Picture of Making Straw Clay Plaster: Together, Easy, and Fun!
Hello! This is a tutorial on how to mix an extremely sticky, high insulation straw clay-plaster using local, natural, and bio-degradable materials. This tutorial will cover the elements necessary to mixing a flexible, durable, and long lasting plaster. This tutorial will also give opportunities for you to work together with your friends, family, or a random anybody who likes getting dirty in sticky mud! In the end you will have created a type of natural adhesive that is sculpt-able and insulating.

Things you'll need:

- 2-3 Friends who like to dance in mud!
- A 2 meter x 2 meter square tarp. A 3mx3m will also do if you would like to mix more with more people!
- 2 shovels (or however many people would like to dig)
- 2 pairs of wet-resistant rubber boots
- 2 x 5 gallon buckets of sand*
- 2 x 5 gallon buckets of clay* (this is the sticky stuff!)
- 2 x 5 gallon buckets of water
- 1 straw bale
- 1 wheelbarrow for transporting the mix

*In most places, you can just substitute sand and clay for abandoned soil. Most soil is very rich in sand and clay along with many other useful sticky elements that help stick the plaster together. So just dig a hole anywhere if you do not have access to sand or clay. Check out the Gardener's World site under References to see how you can find out what is in your soil.


The Natural Building Blog: http://naturalbuildingblog.com/
Straw Plaster and its Uses: http://www.earthsweethome.com/plaster.htm
Earthened Homes from around the Earth: http://naturalhomes.org/
Soil Composition and Formation Information: http://nerrs.noaa.gov/doc/siteprofile/acebasin/html/envicond/soil/slform.htm
The Hungarian Permaculture Forum: http://www.permaforum.hu/permablog
What kind of soil do you have?: http://www.gardenersworld.com/plants/features/structural/find-out-your-soil-type/1118.html

Next step: Preparing the mix...

Bard1 year ago
I wonder if one could substitute the hay for paper shreddings
Attila-RT (author)  Bard1 year ago

Yes you can substitute with paper shreddings, celulose, or any other "mesh"-like insulating substance! :)

AtomRat2 years ago
You have mentioned that this can be used around a rocket stove.. How do you think this mixture could hold up for a kiln / furnace if you added some: bentonite, fire clay / reflux cement etc? And I am meaning if it was used completely in the process.. making the bricks and cement.

Excellent instructable, the 'burito' technique for testing the mix is great, and I feel sorry for the blokes stomping about.. you have a mention of no machinery.. if it's not too late, I'm sure the blokes can figure out how to hook a system up to a car, tractor, bicycle..etc

Take a look at the start of this vid here:

Theres a nice idea of a mixing / mashing machine maybe in the first minute or two. If they can weld, and tractor nearby, that's the way I would go.
Attila-RT (author)  AtomRat2 years ago
Hello AtomRat! Thank's for the helpful tips and the video!

If you fired this mix you would probably have a very fragile or grainy result. However, if you mix it with bentonite or fire clay then it would definitely be much stronger. If you were to use bentonite you would not have the need for the straw in the mix because bentonite is quite a solid binder.

One of the main concerns we are having with structures made from cement/concrete is that they are difficult to take a part. If we wanted to, in the future, take a part a structure and use the materials for something else we would not know what to do with a giant concrete/cement rock. So we have found it to be much more useful to use materials that are easily degradable and can return to the earth without much energy.

"One of my favorite things to do is to take a part an entire house with just a hammer"

This machine seems very interesting. Do you think horses could do the work better maybe? In the case of making plaster, not paper, of course. :)

I was thinking for the machine to be used for mashing the clay, mud and straw mixes out there in the bush. And of course they could be horse driven, by using something connected like an olden days horse mill:


( sorry very small image, but this should give you the idea, just from a quick google search )

This is only off the top of my head without researching, but it seems the best way that I would go myself. And make the gears, everything, from big wood slabs and bits of beaten metal belts to hold parts in place ( blacksmithing ).

If you study the video, you can see that the machine is really very simple, one axle, 3 offset 'knockers' on that, and they hit 3 free-standing planks that fall back down with the force of their weight and momentum to crush the soft materials beneath.

..Actually, maybe on a further thought.. A machine like this could just make a blob that would get stuck on the end of the plank and not do anything at all. I suggest google, if you need help, feel free to ask as it is interesting.
wire-nut2 years ago
It just cool, great think. And using what you have on hand. :-)
Attila-RT (author)  wire-nut2 years ago
Thank you! :)