This week I managed to find some time to get my first coat of clay plaster on the straw bale walls. I wasn’t sure what to expect, but I was looking forward to not having to wear gloves and safety goggles like I had to with the lime render.
I soaked the clay I had for 24 hours and hand mixed it into the sand per bucket. For my ratio of sand to clay, I went for a high clay content and didn’t worry too much about accuracy or consistency between mixes, as this is the first coat and the primary aim is to get it keyed into the straw well, rather than smooth and crack free. In fact, cracks will help the second course stick well to the first.
My initial reaction is that clay is very fun to work with! It’s messy and sticky, but mixing by hand is nice and relaxing and easy. It’s also very fast, at least for the rough coat I threw on. I managed to get the inside of the studio done in two days, where as the lime render took five days, with help.
I’m letting the render dry over the weekend, and as it’s inside, this is going to be a slower process than the lime render, but once it’s done I’ll get some test patches completed and start thinking about my specific mix for the thicker coats.
By the way, I got my information on clay plastering from here – http://buildnaturally.blogspot.ca/2011/07/clay-plastering-strawbales-first-coat.html?spref=fb