Restoration and retrofit - The Hempcrete Topic: Designing and Building with Hemp-lime - page 474

The same wall with hempcrete in place.
Solid-wall insulation on masonry buildings
Hempcrete can be cast straight against masonry walls to add insulation. This can be done
either internally or externally, depending on the requirements of the situation.
If the wall has been pointed or rendered with cement, or plastered with gypsum, these
should be removed (in the case of cement) or hacked off (in the case of gypsum plasters),
with pointing replaced with a lime mortar appropriate to the type and condition of the ma-
sonry. If pointing is lime and in solid condition, it can remain. It is important to give the
wall sufficient time to dry out fully before casting hempcrete.