Day 3 started with our usual 7AM breakfast fuel-up before heading to the build site. We finished laying the foundation bags and started stacking up the first layer of earthbags for our dome. We also leveled out the exterior area for the buttresses that would support the structure.
After a nourishing lunch, Mariana taught us how to assess soil quality and find the optimal ratio of ingredients for our earth mixture. We learned different methods for testing the strength of experimental ratios if you don’t have access to a lab.
The basic process involves tamping down various mixtures of soil, cement or lime, and water, letting them dry for 3 or 7 days depending on the binder, then submerging them in water to see if they withstand dissolving. The mixture that stays most intact is the winning combination for site conditions.
Here we were using 10 buckets of soil to 1 bucket of cement, but Mariana’s test samples showed room for improvement. She adjusted to a 9:1 ratio which performed better. We put this refined mix into practice, completing another layer of bags.
With our team off dinner duty, I enjoyed a long hot shower and chatting with our diverse participants from around the world. We played cards around the fire before heading to our tents for lights out at 9PM. The composting toilet is definitely an adjustment but aligns perfectly with the eco-conscious ethos here!
I’m consistently impressed by Mariana’s meticulous testing and tweaking to optimize our materials. I can’t wait to see our carefully crafted soil mixture harden into a stunning, long-lasting dome through natural processes!
