Civil Engineering Reference
In-Depth Information
take hazel stubs, and insulation between the
timbers of the plate. You need to think about
how the walls are going to be compressed if
you are using pre-compression techniques,
and make sure you have made provision for
this. If you are using structural door frames
they should be fixed securely to the founda-
tions or baseplate before the straw is laid,
and any fixing posts for windows and doors
also need to be in place. Window boxes,
as an alternative, are built into the walls as
they go up and are pinned through the base
with hazel. For loadbearing buildings, it is
useful to place temporary braces at corners
and along long lengths of wall to provide a
guide to keep everything vertical.
There are usually some small gaps at the
joints between bales, even after the most
careful trimming and customising, and
these must be stuffed (but not over-stuffed)
with straw after every course of bales
before beginning the next. And, finally,
there is no substitute for climbing on to
the bales and jumping hard between the
strings! This helps with compression (bales)
and depression (humans).
BALE COMPRESSION
Building
The first course of bales must be placed
slowly and carefully, as these provide the
template from which the walls will emerge.
It is important to make sure that the bale
is placed centrally on the baseplate, lining
up with the outside edge of the timber, and
securely pinned by hazel stubs. You must
follow the bale plan accurately, or you might
end up with only a half-bale space left in
the middle of the wall (which is structurally
unsound) as different teams set off from
different corners!
Bales go together like giant bricks, a second-
course bale straddling equally the joint
between two lower bales. Work from fixed
points into the centre of each wall; place
the corner bales first, and those beside any
fixing posts. Make sure that corners are
vertical and don't move as more central
bales are placed. Use a spirit level! Bales
need to be hand-picked to ensure a snug,
not over-tight fit.
Remember to stay calm, work together, and
be aware of what other teams are doing on
their sections of wall.
