Pinning the bale wall

This morning the boys and I cut down several large saplings, mostly Mimosa which grows like a weed around here. We trimmed off any small branches and brought them to the house. Their purpose was to help strengthen the straw bale walls.

If you’ve read or watched anything about straw bale building, you may be aware that one of the accepted practices is to drive rebar through the bales in order to tie them together. In some places the code for a straw bale home requires rebar. After stacking the bales yesterday, it was clear that there is a good reason for some means of tying the bales together and increasing their rigidity.

I didn’t want to use rebar, and it isn’t the only way to achieve the desired end. I’ve read about another method and opted to use it. It involves pinning the bales with external pins, Mimosa sprouts in my case. Since I already have a frame work of 2x4s on the outside of the bales, I only need the sprouts/saplings on the inside of the walls.

To pin the walls this way, I put some fence staples into the edge of a 2x4 on the outside of the wall. Using my bale needle, I then pushed a loop of baling twine through to the inside of the wall leaving the two tail ends on the outside near the staple. I pushed these pieces through in four places on the 2x4 from top to bottom.

I inserted one of the Mimosa sprouts which had been cut to length to extend from the top to the bottom of the bale wall through the loops. Then, from the outside of the wall, I pulled the loops tight and tied the strings to the staples. My tying process involved cinching the strings tight enough to embed the sprouts into the face of the bales.

Tying the Mimosa sprouts tightly to the external framework really stiffened the wall. It imparts a lot of rigidity to the wall by connecting the bales together and holding them immobile against the outside of the wall. I was quite pleased. With Ramiah’s help, I was able to pin the walls in the sewing room/study.

Once we had pinned this section, the boys and I stuffed straw into the voids we could find between bales, both on the inside and outside. For the outside few inches, we used straw that had been dipped in clay slip. We used dry straw inside the middle of the wall since it would have a hard time drying there if it was wetted with the clay slip.

We’ll continue pinning bales and filling voids tomorrow. I was a bit too optimistic about plastering tomorrow, I think.

Here are some photos of the plastic sheeting I put up to protect the walls. I nailed a 24 foot long 2x8 at the bottom of each piece. This should keep the sheeting from blowing away if the wind picks up. It also allows it to be pulled back, making room to work on the wall under the plastic, and to be held in close to the house when it’s not necessary to work under it.