully home. Considerable pressure is needed to bed
the double-sided tooth plate timber connector, and the mild steel bolts used to maintain the
joint in the final assembly are not adequate for three reasons: firstly, the pressure required
may well strip the threads from the mild steel bolts; secondly, if several connectors occur
on the same bolt line there is unlikely to be adequate length of thread on a standard bolt to
pull the joint down embedding all of the connectors (Fig. 4.1 illustrates this). Thirdly, the
smaller 50 mm × 50 mm × 3 mm thick mild steel washer used with the standard bolt will
be inadequate to protect the timber surface from crushing and may itself be severely dis-
torted. Where two or more sets of connectors occur, such as the ceiling tie to ridge strut
joint on Fig. 4.3, the appropriate number of high tensile studs will be required to pull the
timbers down progressively if severe distortion of the timbers is to be avoided, as illus-
trated in Fig. 4.1.
When the connectors are fully embedded the high tensile stud can be withdrawn leaving
the joint generally well held together with the connectors. The standard bolt may now be
inserted in the joint with the 50 mm square washers under both head and
