Cob: RE: breathing cob walls

[W]

good question.

I helped to build a cob hom in BC and I wondered the same thing (though for some reason not out loud...) as I built cob walls to be tiled in the form of a shower...

anyone else?
---
PeaceLoveLightLifeBeautyTruth
W.

On Mon, 15 May 2000 12:37:42   Kelly, Sean wrote:
>In the same vein, how does applying tile to a cob wall work?  I mean, say I
>wanted to put up tiles in a bathing area, wouldn't putting up glazed tiles
>with mortar seal the wall, and wouldn't that be bad?  Or could you just
>embed the tiles in the cob?  I also had a friend who was thinking of using
>tile to mosaic the outside of a cob building...  Would this cause breathing
>problems?
>
>-----Original Message-----
>From: Bob [mailto:owl at steadi.org]
>Sent: Friday, May 12, 2000 11:57 PM
>To: coblist at deatech.com
>Subject: Cob: breathing cob walls
>
>
>I'm glad someone brought up the need for cob walls to breathe.  In New
>Mexico the restorers had the bright idea of coating the outside of a very
>old adobe church with mortar to protect it from the weather etc.  It almost
>destroyed it, however.  Moisture that is in most all air entered the wall
>from the inside and got trapped just under the mortar. Over the years it
>softened the clay in the raw (unfired)  bricks.  Watertight sealants will
>gradually soften the clay under them.  It may not show in a year but it will
>over time. 
> This church was in a quite dry climate near Santa Fe, New Mexico.  If you
>would like more details I will look up the recent Smithsonian article and
>put the page and issue on this net.
> 
>IT IS DANGEROUS TO TRY TO SEAL AN ADOBE OR COB WALL.  THEY NEED TO BREATHE.
>
>Potassium silicate, I believe is a sealants that can cause this gradual
>deterioration of unfired clay walls.    You may be undermining your
>building.  Just what potassium silicate would do to garden walls is another
>question.  Perhaps they would make the wall last longer than an unprotected
>rain drenched wall.  Much better are the ideas of putting a roof on the wall
>with an overhang and putting stones in it that stick out.  Even terracotta
>(cooked earth) tiles that are not glazed, just low fired, would be good
>protection even though they are a little porous.  Most of the rain would run
>off.  If the wall breathed the little moisture that went through into the
>wall would likely work its way to the sides and evaporate.
>
>What is important to remember is that even inanimate things are dynamic,
>changing slowly or fast depending on the climate.  In the Egyptian desert
>they can last for thousands of years but there are few places  that dry in
>the world.  Even the ancient hieroglyphics thousands of years old, when
>inclosed and viewed by too many  tourists can be destroyed by the moisture
>evaporating from their bodies.  So we have to bend with the weather and the
>impacts of changing climates and recognize that every move we make impacts
>the world of future generations.  Acid rain, thanks to our  blind use of
>technology, is decaying even stone monuments that lasted thousands of years.
>The automobiles in Athens are destroying the ancient Athenian buildings, for
>example.
>
>Americans look for quick fixes.  When they are efforts to short cut natural
>processes they always backfire.  Cob is great because it is mostly a product
>of nature and when properly used and cared for can last for ages.  Tune into
>it and it will give you a singing house.  Try to defeat the natural process
>and they will let you down, or let the roof down on your heads.
>
>Bob 
>
>
>
>
>


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