Civil Engineering Reference
In-Depth Information
Wall heights
Securing two-storey straw bale walls back to the infill structure
Wall heights up to three metres present few complications, beyond this lateral stabilising
will need to be supplied. When constructing a two-storey house this stabilising can be as
simple as tying the bales back to the upper floor joists. Drill holes in the upper floor joist
through which you will feed polyester strapping. The strapping is to be fed through holes
in the floor joists and then out through the straw bale wall. Thread a piece of twine into
the hole of a single bale needle then push the needle through the straw to the outside of
the building. Tie the twine to the polyester strapping and pull the strapping from the
inside of the house to the outside. Repeat this procedure to feed the polyester strapping
from the outside of the house back to the inside. This will form a loop of polyester
strapping on the outside of the bale wall. Slip a piece of timber, ideally 35 × 35
approximately 400 mm long inside the loop of polyester strapping on the outside of the
wall. Pull the excess strapping to the inside of the house so that the timber cleat is held
firmly against the bales. With the strapping fed through the holes drilled in the floor
joists, the tensioning tool can be used to tighten the strapping (see Figure 4.3).
Figure 4.3
The intermediate securing of straw bales to the upper floor joists to prevent the 4.2 metre wall from
toppling over during construction
Sufficient tension is to be applied to the strapping to cause the timber cleat on the
outside of the house to be embedded into the straw bales. It is essential that the strapping
be fed through several of the deep floor joists. If the strapping were secured to a single
floor joist the tension applied to the strapping would cause the floor joist to twist and
bow out of its correct location.
