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GSBN: Digest for 1/7/03



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-> TLS / clay plaster
     by bruce king ecobruce@...
-> Re: GSBN:Jeff Ruppert and clay tests
     by "tim Owen-Kennedy" timok@...
-> mesh reinforcing for earth plasters
     by Bruce King ecobruce@...
-> Re: GSBN:mesh reinforcing for earth plasters
     by Chris Magwood cmagwood@...
-> Re:  GSBN:mesh reinforcing for earth plasters
     by Strawnet@...
-> Mesh reinforcing for earth plasters+
     by bainbridge bainbrid@...
-> Re: GSBN:mesh reinforcing for earth plasters
     by larskeller@...


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

Date: 7 Jan 2003 09:36:00 -0600
From: bruce king ecobruce@...
Subject: TLS / clay plaster



Chris Magwood wrote:

> Thanks for your postings recently about clay plasters . . .
> 
> I am thinking about theming a near-future issue of TLS "The Case for Clay",
> in which case I'd love to use these exchanges you've had on GSBN as a
> starting place for a discussion forum on clay plasters which would form the
> core of the issue. Would you all be open to your postings being used in
> this way (of course, you'd be allowed to edit yourselves!)?

Sure,

Bruce



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

Date: 7 Jan 2003 12:16:44 -0600
From: "tim Owen-Kennedy" timok@...
Subject: Re: GSBN:Jeff Ruppert and clay tests

Happy New year all,

OK, I've been waiting until I had enough time to weigh in on the clay chat,
but that may never happen so here is a rushed response. Hopefully I'll
follow up sooner or later with more detail and questions.

most importantly, Paul, or anyone else who wants to, if you are going to
send cubes also send 6 bricks 2x2x8in. that way we can also test for modulus
of rupture.

we've tried (on buildings) 20 different mixes of earth based plaster and
more than 15 soil types and we're still pretty low on the curve. We used to
add up to 1 part lime per clay but because of the variability in how it
performed with different soils. 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.

After working with the lime-earth plasters at 1:1 I feel we are actually
making a weak Lime plaster rather than a stranger earth plaster - that's why
we're testing it. I have cast samples of a 10% lime in earth mix and a 50%
lime in earth mix which we will break this month as part of the EBNet
testing program. We are also sending samples of each mix to John Straube to
measure the permeability. (Bruce, we were mixing them for John and decided
to cast cubes as a bonus). Also, Paul, what lime are you using and how are
you preparing it?

We have also been working with crusher fines of late (the same source that
is used for most rammed earth in Northern California). we have been able to
make a good mix with adding only small amounts of brick clay and a healthy
amount of straw. My main concern is determining the silt content of the
fines because I think the bulk of the silt in the fines masquerades as clay.
we've been happiest with two mixes: 4 crusher fines, 1 brick clay, 2 sand, 3
chopped straw; for sprayed plaster, and 6 crusher fines, 1 brick clay, and
3-4 long straw, for one coat hand applied mixes or for cob. We mix both in
our 10 yd horizontal silage mixer (we bought the smaller one) and the second
mix we just through whole bales in and it chops it pretty well.

I have done cylinder tests of the second mix that show a possible 400 psi. I
am about to test it more formally because we may have had too much local
containment on the cylinders.

For those of you who want to submit "food for Jaws", we will be happy to
accept them and test them if we can but no guarantees.

I feel that the Earth plaster that we are using in the testing program is
fairly weak though not unrepresentative of what I've seen. As Bill and
Athena noted when they were out it is fairly silty as are most of our clay's
in CA. As the King has intended we should have a fairly simple protocol for
testing any earth plaster when we're done and that's what's really exiting
to me.

more later...

be well,

tim



Tim Owen-Kennedy
Vital Systems
Natural Building and Design, inc.
3212 Jefferson St. #406 Napa, CA  94558


- ----- Original Message -----
From: "Bruce King" ecobruce@...
To: "GSBN" GSBN@...; "Tim Kennedy"
timok@...
Cc: howe@...
Sent: Monday, January 06, 2003 5:19 PM
Subject: Re: GSBN:Jeff Ruppert and clay tests


> on 1/6/03 11:41 AM, Paul Lacinski at paul@...
wrote:
>
> > Many thanks for this test.  We use clay and lime plasters almost
exclusively
> > now, but I am still uncomfortable promoting them without solid data . .
.
> >  . . . My concern about this mix is the degree to which vapor
permeability
> > may be reduced.  In Building with Lime, Michael Wingate and Stafford
Holmes
> > talk about a low-grade cement being formed by the reaction between the
lime
> > and some of the minerals in the clay.  This is only one of a set of
reactions
> > that supposedly combine to form the harder plaster.  The
others-flocculation
> > (sticking-together) of the clay particles, pozzolanic reactions between
the
> > lime and minerals in the clay, standard carbonation in the lime- don't
seem as
> > if they would cause significant reductions in vapor permeability.
Though the
> > nature of these reactions would certainly vary according to the
different
> > clays and limes used, it would be useful to have some general sense of
how
> > this plaster would perfom, compared with the clay-only version.
>
> Paul, Jeff, and all y'all -
>
> Bill Steen (and others) and I have had a slow running conversation on this
> subject over the years.  There are so many kinds of clay, occuring in so
> many proportions in various natural or bagged soils, and also so many
kinds
> of lime with varying degress of hydraulicity (ie similarity to portland
> cement) that it's maddening to try and extract generalizations about
> lime-clay behaviour.
>
> But hey, while we're young and foolish, let's try!
>
> 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.  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.  I would
also
> guess that vapor permeability would decrease, but not very much.
>
> > So, I hope you find this useful.  If anyone has any ideas or needs more
> > specific thoughts or mixes, please let me know.  And maybe someone who
is more
> > laboratory-oriented than myself wants to crush a few samples?  I'd send
you a
> > virtual kiss for that, which you are absolutely free to refuse!
>
> Well, gee, Paul, yer mighty cute and all, but I'll pass on the smooch.  We
> do, however, have a reasonably accurate rig now set up (part of the EBNet
> testing program) that can crush plaster cubes.  We affectionately call
this
> little hummer  "Jaws", and would be happy to put it to use.  How about,
> Paul, you make up a dozen or more 2" cubes each of your clay plaster and
> lime-clay plaster, let them set a month or two, and send them out to the
> address below;  we'll squish 'em and report the results.  Paul, if you do,
> write EVERYTHING down: mix proportions (including water), description of
> ingredients, cast dates, method of curing (under a tarp inside in
> conditioned space is ideal), etc.
>
> By the way, on Jeff Ruppert's website, he makes reference to the "300 to
400
> psi strengths" obtained in the EBNet program.  Due to the bonehead error
of
> an arithmetic-impaired engineer who shall remain nameless, those numbers
are
> erroneous in that said engineer forgot to divide by 4 (ie the four square
> inch area of the 2" cube).  Anyway, the numbers (87 to 200 psi) are now
> correctly reported on the EBNet website, and said engineer has been
stripped
> of his pocket protector for three months.
>
> Happy New Year to all
> at least as much as is possible under the shadow of a Bush,
>
> 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
>

>
>



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

Date: 7 Jan 2003 14:37:43 -0600
From: Bruce King ecobruce@...
Subject: mesh reinforcing for earth plasters



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



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

Date: 7 Jan 2003 15:07:16 -0600
From: Chris Magwood cmagwood@...
Subject: Re: GSBN:mesh reinforcing for earth plasters

>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.


Bruce,

Haven't tried it with earth plaster, but the plastic mesh from called
Cintoflex D from Tenax http://www.tenax.net is very thin, very strong and
might do the trick.  Works better than anything we've tried for lime and
lime/cement plasters. Worth trying, anyway.

Chris


***************************

Chris Magwood / Camel's Back Straw Bale Construction
http://www.strawhomes.ca

Interested in bale building? Have you subscribed to
The Last Straw Journal?
You should!
 http://www.strawhomes.com


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

Date: 7 Jan 2003 15:27:11 -0600
From: Strawnet@...
Subject: Re:  GSBN:mesh reinforcing for earth plasters

Bruce

I would take a look at geogrid materials - they are a specific woven (as 
opposed to non-woven, mat-like geotextiles) geotextile that is typically 
made of polypropylene or high density polyesther in grids with very large 
openings - 1-1/2" or larger used for soil stabilization and they're 
really strong. Enkagrid is one brand that I've seen and there are quite a 
few others. As I recall, some also have different axial characteristics 
that might or might not matter.  There are also some fencing materials 
that are made of similar materials that might work, but the geogrids and 
geotextiles, since they are used structurally in soil and slope 
stabilization generally have been thoroughly tested and so have good 
product engineering data available, giving you an easier path to 
calculating their contribution to structural reinforcement. 

Hope that helps you find what you're looking for...

David

David Eisenberg
Director
Development Center for Appropriate Technology (DCAT)
P.O. Box 27513
Tucson, Arizona 85726-7513 USA
(520) 624-6628
(520) 798-3701 Fax
David@...
strawnet@...(direct personal e-mail)
www.dcat.net

=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=
The way to subvert the dominant paradigm is to have 
more fun than they have and make sure they know it!
=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=




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

Date: 7 Jan 2003 16:23:01 -0600
From: bainbridge bainbrid@...
Subject: Mesh reinforcing for earth plasters+


Natural fiber mesh and other fabrics in interesting formulas that 
might be worth trying are sold for erosion control. Coir nets are 
stiff and long lasting, the erosion control netting sold at Home 
Depot is jute (cheap) - also a possibility but not stiff and doesn't 
last as long.

The coir (coconut fiber) mesh comes in different weaves

http://www.geotextiles.org/classification.htm
http://www.beltonindustries.com/erosion_long.html		see 
	dekowe400specs

www.rolanka.com/ - not working today.

There is quite a bit of engineering data on these also
see for example
http://www.geosource.com/gsyn/bio/bt3.htm


Full exposed to weather and sun the coir net lasts 3-7 years in San Diego.

Jute is often sold as 48" width x 225 ft. length rolls (100 sq.yds./900
sq.ft.)
http://www.griffithbag.com/nursery/erosion.html
http://www.spec-net.com.au/maccaferri/erosion.htm

Tenax makes a wide variety of materials in plastic
http://www.tenaxus.com/

A polypropylene mesh might be good...these are sold in garden supply 
for bird and deer protection
http://www.northcoastweb.com/deerfence/deercontrolframe.html
330 ft x 7.5 ft for $225

Dave
- -- 
David Bainbridge
Environmental Studies Coordinator
CAS
Alliant International University
10455 Pomerado Road
San Diego, CA 92131

Fax (858) 635-4730
Ph (858) 635-4616
http://academic.alliant.edu/bainbridge/
http://www.sustainableenergy.org/resources/technologies/solar_passive.htm
http:SustainableSources.com

The future isn't something hidden in a corner. The future is 
something we build in the present. Paulo Freire


******************* NOTE *******************
There may be important message content
contained in the following MIME Information.
********************************************


- ------------------ MIME Information follows ------------------

- --============_-1170145369==_ma============
Content-Type: text/plain; charset="us-ascii" ; format="flowed"

<<<<<< See above "Message Body" >>>>>>

- --============_-1170145369==_ma============
Content-Type: text/html; charset="us-ascii"

<!doctype html public "-//W3C//DTD W3 HTML//EN">
<html><head><style type="text/css"><!--
blockquote, dl, ul, ol, li { margin-top: 0 ; margin-bottom: 0 }
 --></style><title>Mesh reinforcing for earth
plasters+</title></head><body>
Natural fiber mesh and other fabrics in interesting formulas that
might be worth trying are sold for erosion control. Coir nets are
stiff and long lasting, the erosion control netting sold at Home
Depot is jute (cheap) - also a possibility but not stiff and doesn't
last as long.
 
The coir (coconut fiber) mesh comes in different weaves
 
http://www.geotextiles.org/classification<span
></span>.htm
http://www.beltonindustries.com/erosion_l<span
></span>ong.html<x-tab>      
</x-tab><x-tab>       
</x-tab><i>see<x-tab>    
</x-tab>dekowe400specs</i>
<font face="Arial" size="+2" color="#008000"> </font>
<font size="-1" color="#008000">www.rolanka.com/</font> - not
working today.
 
There is quite a bit of engineering data on these also
see for example
http://www.geosource.com/gsyn/bio/bt3.htm<span
></span>
 
 
Full exposed to weather and sun the coir net lasts 3-7 years in
San Diego.
 
Jute is often sold as<font size="-1" color="#000000"> 48"
width x 225 ft. length rolls (100 sq.yds./900 sq.ft.)</font><font
face="Helvetica" size="+3" color="#000000"> 
</font>http://www.griffithbag.com/nursery/erosio<span
></span>n.html
http://www.spec-net.com.au/maccaferri/ero<span
></span>sion.htm
 
Tenax makes a wide variety of materials in plastic
http://www.tenaxus.com/
 
A polypropylene mesh might be good...these are sold in garden
supply for bird and deer protection
http://www.northcoastweb.com/deerfence/de<span
></span>ercontrolframe.html
330 ft x 7.5 ft for $225
 
Dave

<font color="#000000">--  
David Bainbridge 
Environmental Studies Coordinator 
CAS 
Alliant International University 
10455 Pomerado Road 
San Diego, CA 92131 
 
Fax (858) 635-4730 
Ph (858) 635-4616 
http://academic.alliant.edu/bainbridge/ 
http://www.sustainableenergy.org/resource<span
></span>s/technologies/solar_passive.htm  
http:SustainableSources.com</font>
<font color="#000000"> </font>
<font color="#000000">The future isn't something hidden in a
corner. The future is something we build in the present. Paulo
Freire</font><font face="Times New Roman" size="+3"
color="#000000"></font>
</body>
</html>
- --============_-1170145369==_ma============--


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

Date: 7 Jan 2003 16:58:04 -0600
From: larskeller@...
Subject: Re: GSBN:mesh reinforcing for earth plasters

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@...
~~~


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

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