Hempcrete is a robust building material. For older houses and renovations, it is cast around existing timber studwork, therefore contributing strongly to the diagonal bracing or racking strength requirements of the frame. Hempcrete can be placed behind common exterior weatherboards, the lime binder inhibits timber rot and stabilises the timber frame, effectively preserving it.
Hempcrete also works well with standard brick veneer houses. The internal plaster and existing insulation is removed, the hempcrete is placed to fill the cavity; from the internal brickwork all the way back to the internal wall line. This creates tremendous future energy savings. Hempcrete teamed with exterior masonry works very well and is in fact the major application of hempcrete in Europe. On jobs I've worked on in the UK, Hempcrete was often adhesed internally to old stone walls for barn conversions.
Hempcrete also be retrofitted externally onto existing walls if existing eave size and design permits. In this case a lime render is applied to the external face of the Hempcrete.
All are fantastic options for creating a complete thermal envelope of the house, substantially increasing energy efficiency.
For houses with issues with damp, hempcrete can help to disperse and diffuse moisture. As opposed to dry walling where a false wall is ‘packed out’ to hide the damp issue
You could negate all your gains from a lifetime recycling and bike riding to work just by building a new house. A new build carries a carbon footprint of between 50 to 80 tonnes. Retrofitting or renovating your home not only looks great but also carries a huge carbon saving.
