Finishes for hempcrete - The Hempcrete Topic: Designing and Building with Hemp-lime - page 422

into direct contact with us. The choice of which paint you will use is therefore a very im-
portant one - for the health of you and your family as well as the health of your hempcrete
walls.
As many people will be aware, it is perfectly possible to make your own natural breathable
paints, in some cases using ingredients so easily available that you may already have them
in the house. This option can often be cheaper than buying manufactured paint, and of
course enables you to be 100 per cent sure about exactly what has gone into your paint.
For those interested in exploring this idea further, there are many topics containing natural
paint 'recipes', including Using Natural Finishes and The Natural Paint Book. There are
also courses available on the basic techniques.
The most basic, and minimalist, form of internal finish for hempcrete is a limewash or
breathable paint applied directly to the face of the cast wall. This simple technique is ap-
propriate for those who like the look of hempcrete, and who see value in the simplicity and
'honesty' of leaving materials exposed within the building. In theory the hempcrete could
be left as originally cast, but a couple of coats of natural paint, for example a nice thick
clay paint, will help to protect the surface and consolidate any loose particles of shiv or
dusty areas.
Painted hempcrete can provide an attractive textured wall surface, but remember that when
casting hempcrete there is a skill in achieving a surface with a consistent appearance across
the whole wall. This relies heavily on the hempcrete being placed carefully, and with par-
ticular attention given to achieving an even density on the internal face of the wall. If using
a limewash painted directly on to the hempcrete, at least four coats would be required to
give a solid textured background and cover all the substrate.
Finishes for bathrooms and kitchens
At Hemp-LimeConstruct we are often asked about the issue of maintaining the breathab-
ility of hempcrete walls in rooms such as kitchens and bathrooms, which conventionally
have non-porous finishes such as tiles and waterproof 'bathroom and kitchen' paints.
There are two reasons why the internal wall surface needs to be breathable. The first is so
that the cast hempcrete can dry out properly to both sides of the wall, ensuring that excess-
ive moisture is not retained in the wall. For this reason it is important that hempcrete walls