Rammed Earth Construction, California

Hi All,

I am looking for Rammed Earth Builders in the CA Bay area in addition to advice from anyone with experience using this material.

Our project is a small 100SF backyard office with a landscape wall extending across the client’s rear yard. The office is sunken 2’ into a hill so a portion of the walls sit in the ground. We are hoping on using Watershed block below grade to further reduce cement (any experience/advice with this product is welcomed).

  1. How can we design the walls to minimize cement use?

  2. In addition to a roof, what are the methods for waterproofing RE?

  3. In our Bay area climate, how well would a 4’ RE landscape wall survive the winters unprotected (no roof)?

If anyone has time to talk through these and other questions, please let me know!



Hi Brian, my company specializes in clay based material engineering and we’ve worked regularly with rammed earth and watershed blocks as well as cob, adobe and other clay structural wall systems. I’m happy to answer any questions you have, feel free to reach out via my contact info below. Though I can answer some of your questions here.

Bay area builders: You obviously know of Rammed Earthworks who are excellent, and there are other natural builders in the area with rammed earth experience including Massey Burke. I could likely generate 3 or 4 other names.

Cement/stabilization has a lot to do with the rest of your questions. Most convectional rammed earth contains a notable amount of cement or asphalt emulsion stabilization. This is not required though has it’s practical benefits as cement usually does concerning structural characteristics and durability against weather. To directly address question 1, you design to minimize cement use by basing your walls after the traditional methods. The less cement for any clay based building type, the more structure and durability will effect architectural choices. Question 2 and 3 depend a lot on your cement/stabilization.

We’ve used watershed retaining below grade many time and simply protect it with appropriate drainage and vapor barriers as you would any concrete wall. A concrete toe is used at the base.

Feel free to reach out and best of luck,

Thanks Anthony!

This is very helpful.
Massey and I have been working together to find contractors, though we have been unsuccessful so far, but we will keep looking.

I will be sure to reach out if we need more info.


Good, engaged Earthen builders seem to be in short supply. You might converse with Ron Evans at De La Terra here in Texas. He’s from California originally and is active all over the country. His mail is txrammedearth@gmail.com


C. Michael Donoghue, PE
Maritech Engineering, Inc.
Austin, Texas, USA