Civil Engineering Reference
In-Depth Information
Calculating the lintel height
To establish the likely height that the lintel is to be, calculate the overall height of the
straw bale walls including the bottom and top bale boxing. Deduct 7 per cent for
compression. It is likely to be less than this, however work with 7 per cent. This is
the required height of the top of the lintel to the surface of the floor, which will result in
the top boxing finishing higher than the lintel (see Figure 5.14).
Top
b
oxing
Lintel
Dropper
Figure 5.14
Dropped rolled head dropper joining the top boxing and window lintel for load bearing construction
Lintels supported on 100
×
100 posts
The lintel is supported on posts, normally 100 × 100. The lintel will either be checked
into the post or bolted to the face of the post. There are a number of factors that will have
a bearing on the construction system most appropriate for your house. I suggest that you
initially discuss this with your building consultants; if it is beyond their capacity to
determine the appropriate application you will need to refer this to your engineer. Fit the
lintel to the post with them lying on the floor. Fit a piece of timber from one post to the
other at the bottom of the posts so that the posts are fixed in a parallel position. With the
posts, lintel and cross timber still laying flat on the floor ensure the structure sits in a
square position by checking that the diagonal measurements are equal. Once the
structure is sitting in a square position, fit a diagonal brace within the structure to
prevent it from moving out of square.
The posts should not be greater than 140 mm deep. Fit a piece of timber horizontally
between the posts halfway up the posts to prevent the posts being bowed inwards as the
bales are laid. Stand the post and lintel up in the correct position and hold it in place with
braces to the floor or pegs in the ground outside the building envelope. The lintel is
positioned in the wall so that the inner edge of the top bale boxing when positioned on
the bales will rest against the outer edge of the lintel. The edge of the lintel facing the
outside of the building will normally be 135 mm from the inside face of the bales.
