[Cob] Repairing eroded limewash over earthern plaster

[Bernhard Masterson]

Hello Hugh,

I would recommend replastering with earth first. Sounds like the erosion is uneven enough that if you just went for a limeplaster repair you would risk cracking.  Begin by scratching through the limewash to give a good mechanical connection for the leveling coat.  Once done you could reapply the limewash or a lime plaster.  If you choose to use a lime plaster as a top coat I would put something like 10% lime in the earthen plaster you are using for fill.  That will help the top lime coat bond. It sounds like there may be a roof overhang deficiency or do you regularly get driving rain and hail?  or could you provide additional protection to the wall from a change in eves?

- Bernhard 



Get under a sustainable lifestyle umbrella, the carbon is going to hit the fan.

____________________________________http://bernhardmasterson.com

Natural building instruction and consultation

Message: 1
Date: Mon, 13 Feb 2012 13:24:00 +1100
From: Hugh Withycombe <hughali at webone.com.au>
To: coblist at deatech.com
Subject: [Cob] Repairing eroded limewash over earthern plaster
Message-ID: <2736B007-B810-4E79-A64D-D968461F2943 at webone.com.au>
Content-Type: text/plain; charset=us-ascii
 
I have some eroded patches where hail damage and heavy rain has broken through limewash on an earth plastered wall.  In some places the wash out goes about 2cm or just less than an inch deep.  In other it is just the limewash and the finishing coat of plaster that has been removed.  I am looking for some advice as to whether it is better to remove all the limewash from the affected areas, then replaster and put a top coat of limewash.  Or can I just fill the area with a thicker lime plaster and skip the earthern fill?
Thanks in advance, Hugh Withycombe Canberra Australia