283757893275

A timber profile is cut to the same dimensions as the
steel base plate. Holes are also positioned in the
same position as those in the steel base plate
The profile (timber base plate)
is fixed to a temporary timber
frame, which is securely pegged
into the surrounding ground
The horizontal profile must be
fixed at the correct level
The holding down bolts are then inserted
through cardboard or polystyrene cones
and bolted to the timber base plate
The profile is then fixed to a
timber frame and held at the
correct position so that the
concrete can be poured
around the bolts
Cardboard cones will
form void in the
concrete allowing a
tolerance so that the
column can be fixed in
the correct position
Hole excavated ready for
concrete foundation
Rather than fixing the bolts to a
temporary frame, the bolts, which
are fixed to their timber profile
(base plate), can be simply
positioned in the concrete at the
correct line and level; this is
called floating the bolts. If
floating is used, the position and
level of the bolts must be checked
Figure 5.43 Temporary bolt boxes.
The bolt boxes are held in position by a temporary timber frame and checked for line
and level. Once the concrete is poured the bases are checked for line and level again
Photograph 5.10 Positioning of holding-down bolts – bolt boxes (courtesy of G. Throup).