Cob: RE: cleaning earth plaster

[Patrick Newberry]

Yes you are right, Lime would be better, but my point is sort of to say
sometimes in our world we take a good idea
and beat it to death. So while it is true that vapor barriers have
caused moister problems in cob walls. That does not mean that 
some of these products can have more limited functions in the building
of a house, even a cob house. Most of my house was build
from stuff I found, was given or dumpster dove. 

Thus it  is a whole different story then saying you can never under ANY
situation use a latex paint on a cob wall vs saying
There are ways that latex paint can be used and not cause moister
barrier problems. In my example I might just paint 
the area right behind the sink, or in the other example a particular
high area of hand print potential might be painted. If the wall is 
still allowed to breath as in my example the back side would have lime
only and the area above the sink side would be lime only.

In the test area I tried it had even direct water splashing on the wall
and it has held up for three years now. 

another example which I plan on trying is to paint a "trim" like strip
around my cob windows. My walls will be white with a lime / white sand
mix. 
and since I used old windows embedded in cob with arches rather than
headers I have no wood. I plan on painting a bright colored, maybe four
inch wide
strips around the arches to give some color to the wall and to
high-light the windows. Again because it will be very localized, it
really won't be much of a vapor 
barrier. 


But then again, I have always lived on the bleeding edge of earth
building technology. I've had failures before, like collapsed domes and
arches, testing the extremes. 
One question is to ask yourself, if this fails what will be the result.
A reasonable small area of laxtex paint on a cob wall failing does not
stike much fear in my heart. 

Pat 
http://www.gypsyfarm.com

-----Original Message-----
From: Darel Henman [mailto:henman at it.to-be.co.jp]
Sent: Thursday, November 29, 2001 12:30 AM
To: Patrick Newberry
Cc: coblist at deatech.com
Subject: Re: Cob: RE: cleaning earth plaster


Patrick,
  I think, but, am no expert that a lime paint or lime wash would be
better than latex or other vapor barrier causing paints.  I guess you
are suggesting just covering a given area, such as the kitchen only. 
I've seen data that if the walls can breath they will regulate the
humdity inside better and prevent molds from forming.

Darel

Patrick Newberry wrote:
> 
> my brother in law and I have both  have painted sections of cob with
> regular laytex paint.
> He did a much larger area than me, but both of us has resonable
results.
> 
> I don't have a lot of data yet on the results but on the patch that I
> painted outside, somewhat exposed to weather,
> it has  lasted so far for about 3 years and the wall around it has
been
> errording, but the patch is  still doing fine.
> 
> I'm going to experiment with this in the kitchen are near the sink and
> stove. I don't think that enough area will
> be covered as to cause moisture barrier problems. I should have some
> results by spring to let you know.
>