Tuesday, November 10, 2009

Types of hemp for building

Thanks to Deb and Pili for drawing my attention to the need for some basic info. And thanks to all the readers of this blog, which has had over 10000 hits now. The hemp we use for builiding is the centre part of the stem, after the fibres are removed. They're called the hurds. There are three types of hemp for building that I know of. Building type such as St Astier sells, which looks like wood chips, the particles are clean and pretty uniform, and around 1cm. The Horse bedding type is rougher say up to 3cm, but varied and may contain bits of fibre, and the odd seed or leaf. As I understand, this is what's left from a high quality fibre extraction. I use this for building. It binds together nicely, goes on thickly, and gives a prety good insulation. You can work it very smooth, see Neil's work on these pages. alternatively if it looks too bumpy, pop a smooth lime and sand coat over the top. The third type of hemp is a 2mm screened fibre, left over from cloth making I suppose. This is whats in Hempire skim coat. You can use anything in lime plaster that will resist cracking, in the past people mostly used horse hair, but occasionally straw, or jute. Goat and human hair are ok too. Someone tried nettle fibres, with an ok result. Hemp is just todays waste, so this is a handy use for it! Good luck

1 comment:

Gary said...

I have just planted 50 kgs of hemp seeds in central Laos and expect to harvest December time. I want to use the hemp for building a house. From other sources, 50 kgs is enough to plant 6000 Sqm.

I would like to know;
1. at what stage to harvest( ie before or after flowering/going to seed),
2. how long to cut the stalks,
3. mix of the lime binder. Is it just hydraulic lime or mixed with sand or other?
4. Lime binder to hemp stalk mix ratio.
Commercial lime binders are not available in Laos and I want to do myself.

Any other sources of information would also be appreciated.

Best Regards,
Gary T. Wight