Civil Engineering Reference
In-Depth Information
positioning of the corner bales (see Figure 4.5). It is essential that the bales be placed one
on top of the other in a vertical line. If not, the wall may bulge and burst out one side
during compression. This is particularly important for load bearing walls, as the weight of
the roof and ceiling is transferred through the walls and floor down to the foundations.
Figure 4.5
The use of a corner bale guide will help to keep the corner bales vertical and in line
Top bale boxing
Options for top boxing
The top bale boxing again varies between different builders. It is suggested in one book
that steel be used, while another recommends that the top boxing be of timber and
extend beyond the width of the bales. As previously mentioned, apart from my
reservations regarding the reliance on render for support of the roof, if the job calls for
this, then I do not have a problem with the use of top boxing that extends beyond the
width of the walls. However I have more than a little difficulty with the concept of metal
top boxing. For an owner-builder to assemble timber top boxing is simple, however this
is not the case with metal. Apart from the cost and likely failure of the welds in this
system I would rather not introduce more steel to the structure than necessary. I would
expect building surveyors to demand that a certified welder carries out all structural steel
fabrication, as it will form an integral part of the construction.
Preferred, proven and easy-to-build timber top boxing
For several years we have been using top boxing that is 180 mm wide, which roughly
matches spacing of the twine around the bales, which vary from about 180 to 200 mm
