This is a diary entry from the May straw bale workshop Day 5. This day started and ended in mud. The good news is that it was mud we were making and using to plaster our beautiful straw bale structure. We are working with lime plaster and as a result, we had a lot of dust masks around.
The plastering process is long and tiring and is one step of the building process that I often suggest people hire out to professionals. After all, the plaster is such a prominent part of the house and is what people see when they come and visit you. A major mistake there will be a real bummer in the end.
The mix we plastered with is a combination of Natural Hydraulic Lime, sand, water and chopped straw. The straw acts as a binder for the mud and tightens up the whole thing. A lot of care must be given to the ratios of the ingredients to ensure a consistent and strong plaster. At the end of the day, the entire inside of the structure was completed and scratched in preparation for the second coat or brown coat. The drying time for the plaster will not allow us to plaster directly onto the same mud that we have applied today, so we will move to the exterior of the structure and plaster that tomorrow.
Some areas are more difficult than others to plaster so patience is a needed ingredient to the mix, especially when folks are just learning. Perhaps the hardest places to plaster are the lids of the window wells and tight corners. The need for really tightly packed stuffed straw in the curves of the windows and doors becomes really obvious when plastering. If the loose straw is not packed tight enough, the mud simply will not stay put on the lids, something that will test anyone’s patience the tenth time it falls off!