I have included lots of pictures here to fill in some of the gaps from previous posts. Starting from the bottom, we can see the Roxul toe up insulation that connects the bale walls to the subslab insulation.
Notice the wood edge to the slab which was the form for the slab and will be a nailer for baseboard. It will also connection the clay plaster air barrier to the sub slab air/vapor barrier which runs under the roxul to the exterior drainage plane.
Now going to the top, you can see the framing over the door that will be the same as over the windows. Simple 2×2 framing attached to the floor joist above and in plane with the bales. It is important to have down all your finish details around window and door frames. In this design we plan to have wood sills and headers and wrapping the plaster right to the window frames on the sides. We are using Alpen fiberglass 525 series windows with a slim wood caseing that will act as a plaster stop. We are making sure that the bales cover the stud frame to minimize thermal breaks. This detail will be shown in future posts.
Here are process photos showing on the left, screwing the top bales in place to allow sliding bales into the gap.
On the left, you can see bales coming up from the first floor. Notice the air barrier connection between floors that create continuity between primary plaster air barrier from first to second floor.
Here is the finished bale wall with strings cut, strapping up, and bales fluffed together. We have also attached a nailer on the ceiling joists that is in plane with the rough plaster to attach moulding to and create a plaster stop. The finish plaster will end at the moulding. Strapping is pulled tight to flush out with bale plane.
We have found that there still may be some loose straw stuffing needed but nothing to the scale of your typical straw stuffing process when you leave the strings on.
Probably the biggest issue is dealing with securing bales around windows and doors. We found that bales are definitely expanding when strings are cut. Some of the considerations we are working on to deal with this is leaving strings on the bales around the windows. We are typically stacking bales vertically around windows and doors. We are also securing strapping around windows and doors diagonally to studs in line as much as possible with outward expansion of bales.
Stay tuned for more pictures of finished walls and securing details around windows.