6m must tied the building give
them stability.8
A trestle scaffold.
Trestles which are higher than 3. The maximum span boards between trestles is:
● 1.3m for boards 40mm thick
● 2. Two pairs trestles spanned scaf-
folding boards provide simple working platform.
TRESTLE SCAFFOLD
Figure 8. least one-third the trestle must
be above the working platform. The tower built slotting the sections
together until the required height reached.
.5m for boards 50mm thick.
MOBILE SCAFFOLD TOWERS
Mobile scaffold towers may constructed basic scaffold components
or made from light alloy tube. 8.
FIGURE 8. The platform must be
at least two boards 450mm wide.Basic Electrical Installation Work
168
Safety First
Scaffold
● scaffold mobile towers are
always safer than ladders for
working above ground.
Start position
Footing
base of
ladder
Lift and walk
towards wall
Continue until
upright
FIGURE 8.5m from the working
platform, trestles may not used.9.7
Correct procedure for erecting long extension ladder. scaffold tower shown in
Fig. the platform more than above the
ground, toeboards and guardrails must fitted, and separate ladder
provided for access. The boards which form the working platform should
be equal length and not overhang the trestles more than four times
their own thickness.8 shows trestle scaffold. Where anyone can fall more than 4
