Finishes

Don’t be mistaken in thinking your hempcrete home will look like a grass hut. Hempcrete is an ideal background to apply a variety of finishes. Whilst the finishes must be natural to maintain breath-ability, the application of plaster and render give a smooth, clean and modern finish.

There are two categories of finishes: wet applied finishes and cladding.

Wet applied finishes

Lime, clay and earth are all vapour permeable. These are available commercially or for the adventurous they are available as ‘raw’ materials which extra strength can be added to plaster finishes such as hemp shiv, chopped straw or mesh and can be coloured with aggregates or natural pigments.

Lime and clay finishes can be used internally and externally and both can be buffer moisture in response to the indoor humidity. Lime works well as an external render with a hard finish to withstand weathering while retaining vapour permeability. As shown in the accompanying photograph of a beautifully finished lime rendered home in Israel designed by www.tavgroup.com.

When building sustainably paint finishes on internal and external walls ideally are to be natural and with lower embodied energy and low in harmful VOC’s (volatile organic compound) but for use with hempcrete walls the most desirable attribute is breath-ability - permeability to moisture vapour. It is contradictory to seal up your beautifully created permeable wall with synthetic paint. Truly breathable paints will usually be mineral based, often lime or clay. Limewash is also a very cost effective option but it can be more temperamental than paint and therefore is best suited for external walls with natural paint for internal walls. Limewash has a natural milky-white colour or you may tint it with natural lime-tolerant pigments such as ochre or sienna.

Cladding

Typically for reasons of simplicity and low material cost the first choice for an external finish on a hempcrete wall is a lime render, however there are times when an alternate finish is required. For example, orientation or exposure, to create a feature wall or for contrast in materials, cladding can be successfully used whilst maintaining hempcrete wall specific characteristics.

Cladding on a hempcrete building is much the same as on other buildings such as timber boarding, stone or brick masonry and creates a stunning decorative finish.

Natural renders provide a welcoming, warm and aesthetically pleasing finish to a modern home.