I'm finally getting around to finishing the flood cleanup from a broken pipe in Feb. (I've got a lot on my plate.) In Feb I removed the drywall in the basement and discovered that the painted foundation wall is bubbling and the
concrete is crumbling behind the bubbles. I have now removed the stud walls entirely with the intention of stripping the paint and plastering the concrete. There are also a couple cracks I'd like to keep an eye on so covering it with another stud wall isn't the solution. The surface of the concrete is quite rough and unpleasantly irregular so it will need some sort of coating to make it a nice place to live in (it was and will be the kids' bedroom). The exterior of the 95 year old foundation (obviously) has no waterproofing (other than our heavy clay soil) so the plaster must be breathable to allow the small amount of moisture that seeps through to evaporate into the room. The solution must also be dirt cheap. We're living in poverty for the foreseeable future and
free is the best price though I already bought and mixed up some hydrated lime in anticipation of needing a more durable surface to hold up to my kids. I've never worked with
cob or earthen plasters but I'm fairly experienced with traditional lath and plaster as I've done a bit of historically sensitive restoration work on the main floor.
The solution I'm hoping will be appropriate is to
cob over the walls using clay from the backyard. The
straw will hopefully take a bit of the edge off the winter cold coming through. Then finish with either a lime wash or lime plaster as deemed necessary for durability. Will the
cob stick to the concrete or will I need to screw up some metal lath? Most of the surface is pretty rough with 2-3" deep crevices scattered around the wall a few patches of remarkably smooth (but far from troweled smooth) surface. (Remember, this foundation was poured in 1919.)
I also have a couple interior stud walls that need a new skin on it. Since I hate drywall with a passion (and can only fit skinny strips of it into the basement, multiplying the most detestable part of the work), I'd like to use the cob and plaster for that too. Would
wood lath nailed to the studs be adequate to hold the cob or
should I improvise a wattle between the studs? I don't want to add much more thickness to those walls than what was there to begin with but a little extra
beef in the wall would hold heat better as it does get a bit of sun in the winter.
Does the cow manure really make that big a difference in durability? How fresh does it really have to be. That stuff is hard to find in the
city and will require some logistical planning to retrieve it from a friend's farm.
Am I deliriously naive or is this a reasonable plan? Other suggestions/improvements? Is there an equally cheap solution that would be faster? Winter is coming and I'd like the kids to be settled into their improved space before it gets too terribly cold (by Thanksgiving-ish at the latest).
Thanks in advance for the feedback. (c: