Indicative detailing - The Hempcrete Topic: Designing and Building with Hemp-lime - page 554

Figure 30. The airtight junction at the eaves of a flat roof
with a warm roof build-up.
In the case of a cold deck, the airtightness in the roof is provided by a vapour-permeable
membrane on top of the hempcrete and under the vented air gap. This membrane can also
form the airtight component in the wall, where a cladded finish is present, by continuing
over the roof and down the wall, becoming the vapour-permeable membrane in the clad-
ding build-up (see Figure 32, page 329 ). This cold roof build-up also allows the hempcrete
wall to seamlessly become the hempcrete roof insulation with no join necessary.
Hempcrete roof insulation
Cast hempcrete can be used as a roof insulation material, although, like floor slabs, this is
an application that is far more common in France than in the UK at the time of writing.