Step 13: Earthen Plaster on Interior Walls

Picture of Earthen Plaster on Interior Walls
curved int window.JPG

Earthen plaster is lowest cost, easiest type of plaster to work with. Many people find earthen plaster very enjoyable work. They’re often pleasantly surprised at how incredibly simple it is. After all, the main process is basically smearing mud on the walls. Follow one of the free recipes on the Internet. Experiment with small patches to help determine the optimum mix for your materials. Add more sand or less water if the plaster cracks. Add more clay if the plaster doesn’t stick to the walls.

The first step is to fill the recesses between bags and apply plaster around doors and windows. Plaster mesh is recommended around all windows and doors to help prevent cracking. You can apply earthen plaster with your hands or with a hawk and trowel. Allow each coat to thoroughly dry before adding additional coats. Leave each coat rough so the next one will more readily bond. Add more coats of plaster until your walls are finished. Smooth the final coat until you’re satisfied with the results.

2nd photo: Here you can see the natural beauty of earthen plaster that's been sculpted to gracefully curve around window and door openings. This not only looks good, but also lets in more light and improves the view. I want to emphasize how this simple concept totally transformed our roundhouse from a bunch of bags into a thing of beauty. Click here for more details about rounded corners. 

Macki2 years ago
Approx how many layers of plaster are needed for this finished looked?
Owen Geiger (author)  Macki2 years ago
Usually three layers -- one to fill the gaps, one to even out the walls, one finish coat. Be sure to allow ample time for each coat to dry thoroughly or moisture will get tramped and crack the upper layers.
Owen Geiger (author)  Owen Geiger2 years ago
That should say "or moisture will get trapped" ...
This is more of a concern than conventional buildings since the plaster is much thicker.
I truly love the look of earth plaster, it's very rich and warm feeling. How often does this need to be patched, usually? And I was wondering, have y'all ever used decorative tile on the interior window sills? And in door surrounds? I have no idea how to get a good bond on earth plaster-the usual methods of installing tile, or something additional or different? I'm a ceramic artist, is why I ask. I thought those would be really pretty touches.