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GSBN: Digest for 10/12/07



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-> RE: GSBN Lime plaster problems
     by "Andy Horn" andy@...
-> Re: GSBN: Lime plaster problems
     by "=?UTF-8?B?QW5kcsOpIGRlIEJvdXRlcg==?=" forum@...
-> Tom Rijven is is finaly available in Print (in French and English)
     by "Andre_de_Bouter" forum@...
-> Re: GSBN: Earth plasters
     by "Andre_de_Bouter" forum@...
-> Re: GSBN:Re: Lime plaster problems
     by Athena & Bill Steen absteen@...
-> Re: GSBN: Japanese plasters
     by Athena & Bill Steen absteen@...
-> Re: GSBN: Earth plasters
     by Athena & Bill Steen absteen@...
-> Re: GSBN:Re: Lime plaster problems
     by MattsMyhrman@...
-> Re: Pulped Paper as a Fiber Source
     by MattsMyhrman@...
-> Re: GSBN:Re: Pulped Paper as a Fiber Source
     by Tom Hahn tomhahn@...
-> Re: GSBN: Earth plasters
     by Graeme North ecodesign@...


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Date: 12 Oct 2007 03:22:45 -0500
From: "Andy Horn" andy@...
Subject: RE: GSBN Lime plaster problems


Hi Derek and all

Afraid I have been having problems with my email's so have been unable to
respond to all your inputs=85.which are hugely appreciated.

Just to explain Derek, yes we did the plastering in late April early
May...i.e. autumn just before winter kicks in....the problems only seemed to
become apparent further down the line. 

The site is in Kokstad, which is well inland quite near the Lesotho and
Drakensburg highlands. The winters are generally very dry with sunny days
average daily temperature about 16 - 18 degrees, with cold nights (no cloud
cover) getting down to just below freezing in the early morning....hence it
is usual to experience frost in the early morning. While there are lovely
warm days, winds are cold and during the heavy cold fronts they normally get
snow on the neighbouring mount Curry which is only a few km away and
sometimes even on the ground in Kokstad. Further to add there is much snow a
150km to the north in the Drakensburg mountain range that usually hangs
around on the mountain tops for at least half of winter and especially after
the major cold fronts, which bring chilly winds down from those mountains.

We will only be re-appling the plaster when I get to the bottom of this all,
which should be early summer again.

Just to also mention that this site is about 1000 km from my home in Cape
Town, so my visits are quite irregular and usually quite pressured.
In retrospect, when the strong winds and cold weather conditions started I
should have rather packed up and persuaded my client to wait until after
winter.

Thanks
Andy


- -----Original Message-----
From: Derek Roff [<a  target="_blank" href="mailto:derek@unm.edu";>mailto:derek@...] 
Sent: 11 October 2007 03:46 PM
To: Andy Horn
Subject: RE: GSBN: Lime plaster problems

Thanks for your response, Andy.  Did you also post this information to 
the GSBN list?  I suspect others would be interested.  Your questions 
stimulated a lot of interesting discussion.

Derek

- --On Wednesday, October 10, 2007 9:20 PM +0000 Andy Horn 
andy@... wrote:

> Hi Derek
>
> Afraid I have been having problems with my email's so have been
> unable to respond to all your inputs?.which are hugely appreciated.
>
> Just to explain Derek, yes we did the plastering in late April early
> May...i.e. autumn just before winter kicks in....the problems only
> seemed to become apparent further down the line.
>
> The site is in Kokstad, which is well inland quite near the Lesotho
> and Drakensburg highlands. The winters are generally very dry with
> sunny days average daily temperature about 16 - 18 degrees, with cold
> nights (no cloud cover) getting down to just below freezing in the
> early morning....hence it is usual to experience frost in the early
> morning. While there are lovely warm days, winds are cold and during
> the heavy cold fronts they normally get snow on the neighbouring
> mount Curry which is only a few km away and sometimes even on the
> ground in Kokstad. Further to add there is much snow a 150km to the
> north in the Drakensburg mountain range that usually hangs around on
> the mountain tops for at least half of winter and especially after
> the major cold fronts, which bring chilly winds down from those
> mountains.
>
> We will only be re-appling the plaster when I get to the bottom of
> this all, which should be early summer again.
>
> Just to also mention that this site is about 1000 km from my home in
> Cape Town, so my visits are quite irregular and usually quite
> pressured. In retrospect, when the strong winds and cold weather
> conditions started I should have rather packed up and persuaded my
> client to wait until after winter.
>
> Thanks
> Andy
>
> ECO DESIGN
> Architects &amp; Consultants
> A. R. HORN B.A.S. (UCT), B.Arch (UCT), Pr.Arch (SACAP),       MIA, CIA
> Telephone: 021 462 1614, Fax: 021 461 3198
> Cel: 082 67 62110
> 4th Flr, The Armoury
> 160 Sir Lowry Rd
> CAPE TOWN
> 7925
> web site:  HYPERLINK www.ecodesignarchitects.co.za
> www.ecodesignarchitects.co.za
> email: andy@...
>
>
> -----Original Message-----
> From: Derek Roff [<a  target="_blank" href="mailto:derek@unm.edu";>mailto:derek@...]
> Sent: 27 September 2007 02:05 PM
> To: GSBN; Andy Horn
> Subject: Re: GSBN: Lime plaster problems
>
> --On Wednesday, September 26, 2007 6:37 PM +0000 Andy Horn
> andy@... wrote:
>
>> On the first morning after applying the plaster the weather
>> turned at night and brought frost...2 months ahead of when it is
>> normally expected! There were sheets of ice in the water buckets
>> that morning!
>
> I am curious about the comment that this freeze was 2 months _ahead_
> of the expectation.  I'm thinking that, as of the date of Andy's
> message in late September, South Africa is moving into Spring and
> looking forward to the warmer temperatures of summer.  Perhaps the
> plaster was applied in April or May?  Andy, can you clarify what
> temperatures were "normal" when the plaster was applied, what the
> normal freezing season is like (and when), and what weather you
> expect from now into the next few months, when you will be
> re-applying the plaster?
>
> A few more questions come to mind from your description of the
> problem.  There is a great deal of variation between different lime
> sources/stocks.  Is there an alternative to hydrated lime that you
> used?  Is this brand of lime generally reliable when used in the
> manner that you applied it?  Is it possible that the bags of lime
> which you used had been stored improperly or were very old?  Does
> soaking this specific lime for days or weeks prior to application
> have a significant positive effect on this lime's working properties?
> (While hydrated lime is slaked at the factory, some members of the SB
> lists report that their hydrated limes get better with soaking).  Did
> anyone do test samples of this lime, using your mix and application
> techniques?
>
> You mention adding a small amount of adobe soil to the render mix.
> Soils vary tremendously, and some of them are not happy companions
> with lime.  Some soils and mix ratios can decrease the strength
> and/or adhesion of the render.  Is there a compelling reason to
> include the soil in your mix?  If so, testing various mixes and
> ratios could be enlightening.  Please tell us more about how much
> adobe soil was added, and if possible, what the pH of the soil is.
>
> Derek
>
>
> Derek Roff
> Language Learning Center
> Ortega Hall 129, MSC03-2100
> University of New Mexico
> Albuquerque, NM 87131-0001
> 505/277-7368, fax 505/277-3885
> Internet: derek@...
>
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>



Derek Roff
Language Learning Center
Ortega Hall 129, MSC03-2100
University of New Mexico
Albuquerque, NM 87131-0001
505/277-7368, fax 505/277-3885
Internet: derek@...


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Date: 12 Oct 2007 04:06:48 -0500
From: "=?UTF-8?B?QW5kcsOpIGRlIEJvdXRlcg==?=" forum@...
Subject: Re: GSBN: Lime plaster problems

Hello, it has been very interesting catching up on the lime plaster on 
earth thread. Thanks everyone.

A French practice to increase adhesion of lime plaster on earthen 
plaster is to apply wet the earth plaster/wall with what we call 'strong 
water'. This is the water that floats above the quicklime (or a mix of 
20 water for 1 lime).

By the way, all wattle and daub multi story houses I see in France have 
been lime plastered quite some time ago, probably by masons who knew 
their lime and their soil (all three local!). Though I hear what Bill's 
Japanese plaster master says about lime on earth. It does seem to stick 
for quite a while when done correctly.

I recently saw a lime wash over earth (not very common in France as far 
as I can tell) and was impressed how it greatly increased the strength 
of the plaster when I scratched it with a nail of my thumb . The same 
plaster without lime wash was easily destroyed with the same amount of 
pressure. This lead me to believe the mason who told me that the lime 
goes in quite deeply into the earth and is not only a coat on the 
surface. I quite liked the reply of that same mason when asked: "How 
long before a lime wash needs to be redone" His reply (with a slight 
grin) "that depends on the amount of weathering you can accept".

> ah yes, on to Roman cement...   this is going to get good... come on you
experts.
>   
Limes vary in clay content (here she is again ;-). The more clay, the 
more hydraulic the lime is (meaning that the reaction is fast and set 
off by the water and less by the air). The old masons (and the young 
ones too) would add different types of additives. Not to get a better 
lime, but to adjust their (local) lime to the the way and place 
(plaster/foundation etc.) it was used. Hence, when it seems that some 
type of soils work better with lime than others, the same might be said 
for different type of limes. It is only since quite recently that we 
'import' lime from other regions. Maybe local limes work (often) with 
local soil? (this is just an idea!)

The French book I'm reading at the moment goes on to say that only 
washed sand should be used because clay particles can be a disaster. But 
the oldies also mixed their lime with soil to obtain plaster. One sample 
of lime and soil I tested worked just fine with 1 lime for 3 (clay rich) 
soil but the same soil with only 10% lime turns to dust when one touches 
it. I now show this sample during workshops to make the participants 
realize that all this mixing of ingredients really is alchemy for 
beginners as I have no clue as to what type of clay(s?) are in my soil 
and only have a vague notion of how hydraulic a bag of lime is supposed 
to be. It' is more or less like, huh,... what would happen if I push 
this red button here... There's only one way to find out unless someone 
has done it before you have (and is still there to tell you).

I used to find all this lime in/on earth way to complicated for me and 
steered away from it. But the before mentioned mason showed me some very 
nice samples that have roused my interest.
It must be a bit like women : I have no idea how they work, but that 
don't mean they don't.

Andr=C3=A9 Test Test Test de Bouter

>
>  
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>  
>
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>
>
>
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>
>
>
>
> -----Original Message-----
>
> From: Andy Horn 
>
> To: 'GSBN' 
>
> Sent: Wed, Oct 10 4:40 PM
>
> Subject: GSBN: Lime plaster problems
>
>
>
>
>
> Interestingly the locals in Kokstad who build with adobe ...but don't add 
sand to help with cracking will search to find a much rarer creamy coloured 
clay that can be found in the area to do their plaster coat with....and will 
then typically apply a lime wash to finish with. However they have not  learnt
to add sand so the walls are usually quite crazed with  cracks.....Sometimes
they also add cow dung which helps somewhat with the  cracking.    Not sure if
we can get any marble dust in that area,,,,but as I understand  it you would
want that in the earth plaster to get the bond to the lime  coat......   
Interestingly I hear from an archaeologist/conservator friend of mine that 
the Romans often used to add marble dust to their lime plaster. The other 
thing the Romans did was add fine fired brick or tile dust/powder to their 
mixes.....not sure what that was for or if it was simply instead of or when 
they ran short of sand???     Andy Horn    -----Original Message-----  From:
GSBN [<a  target="_blank" href="mailto:GSBN@...";>mailto:GSBN@...] On Behalf Of Athena &amp; Bill  Steen 
Sent: 08 October 2007 02:02 PM  To: GSBN  Subject: Re: GSBN:Re: Lime plaster
problems    Franko,  I think a major plus in your area is the calcium
component in the    caliche soils.  So therefore we have a chemical connection
going on    beside the mechanical.  And that is what is basically lacking with
   most soils.  One way to increase the possibility of a better chemical   
bond is to use marble aggregate instead of quartz sand.    B...  On Oct 7,
2007, at 2:50 PM, thangmaker@...:    > Thank you, Bill.  I have had
good results and no problems to date    > putting lime over earthen plaster
made with our native caliche    > clay.  We have done what Bill  >  >  >
suggests:  scratching the surface well and letting the earthen    > plaster
dry completely.  For those unfamiliar with caliche it    > occurs in the same
soil as limestone.  >  >  > It is the same basic material as lime (calcium
carbonate) but less    > dense and not well bonded to itself...flakey if you
will.      > Occasionally clay is found with this  >  >  > material and is the
best clay I have seen in terms of PI index (low    > expansion and
contraction).   This is the clay I wanted to use for    > the fire test last
year in San Antonio but as Matts pointed out it    > would not perform well in
a hot fire.   I am guessing the material    > is similar enough to lime
plaster that it both bonds well to it and    > their rate of movment and
reaction to moisture is similar.  >  >  >  >  >  > Cheers  >  >  > Frank Meyer
 >  >  > PS we are hosting a Natural Building Colloquim later this month    >
www.naturalbuildingtexas.org and have a great caliche clay pit on    > site. 
>  >  > -----Original Message-----  >  > From: Athena &amp; Bill Steen  >  > To:
GSBN  >  > Sent: Sun, Oct 7 12:11 PM  >  > Subject: Re: GSBN:Re: Lime plaster
problems  >  >  >  >  >  > I'll plead busy as well and before I made any
comments I wanted to    > make sure they would be somewhat thorough. There are
a few things    > that have become evident to me over the years when it comes
to lime    > over clay plaster. In mho I would have to say that results are   
> unpredictable and undependable. I'm not saying it can't or doesn't    >
work, but rather that outcomes vary widely. David Bainbridge    > mentioned in
his earlier post the Getty people in Los Angeles as a    > resource. I've made
it a point to talk with them every few years    > about lime plaster and in
particular their work with prickly pear    > cactus gel. Anyhow in one of the
last conversations we had they    > told me that there was a growing sentiment
amidst the conservation    > community that the use of lime plaster over earth
surfaces was not    > such a good idea. They mentioned that although lime had
better    > permeability than cement and allowed the earth to dry better when 
  > wet, it was still too different from an earthen substrate for it to    >
work dependably.  >  >  >  > My experience basically says the same thing. For
me the whole issue    > comes down to what type of earth plaster is
underneath. Apparently    > some are much better than others and just what all
the variables    > are I can't say. I think it will take some time to get a
better    > grasp on it. Clearly I would suggest that if the substrate has a  
 > lot of clay there is a likely possibility that if water is absorbed    >
through the lime plaster and passed on to the earth substrate then    >
obviously the clay will expand and have a tendency to push the lime    >
plaster away therefore causing the two to separate. If the earth    > plaster
is weak then the connection will break down over time. So    > in short I
guess what I'm saying is that the earth plaster has to    > be of a really
good quality for any chance of success. It needs to    > be strong and not
have an overly high content of expansive clay.    > Another very important
piece is that the earthen plaster substrate    > must be thoroughly dry as
earth plasters shrink when drying. If    > that process is not complete the
earth will pull away from the lime    > plaster and leave it hanging in the
air. And as others have pointed    > out the surface needs to be extremely
well keyed for the lime to    > adhere. I don't think you can under-do that
aspect. Additional    > measures like that of placing sharp jagged stones in
the plaster    > would also help such as the practice of "rahuela" used in
Mexico    > where stones are placed in the mortar joint between adobes.  >  > 
>  > I think it was David that also mentioned the Japanesete We have    >
worked closely with a pair of Japanese plasterers over recent years    > and
it is important to note that the Japanese approach relies    > heavily on use
of a glue when mixing what they call "Shikkui."    > Traditionally rice flour
was used but was replaced with seaweed gel    > during a time of food
shortages. In general I would say that their    > plastering practices are far
more meticulous than anything I've    > seen in this part of the world and in
the words of the best    > plasterer from there that I can think of, "there is
great    > difficulty in the connection between the two coats and at best it  
 > does not last for a very long time."  >  >  >  > Having said all this I
will say that my comments apply primarily to    > exterior finishes and I've
not yet experienced any problems with    > interior or protected locations.
But I should add that we also    > typically include a percentage of some glue
material in the lime    > plaster.  >  >  >  > John Glassford suggested the
use of lime/clay as an alternative and    > I think that it can be a very good
one. Much here depends upon the    > reaction between the clay soil and the
lime. Over the years I've    > watched varying reactions, some soils produce
exceptional results,    > others marginal. I recently cornered Harry Francis
who once worked    > for the American Lime Association while we happened to be
together    > recently in Washington DC. I told him that the using pH as an   
> indicator of the right type of mix was not proving true all of the    >
time. Like he always does Harry went home and searched his    > extensive
resources and just emailed me a paper that addresses some    > of those
variables particularly soils with high levels of potassium    > and sodium
carbonates. I haven't had time to really absorb the    > content, but if any
of you want a copy I would be happy to forward it.  >  >  >  > I've already
said more than I had intended, but to sum it up I    > would not suggest that
we recommend the use of lime plaster over    > earthen substrates as a general
practice. I would suggest that it    > be adopted only after some testing and
experimentation has been    > done and with a warning that the results are
always guaranteed.  >  >  >  > Bill  >  > On Oct 7, 2007, at 7:10 AM, Rikki
Nitzkin wrote:  >  >  >  >> Sorry to chime in so late...been busy. Its just
that I haven't    >> seen > anywhere  >  >> that in the responses to remind
Andy that it is very important to    >> > wet down  >  >> as well as scratch
the base layer of plaster before applying a new    >> > coat, and  >  >> if
the material is different (lime on clay in this case) really    >> rub > the 
>  >> first bit in so it binds well.  >  >>  >  >> Hope your problem has been
solved.  >  >>  >  >> Rikki Nitzkin  >  >> Aul=C3=A1s, Lleida, Espa=C3=B1a  > 
>> rikkinitzkin@...>  >> (0034)657 33 51 62  >  >>
www.casasdepaja.com (Red de Construcci=C3=B3n con Balas de Paja)  >  >>  >  >>
 >  >>> -----Mensaje original-----  >  >>> De: GSBN
[<a  target="_blank" href="mailto:GSBN@...";>mailto:GSBN@...] En nombre de Brian    >>> >> Hodge -  > 
>>> Anvill  >  >>> Enviado el: jueves, 27 de septiembre de 2007 22:20  >  >>>
Para: 'GSBN'  >  >>> Asunto: RE: GSBN:Re: Lime plaster problems  >  >>>  > 
>>> Hi Andy,  >  >>> I agree with John. We have been doing a very similar
thing for >>    >>> about 5  >  >>> years and have not found it necessary to
add the lime putty top    >>> >> coat. We  >  >>> have even done it without
chaff with a great deal of success.  >  >>>  >  >>> Regards  >  >>>  >  >>>
Brian  >  >>>  >  >>> Anvil Straw  >  >>>  >  >>> -----Original Message----- 
>  >>> From: GSBN [<a  target="_blank" href="mailto:GSBN@...";>mailto:GSBN@...] On Behalf Of John  > 
>>> Glassford  >  >>> Sent: Thursday, 27 September 2007 7:53 AM  >  >>> To:
GSBN  >  >>> Cc: Andy Horn  >  >>> Subject: Re: GSBN:Re: Lime plaster problems
 >  >>>  >  >>>  >  >>> G ' day Andy  >  >>>  >  >>> My two rands worth mate. 
>  >>>  >  >>> You will need to remove the lime coat and scratch up the earth
as    >>> >> others  >  >>> have said.  >  >>>  >  >>> I would then apply a
mix of earth/lime/sand and chaff or chopped    >>> >> straw.  >  >>>  >  >>>
All depends on the clay content of your earth but I would look at  >  >>>
something like this 3 parts soil 2 parts lime 3 parts sand 1 part    >>> >>
chaff.  >  >>> I use buckets for this mix. It works well and binds well with
the  >  >>> earthen render. Then if you want you can apply a finish coat of
lime  >  >>> render however I have not found that necessary in most cases >>  
 >>> except for  >  >>> look.  >  >>>  >  >>> You can see a house we renedered
with earth, then earth/lime/sand/   >>> >> chaff,  >  >>> then lime/sand,
here:  >  >>>  >  >>> <a  target="_blank" href="http://glassford.com.au/Jumbo.htm";>http://glassford.com.au/Jumbo.htm</a>  >  >>>  >  >>> No
delamination no cracks and it is nearly 6 years since we finished  >  >>>
there.  >  >>>  >  >>> Was in Cape Town a few weeks ago but did not have time
to see    >>> much it  >  >>> was a Rotary trip with Hout Bay. We will be back
next year for an  >  >>> extended visit, see you then.  >  >>>  >  >>> Kind
regards  >  >>> The Straw Wolf  >  >>> Huff 'n' Puff Constructions  >  >>>
<a  target="_blank" href="http://www.glassford.com.au/";>http://www.glassford.com.au/</a>  >  >>>  >  >>> 61 2 6927 6027  >  >>>  >  >>>
Mount Kilimanjaro Climb 28/8/07 <a  target="_blank" href="http://www.coolamonrotary.com/kili/";>http://www.coolamonrotary.com/kili/</a>  >  >>>
----  >  >>> For instructions on joining, leaving, or otherwise using the GSBN
   >>> >> list,  >  >>> send email to GSBN@...HELP in
the    >>> SUBJECT >> line.  >  >>>  >  >>> ----  >  >>>  >  >>>  >  >>>  > 
>>>  >  >>> ----  >  >>> For instructions on joining, leaving, or otherwise
using the GSBN    >>> >> list,  >  >>> send email to
GSBN@...HELP in the    >>> SUBJECT >> line.  >  >>>
----  >  >>  >  >> ----  >  >> For instructions on joining, leaving, or
otherwise using the GSBN    >> > list, send email to
GSBN@...HELP in the    >> > SUBJECT line.  >  >> ----
 >  >>  >  >  >  > Athena &amp; Bill Steen  >  > The Canelo Project  >  > HC1 Box
324  >  > Canelo/Elgin, AZ 85611  >  > absteen@...>  >
www.caneloproject.com  >  >  >  > ----  >  > For instructions on joining,
leaving, or otherwise using the GSBN    > list, send email to
GSBN@...HELP in the    > SUBJECT line. ----  >  >  >
______________________________________________________________________   > __ 
> Email and AIM finally together. You've gotta check out free AOL    > Mail! -
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---  > ----  > For instructions on joining, leaving, or otherwise using the
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> SUBJECT line.  > ----  >    Athena &amp; Bill Steen  The Canelo Project  HC1 Box
324  Canelo/Elgin, AZ 85611  absteen@...www.caneloproject.com     
----  For instructions on joining, leaving, or otherwise using the GSBN list,
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----------------------------------------------------------------------

Date: 12 Oct 2007 04:06:52 -0500
From: "Andre_de_Bouter" forum@...
Subject: Tom Rijven is is finaly available in Print (in French and English)


> Chris Magwood said:
> The walls with the least hollows? Those that have been "French dipped"
> which is why I like that method of building so much.
Tom Rijven, alias Tom Raven, alias The Straw Bale Gypsy, yes that
colorful Dutch guy with a heart of gold and fermet in his plaster that
dippes his bales mostly in France  has  at long last realized his dream
to put his SB-system in writing. And what's more, in wonderful pictures
and drawings too. We celebrated the birth of this baby 3 weeks ago in
one of his recent buildings and having read it I can only suggest you
buy it!

<a  target="_blank" href="http://www.gouttedesable.fr/product_info.php?cPath=22&amp;products_id=33";>http://www.gouttedesable.fr/product_info.php?cPath=22&amp;products_id=33</a>

Entre paille et terre
Par Tom Rijven
Published by Goutte de Sable <<a  target="_blank" href="http://www.gouttedesable.fr/";>http://www.gouttedesable.fr/</a>>, sept 2007
160 pages, couleur, ISBN 978-2-9523714-3-8

Andr#233#-only just recovered-de Bouter




----------------------------------------------------------------------

Date: 12 Oct 2007 06:32:13 -0500
From: "Andre_de_Bouter" forum@...
Subject: Re: GSBN: Earth plasters

Hello Lars,

I remember from an early mail of you about cellulose fiber that you
stated that too much of this fiber can lead to cracking due to the
swelling of the cellulose. How much paper do you use nowadays? Do you
also use it in outside (earth) finish plaster?

Bye,

Andr#233#
France

Lars Keller a #233#crit :
> Paper pulp has been a stable fibre addition to earthen plasters on many
> earthen plastered sb-constructions in Denmark the last 5 years.
> First it came about by listening to recommendations from ceramists
> applauding the reinforced clay.
> So when starting to use spraying machines that got clogged up by chopped up
> straw and the like paper pulp seemed to be the solution, and it was.
> Now we also use it when we plaster by hand, and for example in the
> claymortars used to some parts of building Finnish Mass Ovens (Masonry Ovens
> in the USofA).
>
> Lars
>
>
> 2007/10/11, Graeme North ecodesign@...:
>
>> We have found the addition of pulped paper as a fine fibre very very good.
>> Its made either from office paper or newspaper #173# it can be made by
>> throwing
>> soaked paper into a concrete mixer with lots of water and just letting it
>> roll until completely broken up , then draining off excess water before
>> use.
>> It gives a very fine fibre which is enormously beneficial in terms of
>> increasing strength, and durability of earth plasters. If it ferments a
>> bit
>> even better (all ferment seems to help earth plasters #173# using water
that
>> has
>> had a bit of straw left in it for a week or two to start to fizz is good
>> as
>> well)  #173# there appears to be some enzymic reaction that takes place
>> between
>> paper or ferment water and clay that helps workability and durability.
>>
>> Paper pulp eliminates dusting from earth plasters #173# helpful especially
if
>> the soil is a bit silty.  It also sticks well #173# we use it over
>> pre-compressed straw without meshing.
>> We also use it as a finishing plaster over drywall #173# a very nice finish
>> and
>> it sticks like ...glue.
>>
>> It is also very effective as an additive to earth bricks as well #173#
>> increases
>> robustness, durability, and also lowers density giving better insulation.
>>
>> The amount of paper pulp that can be added can be quite high  - we often
>> use
>> up to around 30% or so by volume to plaster , and have made mud bricks
>> with
>> up to 50% paper pulp #173# cardboard houses anyone?
>> I am currently looking at building with cob and mud brick mixes using
>> roughly 2 parts clay-soil, 2 parts wood shavings (long fibered rippings)
>> or
>> straw, and 1 part paper pulp #173# very tough, very light, easy to work,
and
>> looking promising.  Very good insulation, and very nice to use as gravity
>> increases #173# remember that there is plenty of evidence that gravity
doubles
>> in strength very thirty years.
>>
>> As to lime over earth #173# I#185#ve found it works well so far IF there is
good
>> keying and wetting #173# if the initial earth is a cob type mix with lots
of
>> (straw) fibre with plenty of fibres left hanging out of a rough surface,
>> then that is good too for tying the layers together.
>>
>> I#185#ve just lost a patch off a bit of a small experimental earth
plastered
>> and
>> whitewashed straw wall where the earth plasters layers were not keyed well
>> together. Keying is good.
>>
>> Best
>>
>>
>> Graeme,
>> Graeme North Architects,
>> 49 Matthew Road,
>> RD1, Warkworth,
>> New Zealand 0981
>> Ph/fax +64 (0)9  4259305
>>
>> ecodesign@...
>> www.ecodesign.co.nz
>>
>>
>>
>> --- StripMime Report -- processed MIME parts ---
>> multipart/alternative
>> text/plain (text body -- kept)
>> text/html
>> ---
>> ----
>> For instructions on joining, leaving, or otherwise using the GSBN list,
>> send email to GSBN@...HELP in the SUBJECT line.
>> ----
>>
>>
>>
>
>
>


----------------------------------------------------------------------

Date: 12 Oct 2007 10:06:31 -0500
From: Athena &amp; Bill Steen absteen@...
Subject: Re: GSBN:Re: Lime plaster problems

Any,
Tell you what.  I've sat and fiddled with pH meters, test strips,  
checked water, soil, etc. etc. etc.  In the end I found no substitute  
for simply trying different %s of lime with different soils.  For my  
use at home I finally found a soil that works really well and that  
was by accident when I wasn't even really trying.  All the soils we  
work with in this part of the world are fairly similar when it comes  
to pH as well as the water.  Why this one soil worked better than  
others is something I don't understand.  When I asked Harry Francis  
recently and asked him to explain the difference, he simply grinned  
and said "different chemistry."  What I do know is that the one soil  
that works well has a lot of naturally occurring gypsum and that is  
the only variable I can ID. Does that mean that all soils with gypsum  
will do the same? I wouldn't dare go so far.

The excessive winds you mention below by themselves are enough to  
trash and ruin the best of efforts. They alone may be responsible for  
everything you encountered.

As for old buildings with lime plaster I know one thing that has  
changed over the years is the lime.  Older limes were often fired on  
site in handmade kilns, etc.  Consequently the lime was less pure,  
more varied in color and usually softer and therefore more flexible.   
Today's lime is quite a different animal.  Consequently comparisons  
are at best difficult.

Bill
On Oct 10, 2007, at 3:05 PM, Andy Horn wrote:

> Dear Bill and others
> Much appreciate your well considered most informative response.
> Please do forward me the paper you were talking about thanks.
>
> I have done some investigation into the mineral content of the soil  
> talking
> to a knowledgeable engineer / farmer who said that the red  soils  
> we used,
> which are common to the area are generally quite acidic  .... He also
> explained that there used to be pine plantations in that specific  
> area and
> guessed the PH would be about 4,5 to 5. He also suggested that we  
> could
> check the PH of the water we used...if you think that will also  
> influence
> the results. He said with farming that meant they usually have to  
> add quite
> a lot of extra agricultural lime to the soil to help balance the  
> PH. If what
> you are saying is that with acidic soils/water we should use a  
> stronger lime
> mix ...then I guess our mix did not have enough lime in it. We used  
> 25% lime
> mix and probably should have used a 33% lime mix???? The mix was 2  
> parts
> soil, 7 parts sand and 3 parts lime. (The receipt I used was to  
> substitute 1
> part of the 3 parts of sand with the adobe mix)
>
> Our adobe mix was 2 parts soil and 1 parts sand and made excellent  
> bricks
> which were very well cured and the whole wall had had months of curing
> before any plastering.
>
> Apparently the soils (from Dolerite bedrock) apparently have a very  
> high
> aluminum content...not sure if that would have played a part in it???
>
> Not sure about the sodium carbonate levels but the potassium and  
> phosphate
> levels are very low (2-3 parts per million).
>
> The soils also have a fairly low P.I. and we did not experience much
> shrinkage. However we did wet the walls down very well before  
> applying the
> plaster and may have even over done the wetting of the walls  
> afterwards as I
> wanted to ensure the lime cured well......however this was negated  
> in the
> most part by the unusually occurring and excessive winds, which  
> occurred
> during the middle of the days over the period I was there. With the  
> pressure
> to get the job all done while I was up there, we pressed on,  
> instead of
> postponing the whole thing as in retrospect is what I should have  
> done.
>
> Furthermore in retrospect the keying was certainly not sufficient.
>
> Historically in the Cape, which I am more familiar with, most of  
> our old
> earth buildings (of which there are many 100 - 300 years old) were  
> always
> protected with a good coat of lime plaster. Sometimes however lime  
> plaster
> was not used and rather a cow dung earth plaster was used followed by
> regular coats of lime wash...though at the coast where we  
> experience strong
> wind driven rains a lime coating was the norm. No doubt our  
> forefathers knew
> a thing or two about lime that helped them get it right.....so I  
> have always
> had the greatest of confidence in lime plaster....up until now!
>
> Kind thanks
> Andy
>
> ECO DESIGN
> Architects &amp; Consultants
> A. R. HORN B.A.S. (UCT), B.Arch (UCT), Pr.Arch (SACAP),       MIA, CIA
> Telephone: 021 462 1614, Fax: 021 461 3198
> Cel: 082 67 62110
> 4th Flr, The Armoury
> 160 Sir Lowry Rd
> CAPE TOWN
> 7925
> web site:  HYPERLINK www.ecodesignarchitects.co.za
> www.ecodesignarchitects.co.za
> email: andy@...
>
> -----Original Message-----
> From: GSBN [<a  target="_blank" href="mailto:GSBN@...";>mailto:GSBN@...] On Behalf Of Athena  
> &amp; Bill
> Steen
> Sent: 07 October 2007 04:00 PM
> To: GSBN
> Subject: Re: GSBN:Re: Lime plaster problems
>
> I'll plead busy as well and before I made any comments I wanted to
> make sure they would be somewhat thorough.  There are a few things
> that have become evident to me over the years when it comes to lime
> over clay plaster.  In mho I would have to say that results are
> unpredictable and undependable.  I'm not saying it can't or doesn't
> work, but rather that outcomes vary widely. David Bainbridge
> mentioned in his earlier post the Getty people in Los Angeles as a
> resource.  I've made it a point to talk with them every few years
> about lime plaster and in particular their work with prickly pear
> cactus gel.  Anyhow in one of the last conversations we had they told
> me that there was a growing sentiment amidst the conservation
> community that the use of lime plaster over earth surfaces was not
> such a good idea.  They mentioned that although lime had better
> permeability than cement and allowed the earth to dry better when
> wet, it was still too different from an earthen substrate for it to
> work dependably.
>
> My experience basically says the same thing.  For me the whole issue
> comes down to what type of earth plaster is underneath.  Apparently
> some are much better than others and just what all the variables are
> I can't say.  I think it will take some time to get a better grasp on
> it.  Clearly I would suggest that if the substrate has a lot of clay
> there is a likely possibility that if water is absorbed through the
> lime plaster and passed on to the earth substrate then obviously the
> clay will expand and have a tendency to push the lime plaster away
> therefore causing the two to separate.  If the earth plaster is weak
> then the connection will break down over time.  So in short I guess
> what I'm saying is that the earth plaster has to be of a really good
> quality for any chance of success.  It needs to be strong and not
> have an overly high content of expansive clay.  Another very
> important piece is that the earthen plaster substrate must be
> thoroughly dry as earth plasters shrink when drying. If that process
> is not complete the earth will pull away from the lime plaster and
> leave it hanging in the air. And as others have pointed out the
> surface needs to be extremely well keyed for the lime to adhere.  I
> don't think you can under-do that aspect.  Additional measures like
> that of placing sharp jagged stones in the plaster would also help
> such as the practice of "rahuela" used in Mexico where stones are
> placed in the mortar joint between adobes.
>
> I think it was David that also mentioned the Japanesete We have
> worked closely with a pair of Japanese plasterers over recent years
> and it is important to note that the Japanese approach relies heavily
> on use of a glue when mixing what they call "Shikkui." Traditionally
> rice flour was used but was replaced with seaweed gel during a time
> of food shortages.  In general I would say that their plastering
> practices are far more meticulous than anything I've seen in this
> part of the world and in the words of the best plasterer from there
> that I can think of, "there is great difficulty in the connection
> between the two coats and at best it does not last for a very long
> time."
>
> Having said all this I will say that my comments apply primarily to
> exterior finishes and I've not yet experienced any problems with
> interior or protected locations.  But I should add that we also
> typically include a percentage of some glue material in the lime
> plaster.
>
> John Glassford suggested the use of lime/clay as an alternative and I
> think that it can be a very good one.  Much here depends upon the
> reaction between the clay soil and the lime. Over the years I've
> watched varying reactions, some soils produce exceptional results,
> others marginal.  I recently cornered Harry Francis who once worked
> for the American Lime Association while we happened to be together
> recently in Washington DC.  I told him that the using pH as an
> indicator of the right type of mix was not proving true all of the
> time.  Like he always does Harry went home and searched his extensive
> resources and just emailed me a paper that addresses some of those
> variables particularly soils with high levels of potassium and sodium
> carbonates.  I haven't had time to really absorb the content, but if
> any of you want a copy I would be happy to forward it.
>
> I've already said more than I had intended, but to sum it up I would
> not suggest that we recommend the use of lime plaster over earthen
> substrates as a general practice.  I would suggest that it be adopted
> only after some testing and experimentation has been done and with a
> warning that the results are always guaranteed.
>
> Bill
> On Oct 7, 2007, at 7:10 AM, Rikki Nitzkin wrote:
>
>> Sorry to chime in so late...been busy. Its just that I haven't seen
>> anywhere
>> that in the responses to remind Andy that it is very important to
>> wet down
>> as well as scratch the base layer of plaster before applying a new
>> coat, and
>> if the material is different (lime on clay in this case) really rub
>> the
>> first bit in so it binds well.
>>
>> Hope your problem has been solved.
>>
>> Rikki Nitzkin
>> Aulas, Lleida, Espana
>> rikkinitzkin@...
>> (0034)657 33 51 62
>> www.casasdepaja.com (Red de Construccion con Balas de Paja)
>>
>>
>>> -----Mensaje original-----
>>> De: GSBN [<a  target="_blank" href="mailto:GSBN@...";>mailto:GSBN@...] En nombre de Brian
>>> Hodge -
>>> Anvill
>>> Enviado el: jueves, 27 de septiembre de 2007 22:20
>>> Para: 'GSBN'
>>> Asunto: RE: GSBN:Re: Lime plaster problems
>>>
>>> Hi Andy,
>>> I agree with John. We have been doing a very similar thing for
>>> about 5
>>> years and have not found it necessary to add the lime putty top
>>> coat. We
>>> have even done it without chaff with a great deal of success.
>>>
>>> Regards
>>>
>>> Brian
>>>
>>> Anvil Straw
>>>
>>> -----Original Message-----
>>> From: GSBN [<a  target="_blank" href="mailto:GSBN@...";>mailto:GSBN@...] On Behalf Of John
>>> Glassford
>>> Sent: Thursday, 27 September 2007 7:53 AM
>>> To: GSBN
>>> Cc: Andy Horn
>>> Subject: Re: GSBN:Re: Lime plaster problems
>>>
>>>
>>> G ' day Andy
>>>
>>> My two rands worth mate.
>>>
>>> You will need to remove the lime coat and scratch up the earth as
>>> others
>>> have said.
>>>
>>> I would then apply a mix of earth/lime/sand and chaff or chopped
>>> straw.
>>>
>>> All depends on the clay content of your earth but I would look at
>>> something like this 3 parts soil 2 parts lime 3 parts sand 1 part
>>> chaff.
>>> I use buckets for this mix.  It works well and binds well with the
>>> earthen render.  Then if you want you can apply a finish coat of  
>>> lime
>>> render however I have not found that necessary in most cases
>>> except for
>>> look.
>>>
>>> You can see a house we renedered with earth, then earth/lime/sand/
>>> chaff,
>>> then lime/sand, here:
>>>
>>> <a  target="_blank" href="http://glassford.com.au/Jumbo.htm";>http://glassford.com.au/Jumbo.htm</a>
>>>
>>> No delamination no cracks and it is nearly 6 years since we finished
>>> there.
>>>
>>> Was in Cape Town a few weeks ago but did not have time to see  
>>> much it
>>> was a Rotary trip with Hout Bay.  We will be back next year for an
>>> extended visit, see you then.
>>>
>>> Kind regards
>>> The Straw Wolf
>>> Huff 'n' Puff Constructions
>>> <a  target="_blank" href="http://www.glassford.com.au/";>http://www.glassford.com.au/</a>
>>>
>>> 61 2 6927 6027
>>>
>>> Mount Kilimanjaro Climb 28/8/07 <a  target="_blank" href="http://www.coolamonrotary.com/kili/";>http://www.coolamonrotary.com/kili/</a>
>>> ----
>>> For instructions on joining, leaving, or otherwise using the GSBN
>>> list,
>>> send email to GSBN@...HELP in the SUBJECT
>>> line.
>>>
>>> ----
>>>
>>>
>>>
>>>
>>> ----
>>> For instructions on joining, leaving, or otherwise using the GSBN
>>> list,
>>> send email to GSBN@...HELP in the SUBJECT
>>> line.
>>> ----
>>
>> ----
>> For instructions on joining, leaving, or otherwise using the GSBN
>> list, send email to GSBN@...HELP in the
>> SUBJECT line.
>> ----
>>
>
> Athena &amp; Bill Steen
> The Canelo Project
> HC1 Box 324
> Canelo/Elgin, AZ 85611
> absteen@...
> www.caneloproject.com
>
>
> ----
> For instructions on joining, leaving, or otherwise using the GSBN  
> list, send
> email to GSBN@...HELP in the SUBJECT line.
> ----
>
>
> No virus found in this incoming message.
> Checked by AVG Free Edition.
> Version: 7.5.488 / Virus Database: 269.14.1/1050 - Release Date:  
> 2007/10/04
> 05:03 PM
>
>
> No virus found in this outgoing message.
> Checked by AVG Free Edition.
> Version: 7.5.488 / Virus Database: 269.14.1/1050 - Release Date:  
> 2007/10/04
> 05:03 PM
>
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Athena &amp; Bill Steen
The Canelo Project
HC1 Box 324
Canelo/Elgin, AZ 85611
absteen@...
www.caneloproject.com




----------------------------------------------------------------------

Date: 12 Oct 2007 10:23:48 -0500
From: Athena &amp; Bill Steen absteen@...
Subject: Re: GSBN: Japanese plasters

Andy,
When it comes to the sea it was traditionally boiled in water and  
then the concentrated water/gel added to the plaster.  However, it  
does come now in packages that can be added to the plaster much like  
boxed wheat paste. Rice was added as a cooked paste but that practice  
is basically discontinued so it is difficult to say how it was done.   
It is not added to lime/clay plaster, only the shikkui.  Actually I  
take that back, there are some clay plasters that it is added to as  
well. It is not applied like a glue to the wall, only mixed into the  
plaster.  As for Confort magazine I don't think you fill find that  
kind of detail in the text if you were to get it translated.  As for  
fiber, the shikkui contains hemp fiber, but it is the grade used to  
make clothing.  It is not short by any means, but very long and  
integrating it into the plaster is not an easy task.  As for the clay  
fibers, it is rice straw and I would guess that the only method would  
be screening it done to different mesh sizes once it has been  
initially chopped.  Without some very fancy processing device that  
would be the only way to make it happen.

Bill
On Oct 10, 2007, at 3:22 PM, Andy Horn wrote:

> Oh another thing Bill,
>
> A couple of years ago I was fortunate to travel to Japan and was  
> hugely
> impressed by their Shikkui plasters you talk about....even saw a  
> bamboo roof
> successfully plastered with it. But battled to find anyone to  
> explain the
> techniques they use.
>
> Can you explain more about the rice glue or seaweed glue they use/d???
>
> You say they mix it into their plasters....are those with lime clay  
> plasters
> or both???
>
> Is it like making a flour paste?
>
> You also seemed to imply they use it to get the lime to stick to  
> their earth
> walls/plaster layers.... is it put on like a glue just before  
> applying the
> lime or is it only added to the lime and or earth plaster layer/s?
>
> Sorry if that is too much to download over an email....and so maybe  
> you know
> a book where one can learn more about their techniques? I have 2  
> "Confort"
> earth building magazine but still need to find a translator.
>
> One thing I noticed was they used many very thin fine layers of  
> plaster. The
> other thing I could see was that the plaster seemed to have a very  
> high
> percentage of the finest of fibres imaginable mixed in with  
> it....which I
> imagine accounts for its resistance to rain and durability....many  
> of the
> plasters except the white "shikkui" appeared to be earth plasters  
> without
> lime, but invariably there was always plenty of very very fine  
> fibre when
> one examined it closely. Have you any idea how they made such fine  
> fibres
> and what it was made of ....I was lead to understand it was mostly  
> rice
> straw ....but could never understand how they shredded it so fine.
>
> Thanks
> Andy
>
>
> -----Original Message-----
> From: GSBN [<a  target="_blank" href="mailto:GSBN@...";>mailto:GSBN@...] On Behalf Of Athena  
> &amp; Bill
> Steen
> Sent: 07 October 2007 04:00 PM
> To: GSBN
> Subject: Re: GSBN:Re: Lime plaster problems
>
> I'll plead busy as well and before I made any comments I wanted to
> make sure they would be somewhat thorough.  There are a few things
> that have become evident to me over the years when it comes to lime
> over clay plaster.  In mho I would have to say that results are
> unpredictable and undependable.  I'm not saying it can't or doesn't
> work, but rather that outcomes vary widely. David Bainbridge
> mentioned in his earlier post the Getty people in Los Angeles as a
> resource.  I've made it a point to talk with them every few years
> about lime plaster and in particular their work with prickly pear
> cactus gel.  Anyhow in one of the last conversations we had they told
> me that there was a growing sentiment amidst the conservation
> community that the use of lime plaster over earth surfaces was not
> such a good idea.  They mentioned that although lime had better
> permeability than cement and allowed the earth to dry better when
> wet, it was still too different from an earthen substrate for it to
> work dependably.
>
> My experience basically says the same thing.  For me the whole issue
> comes down to what type of earth plaster is underneath.  Apparently
> some are much better than others and just what all the variables are
> I can't say.  I think it will take some time to get a better grasp on
> it.  Clearly I would suggest that if the substrate has a lot of clay
> there is a likely possibility that if water is absorbed through the
> lime plaster and passed on to the earth substrate then obviously the
> clay will expand and have a tendency to push the lime plaster away
> therefore causing the two to separate.  If the earth plaster is weak
> then the connection will break down over time.  So in short I guess
> what I'm saying is that the earth plaster has to be of a really good
> quality for any chance of success.  It needs to be strong and not
> have an overly high content of expansive clay.  Another very
> important piece is that the earthen plaster substrate must be
> thoroughly dry as earth plasters shrink when drying. If that process
> is not complete the earth will pull away from the lime plaster and
> leave it hanging in the air. And as others have pointed out the
> surface needs to be extremely well keyed for the lime to adhere.  I
> don't think you can under-do that aspect.  Additional measures like
> that of placing sharp jagged stones in the plaster would also help
> such as the practice of "rahuela" used in Mexico where stones are
> placed in the mortar joint between adobes.
>
> I think it was David that also mentioned the Japanesete We have
> worked closely with a pair of Japanese plasterers over recent years
> and it is important to note that the Japanese approach relies heavily
> on use of a glue when mixing what they call "Shikkui." Traditionally
> rice flour was used but was replaced with seaweed gel during a time
> of food shortages.  In general I would say that their plastering
> practices are far more meticulous than anything I've seen in this
> part of the world and in the words of the best plasterer from there
> that I can think of, "there is great difficulty in the connection
> between the two coats and at best it does not last for a very long
> time."
>
> Having said all this I will say that my comments apply primarily to
> exterior finishes and I've not yet experienced any problems with
> interior or protected locations.  But I should add that we also
> typically include a percentage of some glue material in the lime
> plaster.
>
> John Glassford suggested the use of lime/clay as an alternative and I
> think that it can be a very good one.  Much here depends upon the
> reaction between the clay soil and the lime. Over the years I've
> watched varying reactions, some soils produce exceptional results,
> others marginal.  I recently cornered Harry Francis who once worked
> for the American Lime Association while we happened to be together
> recently in Washington DC.  I told him that the using pH as an
> indicator of the right type of mix was not proving true all of the
> time.  Like he always does Harry went home and searched his extensive
> resources and just emailed me a paper that addresses some of those
> variables particularly soils with high levels of potassium and sodium
> carbonates.  I haven't had time to really absorb the content, but if
> any of you want a copy I would be happy to forward it.
>
> I've already said more than I had intended, but to sum it up I would
> not suggest that we recommend the use of lime plaster over earthen
> substrates as a general practice.  I would suggest that it be adopted
> only after some testing and experimentation has been done and with a
> warning that the results are always guaranteed.
>
> Bill
> On Oct 7, 2007, at 7:10 AM, Rikki Nitzkin wrote:
>
>> Sorry to chime in so late...been busy. Its just that I haven't seen
>> anywhere
>> that in the responses to remind Andy that it is very important to
>> wet down
>> as well as scratch the base layer of plaster before applying a new
>> coat, and
>> if the material is different (lime on clay in this case) really rub
>> the
>> first bit in so it binds well.
>>
>> Hope your problem has been solved.
>>
>> Rikki Nitzkin
>> Aulas, Lleida, Espana
>> rikkinitzkin@...
>> (0034)657 33 51 62
>> www.casasdepaja.com (Red de Construccion con Balas de Paja)
>>
>>
>>> -----Mensaje original-----
>>> De: GSBN [<a  target="_blank" href="mailto:GSBN@...";>mailto:GSBN@...] En nombre de Brian
>>> Hodge -
>>> Anvill
>>> Enviado el: jueves, 27 de septiembre de 2007 22:20
>>> Para: 'GSBN'
>>> Asunto: RE: GSBN:Re: Lime plaster problems
>>>
>>> Hi Andy,
>>> I agree with John. We have been doing a very similar thing for
>>> about 5
>>> years and have not found it necessary to add the lime putty top
>>> coat. We
>>> have even done it without chaff with a great deal of success.
>>>
>>> Regards
>>>
>>> Brian
>>>
>>> Anvil Straw
>>>
>>> -----Original Message-----
>>> From: GSBN [<a  target="_blank" href="mailto:GSBN@...";>mailto:GSBN@...] On Behalf Of John
>>> Glassford
>>> Sent: Thursday, 27 September 2007 7:53 AM
>>> To: GSBN
>>> Cc: Andy Horn
>>> Subject: Re: GSBN:Re: Lime plaster problems
>>>
>>>
>>> G ' day Andy
>>>
>>> My two rands worth mate.
>>>
>>> You will need to remove the lime coat and scratch up the earth as
>>> others
>>> have said.
>>>
>>> I would then apply a mix of earth/lime/sand and chaff or chopped
>>> straw.
>>>
>>> All depends on the clay content of your earth but I would look at
>>> something like this 3 parts soil 2 parts lime 3 parts sand 1 part
>>> chaff.
>>> I use buckets for this mix.  It works well and binds well with the
>>> earthen render.  Then if you want you can apply a finish coat of  
>>> lime
>>> render however I have not found that necessary in most cases
>>> except for
>>> look.
>>>
>>> You can see a house we renedered with earth, then earth/lime/sand/
>>> chaff,
>>> then lime/sand, here:
>>>
>>> <a  target="_blank" href="http://glassford.com.au/Jumbo.htm";>http://glassford.com.au/Jumbo.htm</a>
>>>
>>> No delamination no cracks and it is nearly 6 years since we finished
>>> there.
>>>
>>> Was in Cape Town a few weeks ago but did not have time to see  
>>> much it
>>> was a Rotary trip with Hout Bay.  We will be back next year for an
>>> extended visit, see you then.
>>>
>>> Kind regards
>>> The Straw Wolf
>>> Huff 'n' Puff Constructions
>>> <a  target="_blank" href="http://www.glassford.com.au/";>http://www.glassford.com.au/</a>
>>>
>>> 61 2 6927 6027
>>>
>>> Mount Kilimanjaro Climb 28/8/07 <a  target="_blank" href="http://www.coolamonrotary.com/kili/";>http://www.coolamonrotary.com/kili/</a>
>>> ----
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>>> line.
>>>
>>> ----
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>>>
>>>
>>>
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>>> ----
>>
>> ----
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>> list, send email to GSBN@...HELP in the
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>>
>
> Athena &amp; Bill Steen
> The Canelo Project
> HC1 Box 324
> Canelo/Elgin, AZ 85611
> absteen@...
> www.caneloproject.com
>
>
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Athena &amp; Bill Steen
The Canelo Project
HC1 Box 324
Canelo/Elgin, AZ 85611
absteen@...
www.caneloproject.com




----------------------------------------------------------------------

Date: 12 Oct 2007 10:27:21 -0500
From: Athena &amp; Bill Steen absteen@...
Subject: Re: GSBN: Earth plasters

Graeme,
Couple of things. First of all (laughing), plastering in NZ I think  
is a tad bit different than dehydrated parts of the world such as  
where I live. I suspect Andy's part of the world is in the dehydrated  
category.

But on to what you said about fermenting plaster. I have found that  
the longer any earth plaster ages the better it seems to get.  
Especially this applies to those containing some fiber whether it be  
straw or paper.  Even for short periods of time we've had large  
batches of clay and straw plaster rise like bread dough, quite  
amazing.  The only objectionable thing about longer periods is that  
there is a definite organic odor that comes with it.  Personally it  
doesn't bother me, but others don't get overly excited about it.  To  
see if I can help those who are sensitive we've started some  
experimental batches with EM, a product known as Essential  
Microorganisms to see if it alters the process somewhat.

Anyhow, what I like about the fermented mixes is that the character  
of the mix changes entirely.  It is hard to describe, but it becomes  
much more pliable, plastic, easy to work and the breakdown of fiber I  
suspect makes it less susceptible to mold when drying in wetter  
conditions.

The only down side about adding too much paper for an interior  
plaster is that you're going to sacrifice thermal mass and since that  
is an impt ingredient when it comes to the performance of a SB  
building it would seem we don't want to sacrifice that.

Bill
On Oct 10, 2007, at 2:05 PM, Graeme North wrote:

> We have found the addition of pulped paper as a fine fibre very  
> very good.
> Its made either from office paper or newspaper  it can be made by  
> throwing
> soaked paper into a concrete mixer with lots of water and just  
> letting it
> roll until completely broken up , then draining off excess water  
> before use.
> It gives a very fine fibre which is enormously beneficial in terms of
> increasing strength, and durability of earth plasters. If it  
> ferments a bit
> even better (all ferment seems to help earth plasters  using water  
> that has
> had a bit of straw left in it for a week or two to start to fizz is  
> good as
> well)  - there appears to be some enzymic reaction that takes place  
> between
> paper or ferment water and clay that helps workability and durability.
>
> Paper pulp eliminates dusting from earth plasters  helpful  
> especially if
> the soil is a bit silty.  It also sticks well  we use it over
> pre-compressed straw without meshing.
> We also use it as a finishing plaster over drywall  a very nice  
> finish and
> it sticks like ...glue.
>
> It is also very effective as an additive to earth bricks as well   
> increases
> robustness, durability, and also lowers density giving better  
> insulation.
>
> The amount of paper pulp that can be added can be quite high  - we  
> often use
> up to around 30% or so by volume to plaster , and have made mud  
> bricks with
> up to 50% paper pulp  cardboard houses anyone?
> I am currently looking at building with cob and mud brick mixes using
> roughly 2 parts clay-soil, 2 parts wood shavings (long fibered  
> rippings) or
> straw, and 1 part paper pulp  very tough, very light, easy to work,  
> and
> looking promising.  Very good insulation, and very nice to use as  
> gravity
> increases  remember that there is plenty of evidence that gravity  
> doubles
> in strength very thirty years.
>
> As to lime over earth  I1ve found it works well so far IF there is  
> good
> keying and wetting  if the initial earth is a cob type mix with  
> lots of
> (straw) fibre with plenty of fibres left hanging out of a rough  
> surface,
> then that is good too for tying the layers together.
>
> I1ve just lost a patch off a bit of a small experimental earth  
> plastered and
> whitewashed straw wall where the earth plasters layers were not  
> keyed well
> together. Keying is good.
>
> Best
>
>
> Graeme,
> Graeme North Architects,
> 49 Matthew Road,
> RD1, Warkworth,
> New Zealand 0981
> Ph/fax +64 (0)9  4259305
>
> ecodesign@...
> www.ecodesign.co.nz
>
>
>
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> For instructions on joining, leaving, or otherwise using the GSBN  
> list, send email to GSBN@...HELP in the  
> SUBJECT line.
> ----
>

Athena &amp; Bill Steen
The Canelo Project
HC1 Box 324
Canelo/Elgin, AZ 85611
absteen@...
www.caneloproject.com




----------------------------------------------------------------------

Date: 12 Oct 2007 18:52:29 -0500
From: MattsMyhrman@...
Subject: Re: GSBN:Re: Lime plaster problems

In a message dated 10/10/2007 1:17:11 PM US Mountain Standard Time,
andy@...:

> Sometimes however lime plaster
> was not used and rather a cow dung earth plaster was used followed by
> regular coats of lime wash...though at the coast where we experience strong
> wind driven rains a lime coating was the norm.

I believe that many of the cob buildings on the southern coast of England
(Devon?) used several (maybe 4-5 initially) coats of lime wash.  It was
considered somewhat sacrificial, and was followed up, after a year or two,
with a
couple more coats.  After that, another coat every couple of years.  Maybe
Barbara
Jones can check in on this  one, and also tell us whether lime wash over cob
or earth plaster has traditionally been used anywhere in the British Isles
where they experience driving rains coming in off the sea (up on the northwest
coast of Scotland?).


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Date: 12 Oct 2007 19:57:56 -0500
From: MattsMyhrman@...
Subject: Re: Pulped Paper as a Fiber Source

In a message dated 10/10/2007 2:09:04 PM US Mountain Standard Time,
ecodesign@...:

> We have found the addition of pulped paper as a fine fibre very very good.
> Its made either from office paper or newspaper &amp;shy; it can be made by
> throwing
> soaked paper into a concrete mixer with lots of water and just letting it
> roll until completely broken up , then draining off excess water before use.
> It gives a very fine fibre which is enormously beneficial in terms of
> increasing strength, and durability of earth plasters.

Here's a different use of newspaper-sourced fiber.

The top part of my strawbale igloo/office first got a well-scratched layer of
earth plaster.  The "scratching" was done with a commercial tool that gives
flat-topped ridges and flat-bottomed valleys that have straight, vertical
sides
from the top of the ridges down to the bottom of the valleys.

I then troweled on an approximately 1/4 inch thick layer of a mixture of
free, recylcled latex paint and cellulose ceiling insulation (essentially
shredded
newspaper).  To test the bonding between this cello-latex and the underlying
earth layer, I applied some onto a similarly scratched earth test tile.  When
I peeled off the cello-latex, the separation occured not where the c-l met the
earth, but, rather, slightly within the earth base, leaving the entire bottom
of the c-l covered with a thin layer of earth.

The final layer was a thin, rolled on coat of UV-resistant elastomeric roof
paint.

The performance so far has been outstanding, keeping everything inside
absolutely dry.  Totally non-air-permeable, but tighter than a frog's ass, and
that's water-tight.

Matts (feeling the fiber) Myhrman




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Date: 12 Oct 2007 20:09:25 -0500
From: Tom Hahn tomhahn@...
Subject: Re: GSBN:Re: Pulped Paper as a Fiber Source

Sheer poetry, Matts... (pun intended)

That made me chuckle pretty hard...

Tom Hahn


>... keeping everything inside
>absolutely dry.  Totally non-air-permeable, but tighter than a frog's ass,
and
>that's water-tight.
>
>Matts (feeling the fiber) Myhrman


----------------------------------------------------------------------

Date: 12 Oct 2007 21:10:10 -0500
From: Graeme North ecodesign@...
Subject: Re: GSBN: Earth plasters

> Hi Bill and others - thanks
> 
> I agree totally that long mixing and aging is good for plasters.
> 
> And sometimes yes we long for a bit of dehydrated climate - esp when the
mould
> starts growing on us!
> 
> An earth/straw house actually makes one hell of a difference in comfort in
> this soggy climate - no more condensation on even single glazed windows
(with
> passive solar design to trap some heat into the mass of the house) - no more
> mould on items such as leather shoes - plenty of spiders to share the house
> with - 
> 
> Be really keen to hear how you find EM - I1ve just discovered it for the
> garden - it seems to be magic - it may take away that good old fermenting
> smell.
> 
> As to significant thermal mass in straw houses - I1m a bit of a fan myself
of
> straw for exterior walls, earth for interior walls and floor, and don1t try
> and pursue much out of the earth plasters where it is going to be pretty
> minimal anyway - and of course only the final plaster of only a few mm thick
> needs the paper additive anyway come to that.
> 
> And  - I1ve never found swelling of cellulose fibres to be an issue, even
with
> quite high percentages - its really saturated when we use it - esp if its
been
> sitting a while - and anecdotally - a building near here that burned down
had
> the firemen puzzled because the dry wall was in much better shape than the
> firemen expected to see after a fire - the clay/paper plaster had added
> significant extra protection.
> 
> Finally - Limewash over clay- yes toughens up the surface no end - -however
I
> have found on experimental and historic walls that IF the wall gets so wet
> that water gets into the underlying earth plaster, differential swelling
takes
> place and the whitewash spalls off in my humble experience.  If the walls
are
> getting this wet probably something wrong with the design anyway.
> 
> 
> Graeme
> 
> 
> 
> Couple of things. First of all (laughing), plastering in NZ I think
> is a tad bit different than dehydrated parts of the world such as
> where I live. I suspect Andy's part of the world is in the dehydrated
> category.
> 
> But on to what you said about fermenting plaster. I have found that
> the longer any earth plaster ages the better it seems to get.
> Especially this applies to those containing some fiber whether it be
> straw or paper.  Even for short periods of time we've had large
> batches of clay and straw plaster rise like bread dough, quite
> amazing.  The only objectionable thing about longer periods is that
> there is a definite organic odor that comes with it.  Personally it
> doesn't bother me, but others don't get overly excited about it.  To
> see if I can help those who are sensitive we've started some
> experimental batches with EM, a product known as Essential
> Microorganisms to see if it alters the process somewhat.
> 
> Anyhow, what I like about the fermented mixes is that the character
> of the mix changes entirely.  It is hard to describe, but it becomes
> much more pliable, plastic, easy to work and the breakdown of fiber I
> suspect makes it less susceptible to mold when drying in wetter
> conditions.
> 
> The only down side about adding too much paper for an interior
> plaster is that you're going to sacrifice thermal mass and since that
> is an impt ingredient when it comes to the performance of a SB
> building it would seem we don't want to sacrifice that.
> 
> Bill






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