Mixing hempcrete - The Hempcrete Topic: Designing and Building with Hemp-lime - page 339

You might find that the required amount fits neatly with the bucket size, for example
'three full (level) buckets of hemp' - in which case you don't need to mark the line.
Any colour of marker is hard to see on a black plastic bucket, so use buckets of a light
colour, such as yellow or orange, and mark the lines in black pen. Remember to re-
draw your lines if they are starting to wear off.
You can use the same buckets for the dry loose hemp and binder powder, with two dif-
ferent lines drawn, but keep separate buckets for water. Measuring binder and hemp in
wet buckets results in lots of it sticking to the inside of the bucket, thus reducing accur-
acy.
Plastic buckets have a limited life: check them regularly for cracks and leaks, especially
the water buckets. If they spring a leak, either bin them straight away or make them
into a 'hemp-only' bucket, as hemp doesn't spill out through a crack or tiny hole. Write
HEMP on them in big letters so there's no confusion!
Method and mixing process
Choose your mixing site according to the factors already described for using a pan mixer
(see page 196 ) . Keep the mixing area clean and tidy, disposing of binder bags in such a
way that they are not spreading binder dust around the site.
Ensure you have a good supply of materials close to the mixer. Empty several bales of
hemp into the bulk bags for ease of access. Stick your hands in and shake the hemp about
to loosen it up, as it is packed very tightly into the bales. It's useful to have a large Gorilla
Tub full of water set aside that you can quickly dip into when you need a bit of water for
both wetting and cleaning the mixer.
Follow the supplier's instructions for mixing exactly, but in general the process of mixing
is as follows (see also photos overleaf):
Put on goggles and mask, waterproof clothing, gloves and waterproof boots.
Pre-fill all your marked buckets with water, binder and hemp so that the precise
amounts you need are already measured out before mixing begins.
First, you need to wet the mixer, otherwise the (rather dry) mix has a tendency to cling
to the sides and make thorough combining difficult. Dipping into your 'spare' tub,
throw a bucket of water into the mixer, let it run a bit, and then empty it out.