Hemp in construction - The Hempcrete Topic: Designing and Building with Hemp-lime - page 44

Hemp-fibre insulation, in particular, provides additional environmental benefits. Thanks to
the levels of carbon dioxide taken up by the hemp when it was growing (faster than wood,
as hemp creates a woody stem in just months), hemp-fibre insulation can, like hempcrete,
lay claim to having negative net carbon emissions - locking away more carbon in the
product than was used in its production and manufacture. The production processes, ac-
cording to manufacturers' literature, use significantly less energy than that for synthetic
insulation products. 6
The strength of the hemp fibres gives the insulation quilt a natural durability that allows it
to keep its structure well over time, compared with synthetic insulation quilts, which often
sag as they age and can collapse into a thinner layer in the presence of moisture, resulting
in reduced insulation performance. This self-supporting structure makes hemp fibre suit-
able for warm lofts (insulating between the rafters) and even, according to the manufactur-
ers, for use in timber-frame walls.
Hemp-fibre quilt insulation.
The cell structure of the fibres, combined with the low density and open structure of the
quilt, allows hemp-fibre insulation to attract and hold moisture from the surrounding atmo-