We decided to use pressure treated wood for the soul or bottom plate. We could not find local foundation grade redwood that will protect against the concrete cores of the Faswall blocks that they are sitting on the way pressure treated wood does. Another option is using a rubber sheet that sits under the soul plate and will protect the wood from the moister that concrete pulls into the wood.
To match the roof kit that we purchased from Smiling Woods Yurts to our foundation walls it was best to drill into the foundation and epoxy the anchor bolts after foundation was poured. The first step was drawing a circle from the center pole to the outside of where the studs will be. Then we used the top plates as a pattern to trace and cut out the bottom plates. All-thread was cut 8" long which provided over 5 1/2" of embedment in the concrete. Next we drilled and epoxied the bottom plates. We used compressed air and a brush to clean out the holes before gluing them in place. The glue didn't set fast so we had time to hit between 16-19 bolts with one tube of 22oz epoxy. The bolts then were pulled up and down to spread the glue and we turned them 1/4 turn to lock the glue in place.
The anchor bolts are hot dipped galvanized which will protect them from the pressure treated wood. We will be painting the tops of the bolts, nuts, and washers to protect them from the alkalinity of the lime in the hempcrete walls while it cures for the first few weeks..