Hempcrete

A breathable, self-insulating and carbon negative material for use as floor slabs or walls.

hempcrete wall

Hempcrete wall

For use in walls, shuttering is erected either side of the timber frame structure and the hempcrete placed by hand and lightly tamped. The external shuttering is removed after about a day, internal shuttering is often left in place. After about a month the external finish can be applied, which must be breathable, for example lime render. This work should be completed before the first frosts – when working with lime work with nature, not against it!

Hempcrete can also be used as an insulating layer within an existing building. We are working with Native Architects in York on such a project – their press release can be read on their website.

Windows, doors and service ducts can all be easily cast in place. Alterations after placing can also be accommodated as hempcrete is easy to cut and repairs will bond well. Hempcrete has great insulating properties, which are maximised as it dissipates moisture so well.

big green hempcrete machine

Our custom volumetric mixer.

A hempcrete floor slab needs to be placed on to a sub base which will not “wick” moisture. In common with all breathable systems it is important no DPM is used as this would lead to damp problems. The base can be ordinary gravel, or to improve the insulation value of the floor even further recycled foamed glass can be used.

For more information, see our hempcrete factsheet and hempcrete FAQ.

We are now offering a practical knowledge transfer tour, designed for 2 visitors from overseas. Contact us for booking.

You may also be interested in limecrete.