Restoration and retrofit - The Hempcrete Topic: Designing and Building with Hemp-lime - page 460

there are significant benefits to the use of hempcrete in heritage properties, which can be
summarized as follows:
Hempcrete works in harmony with, and in a similar way to, original materials in herit-
age buildings, ensuring that the breathable building fabric is maintained.
It is more hygroscopic than wood, so it actively 'sucks' moisture away from timber
frames and releases it into the air, helping to preserve the timber. This is especially im-
portant for frames with externally exposed timbers.
Heritage buildings are not square and not built to today's standard measurements, and
ancient timber frames will usually be quite warped. Wet-mixed hempcrete, being loose-
fill, represents a huge saving in labour of cutting insulation boards to different shapes
and sizes to fit in between the frame structures. In any case, cutting board materials to
fit will never be entirely successful and will leave many gaps in the wall.
Likewise, being loose-fill, hempcrete fills any voids and gaps when cast as solid-wall
insulation against uneven stone walls.
Finishes suitable for hempcrete are the same as for most heritage buildings, e.g. lime
render, weatherboarding, hung tiles, brick or stone.
Hempcrete, as a cast material, makes it easy to retain the curves and lines of original
building, preventing any loss of original character as insulation is installed.
Small amounts of hempcrete can be mixed up and used to fill those awkward small
gaps and spaces that are always found in old buildings: small voids in walls; gaps be-
hind door frames, at the end of joists, and at the top of the wall under the eaves. It's a
breathable, insulating alternative to the menace of expanding foam!