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GSBN: Digest for 1/8/03



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


-> Re: GSBN:Jeff Ruppert and clay tests
     by billc_lists@...
-> Re: GSBN:mesh reinforcing for earth plasters
     by stafford@...
-> Re: GSBN:mesh reinforcing for earth plasters
     by Paul Lacinski paul@...
-> Re: GSBN:Jeff Ruppert and clay tests
     by Paul Lacinski paul@...
-> Re: GSBN:Jeff Ruppert and clay tests
     by Athena & Bill Steen absteen@...


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

Date: 8 Jan 2003 04:00:43 -0600
From: billc_lists@...
Subject: Re: GSBN:Jeff Ruppert and clay tests

Tim OK wrote:

>We have moved to using either lime or earth
>plaster or lime plaster. though we tend, like many of you to add a top lime
>coat on the exterior of our earth plaster. Recently I was afforded an
>opportunity take apart some of these assemblies. (more on that later) most
>notably the earth to lime connection was the week link and I would assume
>extreme weather would like to pop the thin lime coat off. for this reason
>(and the mold that Paul mentioned) I am interested in getting a small amount
>of lime into the mix and work it to the surface then scratch so that I might
>have a better chance of getting a lasting bond. I have not noticed much
>degradation of the brick clays but site soils do all kinds of things that I
>don't fully get yet.


Interestingly, there's a parallel discussion going on in the 
replacement strawbale list (http://groups.yahoo.com/groups/sb-r-us) 
between Bill Steen and Harry (whose last name I can't remember, but 
his email is CALXA@...he is among the Plaster Gods) under 
the subject line "new group" that details exactly what is happening 
to cause that weak link between the earth and lime.

The short version is that too small amount of lime works as a 
flocculant, essentially turning your clay into silt.  I think that's 
likely what is happening at the earth/lime boundary.  You may want to 
re-think (or at least test on a wall you don't care about) your 
theory of working a small amt of lime into the surface & then 
scratching.

"Using too little lime increases the permability of clays by flocculation of
the clay particles.....we call this modification.... A good use here is 1 - 2
% lime on  a hard pan soil - unsuitable for agriculture.... now treated with
lime becomes friable.....and very suitable for plant growth.... "

Once you hit a certain % lime (which varies a bit depending upon the 
clay), you start making cement.

"I think a lime clay mix with sufficient lime so the pH is above 12 would be
fine - Now you have made a hydraulic lime........ Most clays need above 5%
lime by weight to achive this high pH level.. some as much as 8%."

"BUT ---  if only small amounts of lime are added to the clays, then I think
you have converted the clay into a silt thru flocculation; resulting in a
very permeable material...not suitable for a coating...."


- -- 
Bill Christensen
http://sustainablesources.com/contact/

Green Building Professionals Directory: http://directory.sustainablesources.com
Sustainable Building Calendar: http://SustainableSources.com/calendar/
Green Real Estate: http://SustainableSources.com/realestate/
Straw Bale Registry: http://sbregistry.sustainablesources.com/
Books/videos/software: http://bookstore.sustainablesources.com/


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

Date: 8 Jan 2003 14:36:52 -0600
From: stafford@...
Subject: Re: GSBN:mesh reinforcing for earth plasters

Bruce,

Another mesh idea you proposed to me at one time was fish netting. 
Haven't had an occasion to try it, but you should be able to find plenty 
new or used in the Bay Area.

Chris

Lars Keller wrote:

>One of the easily accessible, nonexpensive meshes we use, is the pp-mesh used
to wrap the roundbales. When you can find the strawbale you can oftenmost find
the mesh as well.
>
>Lars Keller
>
>~~~
>
>Bruce King ecobruce@... wrote:
>  
>
>>G'Day  Baleheads -
>>
>>Here in sunny Califronia, we are very much in the heat of
>>the straw bale
>>test program, and have encountered a small problem that we
>>hope some of
>>y'all can help with.
>>
>>We are determined to devise an earthen-plastered straw bale
>>wall that can be
>>used even in high seismic/strict building code areas like
>>San Francisco.
>>Even with plenty of straw or other fibers in the plaster
>>mix, however, we
>>cannot make it work without some sort of straps or mesh
>>reinforcing tying
>>the top plate across the wall to the foundation.  We have
>>investigated a
>>number of lightweight plastic meshes, and a number of coir
>>and hemp meshes,
>>and pretty much ruled out metal mesh because it will
>>presumably corrode
>>pretty fast in the earthen plaster.
>>
>>The coir and hemp meshes didn't work because they were too
>>fuzzy and too
>>tightly woven to allow the plaster to be applied through
>>them onto the bale
>>wall.  We cannot just lay them over a base plaster coat and
>>then plaster
>>again over that, as they need to be anchored at the
>>foundation.
>>
>>Ideally, someone can help us locate a plastic, hemp, coir or
>>other natural
>>fiber mesh that is open enough to plaster through, is
>>readily available (or
>>at least not TOO hard to get), and has some reasonable
>>amount of strength.
>>
>>Any suggestions will be much appreciated - please hit the
>>old "Reply to all"
>>button if you do have an idea, and send it asap.
>>
>>thanks,
>>
>>Bruce King, PE
>>Director, Ecological Building Network
>>209 Caledonia St.
>>Sausalito, CA 94965
>>(415) 331-7630
>>fax 332-4072
>>www.ecobuildnetwork.org
>>bruce@ ecobuildnetwork.org
>>
>>----
>>For instructions on joining, leaving, or otherwise using the
>>GSBN list, send email to GSBN@...
>>HELP in the SUBJECT line.
>>----
>>
>>    
>>
>
>
>~~~
>
>Lars Keller
>Friland 12 B
>Feldballe
>8410 Ronde
>Danmark
>
>0045-20240505
>larskeller@...
>~~~
>----
>For instructions on joining, leaving, or otherwise using the GSBN list, send
email to GSBN@...HELP in the SUBJECT line.
>----
>
>
>.
>
>  
>




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- --------------090809010205080106030108
Content-Type: text/html; charset=us-ascii
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<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
  <meta http-equiv="Content-Type" content="text/html;charset=ISO-8859-1">
  <title></title>
</head>
<body>
Bruce, 
 
Another mesh idea you proposed to me at one time was fish netting. Haven't
had an occasion to try it, but you should be able to find plenty new or used
in the Bay Area. 
 
Chris 
 
Lars Keller wrote: 
<blockquote type="cite"
 cite="mid20030107224036.JVPP3799.fepA.post.tele.dk@fepK.im.tele.dk">
  <pre wrap="">One of the easily accessible, nonexpensive meshes we use, is
the pp-mesh used to wrap the roundbales. When you can find the strawbale you
can oftenmost find the mesh as well.

Lars Keller

~~~

Bruce King <a class="moz-txt-link-rfc2396E"
href="mailto:ecobruce@sbcglobal.net";>ecobruce@...</a> wrote:
  </pre>
  <blockquote type="cite">
    <pre wrap="">
G'Day  Baleheads -

Here in sunny Califronia, we are very much in the heat of
the straw bale
test program, and have encountered a small problem that we
hope some of
y'all can help with.

We are determined to devise an earthen-plastered straw bale
wall that can be
used even in high seismic/strict building code areas like
San Francisco.
Even with plenty of straw or other fibers in the plaster
mix, however, we
cannot make it work without some sort of straps or mesh
reinforcing tying
the top plate across the wall to the foundation.  We have
investigated a
number of lightweight plastic meshes, and a number of coir
and hemp meshes,
and pretty much ruled out metal mesh because it will
presumably corrode
pretty fast in the earthen plaster.

The coir and hemp meshes didn't work because they were too
fuzzy and too
tightly woven to allow the plaster to be applied through
them onto the bale
wall.  We cannot just lay them over a base plaster coat and
then plaster
again over that, as they need to be anchored at the
foundation.

Ideally, someone can help us locate a plastic, hemp, coir or
other natural
fiber mesh that is open enough to plaster through, is
readily available (or
at least not TOO hard to get), and has some reasonable
amount of strength.

Any suggestions will be much appreciated - please hit the
old "Reply to all"
button if you do have an idea, and send it asap.

thanks,

Bruce King, PE
Director, Ecological Building Network
209 Caledonia St.
Sausalito, CA 94965
(415) 331-7630
fax 332-4072
<a class="moz-txt-link-abbreviated"
href="http://www.ecobuildnetwork.org";>www.ecobuildnetwork.org</a>
bruce@ ecobuildnetwork.org

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For instructions on joining, leaving, or otherwise using the
GSBN list, send email to <a class="moz-txt-link-abbreviated"
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- ----

    </pre>
  </blockquote>
  <pre wrap=""><!---->

~~~

Lars Keller
Friland 12 B
Feldballe
8410 R&oslash;nde
Danmark

0045-20240505
<a class="moz-txt-link-abbreviated"
href="mailto:larskeller@livinghouses.net";>larskeller@...
~~~
- ----
For instructions on joining, leaving, or otherwise using the GSBN list, send
email to <a class="moz-txt-link-abbreviated"
href="mailto:GSBN@...";>GSBN@... with
HELP in the SUBJECT line.
- ----


.

  </pre>
</blockquote>
 
</body>
</html>

- --------------090809010205080106030108--



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

Date: 8 Jan 2003 18:56:57 -0600
From: Paul Lacinski paul@...
Subject: Re: GSBN:mesh reinforcing for earth plasters

Bruce,

We have used fiberglass mesh (think dryvit) extensively in both 
earthen and lime plasters, and it works great.  The tricky part is 
attaching it to the structure- it needs to be wrapped around a wooden 
or other strip, and the strip nailed in place.  If you just try to 
staple or nail it, it pulls apart.  It's also expensive, about $90 
for a 37" by 150 foot roll.  But we use it exclusively on exterior 
transitions between bales and wooden members, because metal lath just 
doesn't work well around here.

I have mostly used a brand called Fiberlath, but Sto and Dryvit make 
similar products.  The trick is finding a material with large enough 
openings.  The usual synthetic stucco meshes have holes of roughly 
1/8"; not big enough.  The mesh with larger holes- 3/8 or 1/2"- is 
usually designated as a "heavy duty mesh."  They use it for extra 
reinforcing of areas that are expected to take unusual abuse, like 
impacts.  You should be able to find it by calling around to masonry 
supply yards.  It's a bit difficult to find out this way (synthetic 
stucco, thankfully, is one form of uglification that has not caught 
on in clapboard country) but I think it should not be difficult in CA.

Our usual technique is to spray or trowel on a coat of plaster, work 
the mesh in, and then apply more to completely imbed it.  We do both 
of these coats at once, because if the mesh is simply troweled into 
the surface of the first coat, its natural springiness can cause it 
to jump back out.  We also want to make sure that the mesh layer 
doesn't become the weak point of connection between two coats.

Best of luck,

Paul
- -- 
Paul Lacinski
Amy Klippenstein
GreenSpace Collaborative
Sidehill Farm
PO Box 107
463 Main St.
Ashfield, MA 01330 USA
01-413-628-3800


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

Date: 8 Jan 2003 18:57:21 -0600
From: Paul Lacinski paul@...
Subject: Re: GSBN:Jeff Ruppert and clay tests

Responses below to emails from both Bruce and Tim:

>
>Clay by itself is the binder in earthen plasters, and as we all know, works
>really well when done right.  Lime, on the other hand (and portland cement)
>will destroy clay's binding force by deflocculating the little water-loving
>grains.  That's why highway builders, especially in wet climate/clay soil
>places like the UK, like to use lime to both dry and deflocculate soils
>before laying down their beloved asphalt paving.

I'm not sure, but I think you have it backwards- I think the lime 
causes the clay particles to glom together.  My copy of the lime 
books are out on loan, at the moment, however.  I do know that if you 
have a clay plaster going in the mixer and you start adding lime, you 
eventually hit a point where the mix suddenly gets very stiff, stiff 
enough that if you don't immediately add water the paddles are likely 
to stop turning and the breaker to pop.  At this point the mix also 
becomes very greasy.  I'm not sure, but I think this is a decent 
field test for the minimum amount of lime to add to a given batch of 
clay.

>That's also why Bill
>reported LOSING strength in earthen bricks when he added lime;  his binder
>wasn't binding, which will always put a hitch in ol' Bill's giddyup.  But
>that's only the short term (one or two month) picture . . .
>
>  . . . The long term picture has the lime carbonation and low-grade
>pozzolanic reaction between clay and lime coming into play, and I'd guess
>the strength/durability would keep on growing over the years.

This has been our experience, exactly.  The clay/lime mix is 
noticably stronger after 4 or 6 months than after 1 month.  At 2 
weeks or 1 month, it may well be weaker than the clay-only mix.


>Recently I was afforded an
>opportunity take apart some of these assemblies. (more on that later) most
>notably the earth to lime connection was the week link and I would assume
>extreme weather would like to pop the thin lime coat off. for this reason
>(and the mold that Paul mentioned) I am interested in getting a small amount
>of lime into the mix and work it to the surface then scratch so that I might
>have a better chance of getting a lasting bond. I have not noticed much
>degradation of the brick clays but site soils do all kinds of things that I
don't fully get yet.

Everyplace I go, I bring my building geek self along, and look for 
delaminating plaster.  It's not hard to find, but I have never found 
it in a situation where the backing coats were scratched, regardless 
of material.  This doesn't mean it can't happen; but it's clear that 
scratching greatly reduces the likelihood.


When we next plaster (March) I'll make a raft of samples, and send 
them along for testing.  I can also send the 2x2x8 blocks that Tim 
recommends. The best may be to test at 1 month, two months, and 4 
months.

Thanks,

Paul

- -- 
Paul Lacinski
Amy Klippenstein
GreenSpace Collaborative
Sidehill Farm
PO Box 107
463 Main St.
Ashfield, MA 01330 USA
01-413-628-3800


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

Date: 8 Jan 2003 22:33:13 -0600
From: Athena & Bill Steen absteen@...
Subject: Re: GSBN:Jeff Ruppert and clay tests


I have posted this to both groups as the material contained here has 
appeared in both forums.
I think I can clear up some of the confusion at least when it comes to 
Bruce's comments about lime weakening clay by deflocculating it.  What 
he says is true in that small amounts of lime agglomerates the clay 
particles and makes them resemble silt sand size particles.  Basically 
it trashes the clay.  It can't bind anymore nor does it hold onto 
water.  It's a long explanation that doesn't need to happen here at the 
moment.  Basically the intent is to take away its ability to expand and 
shrink so drastically.  The big "however," in this case is that if one 
adds enough lime to get the pH of the clay/lime mix up in the vicinity 
of 12+, then different things happen, the silica in the clay begins to 
break down into gel and recombines with the calcium to make a new 
substance that is stronger and more water resistant the original clay.  
Then, instead of modifying the clay, it truly becomes a "stabilized" 
material.  The key is adding enough lime, anything short of that makes 
it weaker.  Now when Bruce talks about our early experiments producing 
weak bricks, that was true, but somewhere back a ways we essentially 
figured out that what was needed was more lime.  Harry Francis says 
somewhere around 10% by weight is about right if you're just shooting 
in the dark and not using pH meters or doing tests on individual 
samples.  My experience at this point says that seems about right.  
We've got what I would consider some incredible samples of the stuff at 
the moment that I am very pleased with, there isn't much more you can 
ask of a plaster at least in this environment.  So I haven't ploughed 
through all of Paul Lacinski's earlier post but I would suspect that I 
would agree with most of what he has said there.

For the meantime, if you want more info on this, I posted the article 
Harry wrote for issue no. 22 of TLS (Lime Plaster) which deals with the 
Stabilization of Earth with Lime.  If you have issue 22 still around, 
you can find it there.  Otherwise, it is under the files section of the 
SB-r-us group site.

And I guess whoever is interested in testing this stuff ought to talk 
with Harry cuz he claims to have had in his hands samples of lime 
stabilized clay that had compressive strengths exceeding 1500 psi.  Now 
what to say, either Harry is suffering from confusion, bad memory, 
wishful thinking or there might be a chance that he is telling the 
truth.  Just in case he is, I think we ought to find out what 
particular combination produced those results, where, when and what 
have you.  Or at least so it would seem to me.

One concern I have always had about this particular combination is 
wondering how efficient it would be in not letting liquid moisture pass 
through to the straw.  Clay obviously likes to hold onto it and not let 
it go, cements, limes by themselves appear ready to give it up at a 
moment's notice.  So I have wondered where the clay/lime mixes would 
stand on that scale.  According to Harry (one more time) what happens 
is that as the calcium silicate forms, the interparticle spaces are 
filled with crystalline grow of CaS making the material impermeable 
....filling up the voids, and making the new material as water tight as 
was the clay....and yet at the same time, clay and lime combined do not 
attract moisture.  Having attempted to soak and erode some of the walls 
we have here, it always seemed to be the case, that they were doing 
exceptionally well in resisting the uptake of water and apparently 
that's the case.
On Wednesday, January 8, 2003, at 05:35 PM, Paul Lacinski wrote:

> Responses below to emails from both Bruce and Tim:
>
>>
>> Clay by itself is the binder in earthen plasters, and as we all know, 
>> works
>> really well when done right.  Lime, on the other hand (and portland 
>> cement)
>> will destroy clay's binding force by deflocculating the little 
>> water-loving
>> grains.  That's why highway builders, especially in wet climate/clay 
>> soil
>> places like the UK, like to use lime to both dry and deflocculate 
>> soils
>> before laying down their beloved asphalt paving.
>
> I'm not sure, but I think you have it backwards- I think the lime 
> causes the clay particles to glom together.  My copy of the lime books 
> are out on loan, at the moment, however.  I do know that if you have a 
> clay plaster going in the mixer and you start adding lime, you 
> eventually hit a point where the mix suddenly gets very stiff, stiff 
> enough that if you don't immediately add water the paddles are likely 
> to stop turning and the breaker to pop.  At this point the mix also 
> becomes very greasy.  I'm not sure, but I think this is a decent field 
> test for the minimum amount of lime to add to a given batch of clay.
>
>> That's also why Bill
>> reported LOSING strength in earthen bricks when he added lime;  his 
>> binder
>> wasn't binding, which will always put a hitch in ol' Bill's giddyup.  
>> But
>> that's only the short term (one or two month) picture . . .
>>
>>  . . . The long term picture has the lime carbonation and low-grade
>> pozzolanic reaction between clay and lime coming into play, and I'd 
>> guess
>> the strength/durability would keep on growing over the years.
>
> This has been our experience, exactly.  The clay/lime mix is noticably 
> stronger after 4 or 6 months than after 1 month.  At 2 weeks or 1 
> month, it may well be weaker than the clay-only mix.
>
>
>> Recently I was afforded an
>> opportunity take apart some of these assemblies. (more on that later) 
>> most
>> notably the earth to lime connection was the week link and I would 
>> assume
>> extreme weather would like to pop the thin lime coat off. for this 
>> reason
>> (and the mold that Paul mentioned) I am interested in getting a small 
>> amount
>> of lime into the mix and work it to the surface then scratch so that 
>> I might
>> have a better chance of getting a lasting bond. I have not noticed 
>> much
>> degradation of the brick clays but site soils do all kinds of things 
>> that I
> don't fully get yet.
>
> Everyplace I go, I bring my building geek self along, and look for 
> delaminating plaster.  It's not hard to find, but I have never found 
> it in a situation where the backing coats were scratched, regardless 
> of material.  This doesn't mean it can't happen; but it's clear that 
> scratching greatly reduces the likelihood.
>
>
> When we next plaster (March) I'll make a raft of samples, and send 
> them along for testing.  I can also send the 2x2x8 blocks that Tim 
> recommends. The best may be to test at 1 month, two months, and 4 
> months.
>
> Thanks,
>
> Paul
>
> -- 
> Paul Lacinski
> Amy Klippenstein
> GreenSpace Collaborative
> Sidehill Farm
> PO Box 107
> 463 Main St.
> Ashfield, MA 01330 USA
> 01-413-628-3800
> ----

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



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I have posted this to both groups as the material contained here has
appeared in both forums.

I think I can clear up some of the confusion at least when it comes to
Bruce's comments about lime weakening clay by deflocculating it.  What
he says is true in that small amounts of lime agglomerates the clay
particles and makes them resemble silt sand size particles.  Basically
it trashes the clay.  It can't bind anymore nor does it hold onto
water.  It's a long explanation that doesn't need to happen here at
the moment.  Basically the intent is to take away its ability to
expand and shrink so drastically.  The big "however," in this case is
that if one adds enough lime to get the pH of the clay/lime mix up in
the vicinity of 12+, then different things happen, the silica in the
clay begins to break down into gel and recombines with the calcium to
make a new substance that is stronger and more water resistant the
original clay.  Then, instead of modifying the clay, it truly becomes
a "stabilized" material.  The key is adding enough lime, anything
short of that makes it weaker.  Now when Bruce talks about our early
experiments producing weak bricks, that was true, but somewhere back a
ways we essentially figured out that what was needed was more lime. 
Harry Francis says somewhere around 10% by weight is about right if
you're just shooting in the dark and not using pH meters or doing
tests on individual samples.  My experience at this point says that
seems about right.  We've got what I would consider some incredible
samples of the stuff at the moment that I am very pleased with, there
isn't much more you can ask of a plaster at least in this environment. 
So I haven't ploughed through all of Paul Lacinski's earlier post but
I would suspect that I would agree with most of what he has said
there.  


For the meantime, if you want more info on this, I posted the article
Harry wrote for issue no. 22 of TLS (Lime Plaster) which deals with
the Stabilization of Earth with Lime.  If you have issue 22 still
around, you can find it there.  Otherwise, it is under the files
section of the SB-r-us group site.


And I guess whoever is interested in testing this stuff ought to talk
with Harry cuz he claims to have had in his hands samples of lime
stabilized clay that had compressive strengths exceeding 1500 psi. 
Now what to say, either Harry is suffering from confusion, bad memory,
wishful thinking or there might be a chance that he is telling the
truth.  Just in case he is, I think we ought to find out what
particular combination produced those results, where, when and what
have you.  Or at least so it would seem to me.


One concern I have always had about this particular combination is
wondering how efficient it would be in not letting liquid moisture
pass through to the straw.  Clay obviously likes to hold onto it and
not let it go, cements, limes by themselves appear ready to give it up
at a moment's notice.  So I have wondered where the clay/lime mixes
would stand on that scale.  According to Harry (one more time) what
happens is that as the calcium silicate forms, the interparticle
spaces are filled with crystalline grow of CaS making the material
impermeable ....filling up the voids, and making the new material as
water tight as was the clay....and yet at the same time, clay and lime
combined do not attract moisture.  Having attempted to soak and erode
some of the walls we have here, it always seemed to be the case, that
they were doing exceptionally well in resisting the uptake of water
and apparently that's the case.

On Wednesday, January 8, 2003, at 05:35 PM, Paul Lacinski wrote:


<excerpt>Responses below to emails from both Bruce and Tim:


<excerpt>

Clay by itself is the binder in earthen plasters, and as we all know,
works

really well when done right.  Lime, on the other hand (and portland
cement)

will destroy clay's binding force by deflocculating the little
water-loving

grains.  That's why highway builders, especially in wet climate/clay
soil

places like the UK, like to use lime to both dry and deflocculate soils

before laying down their beloved asphalt paving.

</excerpt>

I'm not sure, but I think you have it backwards- I think the lime
causes the clay particles to glom together.  My copy of the lime books
are out on loan, at the moment, however.  I do know that if you have a
clay plaster going in the mixer and you start adding lime, you
eventually hit a point where the mix suddenly gets very stiff, stiff
enough that if you don't immediately add water the paddles are likely
to stop turning and the breaker to pop.  At this point the mix also
becomes very greasy.  I'm not sure, but I think this is a decent field
test for the minimum amount of lime to add to a given batch of clay.


<excerpt>That's also why Bill

reported LOSING strength in earthen bricks when he added lime;  his
binder

wasn't binding, which will always put a hitch in ol' Bill's giddyup. 
But

that's only the short term (one or two month) picture . . .


 . . . The long term picture has the lime carbonation and low-grade

pozzolanic reaction between clay and lime coming into play, and I'd
guess

the strength/durability would keep on growing over the years.

</excerpt>

This has been our experience, exactly.  The clay/lime mix is noticably
stronger after 4 or 6 months than after 1 month.  At 2 weeks or 1
month, it may well be weaker than the clay-only mix.



<excerpt>Recently I was afforded an

opportunity take apart some of these assemblies. (more on that later)
most

notably the earth to lime connection was the week link and I would
assume

extreme weather would like to pop the thin lime coat off. for this
reason

(and the mold that Paul mentioned) I am interested in getting a small
amount

of lime into the mix and work it to the surface then scratch so that I
might

have a better chance of getting a lasting bond. I have not noticed much

degradation of the brick clays but site soils do all kinds of things
that I

</excerpt>don't fully get yet.


Everyplace I go, I bring my building geek self along, and look for
delaminating plaster.  It's not hard to find, but I have never found
it in a situation where the backing coats were scratched, regardless
of material.  This doesn't mean it can't happen; but it's clear that
scratching greatly reduces the likelihood.



When we next plaster (March) I'll make a raft of samples, and send
them along for testing.  I can also send the 2x2x8 blocks that Tim
recommends. The best may be to test at 1 month, two months, and 4
months.


Thanks,


Paul


- -- 

Paul Lacinski

Amy Klippenstein

GreenSpace Collaborative

Sidehill Farm

PO Box 107

463 Main St.

Ashfield, MA 01330 USA

01-413-628-3800

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list, send email to GSBN@...HELP in the
SUBJECT line.  ----



</excerpt><fontfamily><param>Helvetica</param>Athena & Bill Steen

The Canelo Project

HC1 Box 324

Canelo/Elgin, AZ 85611

absteen@...

www.caneloproject.com</fontfamily>


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