Performance of hempcrete in a building - The Hempcrete Topic: Designing and Building with Hemp-lime - page 135

crete provides racking strength to the frame structure - adding significantly to its ability to
resist lateral movement as a result of external forces, such as wind loading - and thereby
removing the need for the timber diagonal braces traditionally used for this purpose. In
fact, according to Amziane and Arnaud, the hempcrete infill provides almost ten times as
much racking strength to the frame than does timber diagonal bracing. It also significantly
reduces the amount of deformation the structure exhibits in the event that the frame does
eventually break.
In construction practice, this ability of hempcrete to brace a timber frame has the advantage
of reduced timber requirements (in terms of the number and size of diagonal braces, as well
as the number of horizontal noggins for general rigidity). It also reduces the time spent on
frame construction, since the diagonal braces are the most time-consuming frame element
to construct and fit.
As hempcrete is a non-load-bearing insulating material cast around a structural frame,
building control inspectors have little interest in it from a structural point of view, simply
requiring that it meets fire regulations, levels of thermal performance, and acoustic insu-
lation requirements as mandated by the relevant Building Regulations. However, when it
comes to convincing building control inspectors that reinforcing and bracing frame mem-
bers can be omitted from the structural frame, as the hempcrete provides this function, they
start taking more of an interest.