How to Install Earth Plaster Over Straw Bale

Earth plaster is a plaster made from the earth and is also known as adobe. Straw bale houses can be covered with earth plaster for a very reasonable cost. Earth plaster is also ecologically friendly. Earth plaster is usually made from scratch by the homeowner, but there are some companies that sell the earth in bags. Here are some tips to help you install earth plaster over straw bales.

Difficulty: Moderately Challenging

Instructions

1. Research the types of earth plaster commonly used for straw bale. Use the internet, visit the library and find bookstores that carry books about straw bale houses and earth plaster. Learn as much as you can, but remember, the mix used is generally an individual's choice. Some people add straw to the earth and others add lime.

2. Mix a batch of earth plaster after your research and practice with it. Most earth plasters are made of clay, sand and silt. Use a straw bale and apply the practice mix to it. Add more or less water and find the easiest method for you to apply the earth plaster. Find what is comfortable for you before starting the whole project. Use a trowel for the last coat for a finished appearance.

3. Write your recipe down after you've experimented with it. Most contractors add straw or wool to the earth mixture to add stability to it. Adding fiber to the mixture also helps decrease cracking in the mud mixture. Amend the soil as needed; add sand if the soil has too much clay. Remember to screen the soil so it is free of sticks or pebbles.

4. Use hardware cloth on top of the straw bale to help the earth plaster stick. Many people feel this step is unnecessary when applying plaster to a straw bale because the straw itself helps the plaster stick. Do your research and test it yourself to decide.

5. Apply the first, or base coat, of earth plaster to the straw bale. The first layer needs to be thick enough to cover the straw, but not so thick that it will fall off. The first coat helps level out the surface. Allow the first coat to dry before applying the next layer. The earth plaster will adhere better if applied in two or three layers.

6. Finish the earth plaster with an alis. An alis is a powdered color that is added as a wash to give the earth plaster a finished look.

Resources

• Check out the earthen house at the Do It Yourself website.
• Mother Earth News has more information about earth plaster over straw bale homes.

[natoma520]

on 4/4/2008 for an excellent example of a strawbale home with both earth and lime plaster, check out www.buildingwithbales.com

It gives pics as well as some detail about mixtures and applications