People are often fascinated by the structure of my earth-bag home, but in truth, building the structure was the easy part. It’s the plaster that is an art — and a science. It took me only 6 weeks to build my earth-bag house, but almost 2 years to get my plaster sitting beautifully on my walls without cracks or bits of it falling off. At times, I thought it might have even been witchcraft.
It doesn’t have to take that long to learn earth plaster as a natural building technique, though. I was sitting atop a remote hill in Turkey, not receiving the correct information about how to deal with my soil and my climate. After I learned the art of mud rendering appropriate for my climate, it opened up a whole world of possibilities. Now I know it as one of the most useful skills I’ve ever learned.
What is Earth Plaster (What is Clay Plaster)?
Earth plaster (also known as “clay plaster”) is made from a mixture of earth, clay, straw and sand. The clay is the binding element, hence why it’s also called clay plaster. Sometimes other ingredients are added into the mixture for various reasons, perhaps to water proof the plaster or to help it adhere better, or to mitigate dampness. Each stage of plaster creation and application is crucial to success. You need to know how to mix it, test it, and apply it.
Here’s an incomplete list of just what you can do with earth plaster. The beauty of using this medium, of course, is that it’s insanely inexpensive to make things out of mud. Most of the time, it’s free. And if you’d like to know how to make it, I have a free PDF here.
1. Natural Rendering for Buildings
The most obvious use of earth plaster is as a natural render. Render is crucial for any house, as it protects the main structure from weathering. What a lot of people don’t realise is just how many different surfaces you can successfully render with earth plaster: stone houses, straw bale homes, cob, earthbag, and even wood (wood requires some preparation, but can definitely work).
Earth plaster doesn’t work well with mainstream building materials, such as Portland cement and plastic, though, as they are not breathable.
2. Wall Sculptures (Pargeting)
Pargeting is both decorative and known to form a stronger protection against weathering. One of the things I most enjoyed creating out of earth plaster were my wall sculptures. By slowly working the plaster with your hands and tools, you can form any shape you like.
3. Mosaic
Earth plaster works amazingly well with mosaic. You can inlay broken tiles or glass into the plaster, then buff it smooth with newspaper or a leather cloth to create beautiful and hard-wearing results. Mosaics on walls form an almost impenetrable surface which protects against rain.
4. Bottle Walls
By using earth plaster as a natural cement, you can create gorgeous bottle walls. The bottles actually add structural strength to the wall, while the earth plaster grips them and holds them in place. The opening photo shows a good example of the process.
5. Alcoves and Nooks
Alcoves are perfect for holding candles and lighting. Book nooks are beautiful when crafted into an earthern wall. Alcoves can be created either by scooping out earth plaster from a rendered wall or by slowly building up the plaster around a space. Or, as I did, you can use a combination of both techniques.
6. Shelving
Never again do you need to suffer (or cause others to suffer) a drill-induced headache when putting up a shelf. Earth plaster shelves are so easy to make, and they never come loose. By building up the plaster layer by layer you can form incredibly sturdy spice racks, book shelves and more.
7. Inlay Mirrors and Other Decorative Features
Interior design is a whole new ball game when you use earth plaster. Mirrors and pictures don’t need to be hung, they can be incorporated into the wall for a clean, graceful look.
8. Make a Cob Oven
Cob ovens are all the rage at the moment. The word “cob” comes from South West England, and was used to describe the shape of the balls of earth plaster people used to build their homes with. If you know how to render a wall with earth plaster, you can just as easily make a cob oven from the same mixture.
9. Use It as Mortar
People have been using earth plaster as a mortar for millennia. Most ancient stone houses are mortared with mud. Later in Europe, the Romans introduced lime and limecrete instead. But many old stone homes all over the world still have their original mud mortar. By changing the consistency of the plaster slightly (generally you use a softer, wetter version for render, and a dryer, firmer, more clay-ey mix for mortar), you can use your earth plaster to cement rocks in stone walls and other structures.
10. Use It as a Daub on a Lath (Wattle and Daub)
Wattle and daub is another traditional building technique enjoying a bit of a revival. You can create houses by building a post and beam structure, and then fixing woven willow (or similar) laths where you want the walls. These laths are subsequently covered, layer by layer, with…you guessed it, earth plaster.
If you’d like the Perfect Earth Plaster PDF, or to take my FREE mini email course on how to make earth plaster, click here.
Atulya K Bingham is an author and natural builder. She lived semi off-grid in Turkey in her beloved earthbag house for five years, before recently having to leave. She is now on the road searching for a new space to build. Atulya is author of The Mud Home website, which offers plenty of earthbag and natural building information, a window into Atulya’s off-grid life, sustainable living tips, and much more. Read about Mud Ball, Atulya’s popular memoir of building her earthbag home.
All MOTHER EARTH NEWS community bloggers have agreed to follow our Blogging Guidelines, and they are responsible for the accuracy of their posts. To learn more about the author of this post, click on their byline link at the top of the page.
