Design fundamentals - The Hempcrete Topic: Designing and Building with Hemp-lime - page 520

Awkward placing
When it comes to placing hempcrete, awkward sections can arise anywhere that is not a
simple straight run of wall. This includes areas around openings, at corners and at upper
floor levels where floor joists may extend into the wall. These areas all require more tim-
bers and brackets within the wall, for example where corner studs or studs around open-
ings are being reinforced with noggins (horizontal timbers - see below) or where joists are
fixed. The more structural elements in the wall, the harder it will be to place the hempcrete
around them evenly and neatly.
Care should be taken at the detailing stage not to put too much 'stuff ' in the way of hemp-
crete being placed, especially where a permanent shuttering board is being used and the
wall is therefore accessible only from one side. Every time something is detailed within
the wall, the designer should ask “Can hempcrete easily be placed around this?”
Horizontal timbers
Noggins - horizontal timbers connecting and supporting adjacent studs or joists - within
the frame should be reduced to the absolute minimum. Noggins may be required in some
instances, for example at door openings to reinforce the stud that supports the door case-
ment, and the same may be true for large windows, corner studs and also at joins in the
permanent shuttering board if one is being used. They are also commonly used as a support
on to which back boxes for electrical fittings are screwed (see also Chapter 13, page 164 ).
Apart from such critical situations, horizontal timbers should be avoided, as they make it
difficult to get the hempcrete beneath them. To do this the contractor would have to reach
down into the shuttered section of the wall and try to stuff the hempcrete under the tim-
ber. It is common to see voids under these horizontal timbers when the shuttering is struck.
This is not the end of the world, since these can be filled with more hempcrete, but this
process is time-consuming and should be designed out as far as is possible.
Where a horizontal timber is absolutely necessary, specifying a triangular section timber
(such as arris rail, or a ripped-down 50mm x 50mm timber) can make life easier. These
might not be suitable as structural timbers, but could be used for non-structural applica-
tions such as supports for fixings or at the joins of permanent shuttering board (see Figure
20 ) .