siu-yu man wrote:Bill, curious, in retrospect, how would you do this differently? what did not work?
In retrospect, I would not use any OPC based products with any kind of lime plaster. They behave too differently and this resulted in cracks appearing at the seams between the sheets of cement board.
Gypsum and lime get along famously. The predominant plastering system in homes 100 to 150 years old is lime render, gypsum plaster and then colored lime top coat, so this is what I mostly use in my restoration work. A modern interpretation of that system is what you see in the first photo. I installed drywall on the stud wall, then plastered that with a greenguard certified all purpose joint compound then top coated with type s hydrated lime aged 1 month mixed with brick slurry from a brick saw, application by 6 inch brush and immediately trowel burnished, dried leather hard and then
local goat
soap dissolved into warm
water is painted on with the same 6" natural bristle paint brush and burnished with a cut piece of local limestone.
I am a restoration contractor, so I always have a bottom line. I experiment with combining ancestral techniques with modern industrial products on my own home in order to work out the bugs before doing any
job professionally. This really isn't natural building, so I have been reluctant to share some of my techniques here on Permies, but I have decided that less than perfect is sometimes good
enough.