More plaster & more bales

Last week, we stacked the first fifty feet of straw bale wall and started the first coat of plaster. Dad and I finished the first coat of plaster on the west side by the end of the week. Today, Jon and I plastered the north side.

Our plaster recipe is five gallons of clay dirt which has been screened through 1/2” and then 1/4” hardware cloth, five gallons of sand, two gallons of chopped straw, one quart of homemade wheat paste, and about 3 gallons of water. We mix it in my electric concrete mixer. It mixes into the consistency of a chocolate mousse.

The plaster is spread on the bales by hand. We are really working it into the bales, making sure it is well keyed in. The goal at this point is a thin covering of plaster that will adhere well while revealing the topography of the bales. It takes a bit of time to work it in this way, but I want to be sure it is a good base for the next coat, one that will not come off.

We finished the first coat on the north wall by lunch time. So, after lunch we started stacking some more bales. Our approach is to build the walls in sections. Most of the walls will have to be protected from the elements until they are well plastered. So, I don’t want them all erected at once.

Our second bale wall section begins at the door from the kitchen to the summer kitchen and ends at the front door. I debated about whether or not to dip the bales in clay slip this time. It adds an additional couple of steps and slows down the stacking of the bales. We found little advantage to our dipping efforts the last time.

The idea with dipping is to have a coating of clay on the bales for the discovery coat to adhere to. We didn’t end up with that much clay on the bales, at least not enough to help with the plastering except in one or two spots. Also, trimming the face of the bales with a weedeater string trimmer makes a nicer surface for plastering than not trimming then, but it also knocks off a fair bit of the clay from the slip.

So, I decided that we will just continue working the first coat of plaster well into the bales and not worry about dipping them in clay slip. We’ll spend the extra time required in plastering rather than spend extra time in mixing clay slip and dipping bales before stacking them.

Stacking the bales around the kitchen and to the front door meant that we built a section of wall against the timber frame in one area. There is a window opening framed in this section for a 1 foot tall by 4 feet wide window on the wall behind the wood stove. This gave me an opportunity to experience hanging bales above a window. My idea was to round the bottom inside edge of the bale and then hang it above the window with chicken wire (poultry netting). The concept worked, as you can see in the photo to the right. There are still a couple bales to be added  to the wall on either side. I’ll have several more windows above which to hang bales as we progress.

I’ll pin the bales tomorrow, trim their faces, and fill voids, if all goes well. I’d like to start plastering the outside of this wall section on Wednesday.