Civil Engineering Reference
In-Depth Information
Nail the head and sill onto the stiles so that they cover the end grain of the stiles. This
allows for any weight on the window buck to be cleanly transferred through the window
buck. In this application the nails are simply there to hold the buck together rather than
to be the primary structural component of the connection (see Figure 5.8).
Once the window buck is assembled, another piece of timber the same length as the
head is to be nailed onto the head of the window buck. You will now have a rectangle
with double thickness of timber at the head, or top of the window buck. A timber brace is
to be fitted inside the window buck diagonally from one corner to the other to hold the
buck square. If this is not done, it is likely that the window buck will be pushed out of
square as the bales are laid around it, and then the window will not fit into the opening.
While it raises other issues regarding flashing, if you are going to lay bales over the
top of the window buck, it is easier if the buck is centrally located in the wall. This will
give you greater stability, as the bales are less likely to twist on top of the buck. When
bales are laid over this style of window buck, the pressure during compression of the
bales will be transferred to the ends of the bottom of the window buck, known as the sill.
As previously detailed in Chapter 4 on straw bale walls, avoid the situation where the end
of the buck sill is aligned with a vertical joint in the row of bales. If the end of the sill is
aligned with the end of a bale, it is highly likely that the sill will compress into this area
more than in the body of the bales (see Figure 5.8).
Figure 5.8
Small window buck with an internally fitted diagonal brace, installed into a straw bale wall
Fitting a simple window buck
Lay the bales on the bottom boxing as previously detailed until you have the required
number of bales below the window. Position one of the pieces of timber for the sill on top
of the bales. This timber is to be used to compress the bales below the window. If you
need additional height to further elevate the bottom window, increase the depth of the
