Over the last several days, Chris and I have been working on the bond beam. The bond beam needs to be continuous (without joins) along the top of the tire walls. All the weight of the roof will be resting on the bond beam.

Traditionally, earthship bond beams are constructed by making an 8” high wall of mortar and pop cans on each side of the tires (with 8” of space in between for the concrete bond beam). The inside of every second tire will be scooped out (about a gallon’s worth) and the bond beam will fill these holes, securing the tires to the bond beam. The bond beam also serves to fix all the interior walls in place in readiness for the roof beams.

That’s the theory.

We have enough pop cans to do the bond beam in this manner but it would leave us without many to continue on with building planter walls and interior walls ( which use the same method as the side forms of the bond beam).

We have wood. In fact, we have a lot of off-grade machined house logs that we have decided to use. The logs are mostly off grade because of skip on the round face, some wane (missing wood) and too many pin holes to have made the premium house grade of logs we used to sell.

Here’s a photo of the first few pieces in place on the ousdie wall of the kids’ room.

 
After measuring, we took the log up to the truss saw (cuts angles).  Here’s Chris setting the angle…

 
First we check the angle on a test piece before cutting our log.