This rear corner view shows more detail of the fully plastered composting chambers, door thresholds and center divider. Since the ground under the chambers is mostly solid lava and was cleared of roots and other organic matter, the bottom rear corner was simply plastered right down to the ground.
Here the West Wing and portions of the center divider wall are shown fully plastered. The vent pipe connector for this chamber can be clearly seen - it was put in place through a hole cut in the mesh and plastered into the wall in the same way as the vent for the East Wing.
Presidential candidate Erik Thompson is standing in the East Wing, leaning on the wooden joists that will support the floor of the Oval Office. These joists are made of 2 x 4 lumber. The front support is a T-beam shape, with a 2 x 4 laid on its side as the top of the T. There will be a joint in the flooring material centered on top of this support. The T-beam shape provides an adequately wide surface for mating and securely attaching the edges of the two separate pieces of flooring.
Attachment of the east end of the rear floor joist. Standard galvanized hangers and brackets were modified by cutting and/or bending to match the necessary angles between floor supports and walls. Galvanized 1/4" carriage bolts, washers and nuts were used to attach the brackets to the ferrocement. Coarse-thread self-tapping screws were used to secure the wood in the brackets.
The floor is plywood and is cut to match the shape of the top of the chambers, with a slight overhang. It is secured to the wooden joists using coarse-thread deck screws. Industrial construction adhesive (applied using a caulking gun and/or gloved finger) is used to secure the plywood to the top edge of the ferrocement wall and to seal small gaps due to the roughness of the top of the wall. To further secure the rear edge of the floor, wooden blocks were bolted to the inside rear of each chamber, flush with the top edge of the wall. The floor was then screwed to these blocks from above.