What is a Capstone?
A capstone is a project completed by all undergraduates before completing their degree at CSUMB. This is a showcase of the knowledge and skills gained in all undergraduate coursework.
Environmental Studies 472:
Projects in Environmental Education
For our capstone this semester, we will be working on increasing environmental literacy at Los Arboles Middle School (LAMS) in Marina, CA. We will specifically be working with Julie Haws' third-period environmental science class in the school's outdoor garden. We will be making improvements in the outdoor classroom that build on the projects done by the capstone class before ours. This semester, we will be working in four groups on three distinct projects:
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Ocean-Friendly Garden Practices
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Cob Bench Construction
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Owl Box Construction
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Owl Advocacy
This semester, I worked with three other students, Mika, Diana, and Yvette, on the cob bench project.
Getting Started: The Cob Process
Cob is a mixture of clay, sand, straw, and water used as a building material for homes, walls, and, in our case, benches. The clay soil is typically harvested from a local site by digging beneath the layer of topsoil into the deeper layer of clay-based soil above bedrock. The recommended proportions for an ideal cob mixture is approximately 1 part clay for every 3 parts sand. After the clay and sand are mixed, water is slowly added to soften the mixture enough to coat the straw. Straw is used in this case to provide more structure to the cob.
The first step to our cob process was to acquire clay. Typically, clay is source locally on or around the build site. We had the students dig in two areas in their outdoor classroom in search of clay soil. The soil was tested in glass jars through a particle separation activity and was found to have very little to no clay content. This process proved to be too time-consuming for the course schedule, so we chose as a group chose to source clay soil from the Olive Springs Quarry in Santa Cruz. After acquiring the soil, the LAMS students made sample cob bricks to test the consistency. The results were a success, so we moved on to stage two: the foundation process.
Making practice cob mixture with Los Arboles Middle School students
A student digging for clay soil in the outdoor classroom
Foundation Building
The foundation of the cob bench serves as a barrier to protect the cob from washing away in the rain or being dug up by animals. Our foundation was made of recycled pieces of cement and mortar mix. We collected the cement from around the outdoor classroom, a local recycling center, and my parents' backyard (thanks mom and dad!). We started by digging a four-inch deep outline of the bench and laying the cement pieces inside. This additional layer of foundation underground provides the bench with extra stability. We then build the layers up to about a foot off of the ground for the final foundation. Most cob experts recommend a two-foot foundation, but, since our bench was to be relatively small and this area sees very little rain, we decided that a one-foot foundation would be sufficient.
LAMS students mixing mortar
Piecing together all of the recycled concrete
The finished foundation
Recommendations
Due to the global pandemic of COVID-19, we were forced to stop our capstone project after the completion of the foundation. If we were to have continued with this project, our next steps would have been to mix the cob and actually construct a bench for seating. Cob can take up to a year to fully dry, and it must be coated with a protective layer after the drying process has completed. I would recommend that the LAMS students start mixing cob when they return to school to give the bench as much time to dry as possible.