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-> Re: GSBN:Re Thermal Properties of (french dipped) Straw Bale Walls
     by Rene Dalmeijer rene.dalmeijer@...
-> RE:  dipped Bale Walls
     by "Andy Horn" andy@...
-> Re: GSBN:Re Thermal Properties of Straw Bale Walls
     by stoneandstraw@...
-> Re: GSBN:Re Thermal Properties of Straw Bale Walls
     by stoneandstraw@...
-> Re: GSBN:Re Thermal Properties of Straw Bale Walls
     by Bob Theis bob@...
-> Re: GSBN:Colombia
     by Martin Hammer mfhammer@...
-> Re: GSBN:Colombia
     by Catherine Wanek cat@...
-> Re: Darrel Deboer's nomination
     by Bruce King ecobruce@...
-> Re: GSBN:Re Thermal Properties of Straw Bale Walls
     by "Andre_de_Bouter" forum@...
-> Re: GSBN:Re Thermal Properties of Straw Bale Walls
     by john@...
-> Re: GSBN:Re Thermal Properties of Straw Bale Walls
     by stoneandstraw@...
-> Re: GSBN:Colombia
     by billc billc_lists@...
-> Re: GSBN:Re Thermal Properties of Straw Bale Walls
     by billc billc_lists@...
-> Re: GSBN:Re Thermal Properties of Straw Bale Walls
     by john@...
-> Darrell DeBoer
     by Joy Bennett mbenn1035@...


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

Date: 24 May 2007 02:16:34 -0500
From: Rene Dalmeijer rene.dalmeijer@...
Subject: Re: GSBN:Re Thermal Properties of (french dipped) Straw Bale Walls

Chris,

I fully support you in this it is essential that the dipped bales are 
used quite rapidly after dipping. This is a messy business but working 
with two people to lift and place the bales makes a big difference. The 
bales tend to fit in much better the need for stuffing joints is almost 
diminished to zero.

Another tip once the bales are in place a tamping of the still tacky 
bale surfaces with a plank and a hammer will align and flatten the bale 
surface to a great extent. The best technique is to lay the plank 
across the bale joints and then tamp. To work effectively the clay rich 
slip should still be quite moist.

Rene
On May 24, 2007, at 03:50, cmagwood@...:

> I'd like to kick in on the "French dipped" method, as I
> believe they do a great job of helping to provide a really
> good "seal" across the entire face of the wall. It would
> make sense that if dipped bales are left to dry before
> being stacked that they wouldn't work as well, but they
> shouldn't go in when dried, but when slightly tacky. Then
> the straw/clay that goes in the gaps bonds very well to
> the bales and makes, for me, the best wall surface going.
>
> Chris
>
>>
>> Marty suggested that the 'French dipped' bales might give
>> a good tight
>> fit between the bales. My experience is the opposite. If
>> the bales are
>> dried after being dipped the diped sides get rock hard and
>> do not
>> compress. If the bales are placed before they are dried
>> there is more
>> chance for settling but this is a messier way of going
>> about.
>>
>> As for the test Nehemiah mentioned where the top was
>> stuffed. A
>> suggestions (if such a test is ever to be repeated) is to
>> compress and
>> stuff the wall from below with car jacks between the
>> 'foundation' and
>> botom plate'.
>>
>> Bye,
>>
>> Andre "drop that bale" de Bouter
>>
>>
>>
>> John Swearingen a ecrit :
>>>> Straw-clay seems the best material for this purpose,
>>>> although too
>>>> much clay
>>> might increase conductive heat loss in the stuffed area.
>>> <
>>>
>>> ...for several other reasons, too.  When straw is
>>> stuffed in joints it's
>>> relatively loose and so provides a ready channel for
>>> moisture into the
>>> depths of the wall.  Straw-clay will form a seal against
>>> moisture
>>> entering
>>> the joints between the bales.  In addition, it stops air
>>> infiltration and
>>> can be screeded off to make a flat plain for plaster,
>>> thereby reducing
>>> the
>>> occurance of cracks that result from abrupt changes in
>>> the thickess of
>>> the
>>> plaster.  Also, it's fun to get dirty....
>>>
>>> "Hurlen" John Swearingen
>>>
>>> On 5/19/07, Martin Hammer mfhammer@... wrote:
>>>>
>>>> Nehemiah -
>>>>
>>>> Good explanations.
>>>>
>>>> You talked about the straw-stuffed gaps at the top and
>>>> sides of a
>>>> wall as
>>>> being places where convective losses could occur.  So
>>>> I'll add the
>>>> thermal
>>>> importance of stuffing vertical joints/gaps between
>>>> bales for the same
>>>> reason of limiting convective losses.  (This would also
>>>> be important
>>>> between
>>>> bales and "posts" that go mostly or all the way through
>>>> the thickness of
>>>> the
>>>> wall.  I've seen I-joists or steel trusses used this
>>>> way.)
>>>>
>>>> Straw-clay seems the best material for this purpose,
>>>> although too much
>>>> clay
>>>> might increase conductive heat loss in the stuffed
>>>> area.  Horizontal
>>>> joints
>>>> between bales don't seem to be an issue because the
>>>> weight of the bales
>>>> appear to cause the surfaces to lock in well enough to
>>>> limit air
>>>> movement
>>>> between them (although the French dipped bales might
>>>> seal that joint
>>>> even
>>>> better, and bales on-edge probably nestle together
>>>> better than
>>>> laid-flat).
>>>>
>>>> Then there's always the question of what material is
>>>> between the
>>>> bottom of
>>>> the plates, and what the insulative qualities of the
>>>> roof bearing
>>>> assembly
>>>> are.  And then there's the ceiling/roof, and the
>>>> windows/doors, and the
>>>> amount of infiltration throughout, and . . . . .
>>>>
>>>> Martin Hammer
>>>>
>>>>
>>>>> John,
>>>>>
>>>>> I did not see a response from Andrew.  Was that off
>>>> list?  I am always
>>>>> interested in what new or other information people
>>>> have on the thermal
>>>>> properties of straw bale construction.  Care to share
>>>> his input?
>>>>> Also, your Q about how compaction affects R-value is
>>>> a potent
>>>> question.  If
>>>>> hot box testing wasn't so expensive and time
>>>> consuming, or if there
>>>> were
>>>>> funders lined up to pay for it, I'd already have an
>>>> answer for
>>>> you.  There
>>>>> are a number of confounding factors, so until someone
>>>> has done the
>>>> actual
>>>>> research, we can throw around lots of theories.
>>>>> For example, it is air that creates the insulation
>>>> value of almost
>>>>> everything used for wall insulation.  ,,,not the spun
>>>> glass, not the
>>>> solid
>>>>> portions of the foam, not the cellulose, not the
>>>> straw.
>>>> Therefore, if
>>>>> bales are compacted too much, one would expect the
>>>> insulation value to
>>>> go
>>>>> down.  But, what is "too much?"  If bales are too
>>>> loose, then the air
>>>> can
>>>>> circulate in the air pockets and research HAS shown
>>>> that this can lead
>>>> to
>>>>> convective currents that lead in turn, to a dramatic
>>>> drop in
>>>> R-value.  That
>>>>> was one of the causes (we think) for the relatively
>>>> low R-values in
>>>> the
>>>> ATI
>>>>> lab tests in Fresno, CA.  Once we stacked the bales
>>>> in the hot box
>>>> wall
>>>>> opening, and compressed them as they'd be in a
>>>> building wall, we had a
>>>> six
>>>>> inch gap at the top.  We filled it with straw as
>>>> tightly as we could,
>>>> but
>>>>> we are not match for either a baler or truckers'
>>>> strap tightening
>>>> levers,
>>>>> so we KNOW that the top (where the greatest amount of
>>>> heat exchange
>>>> would
>>>>> naturally occur anyway) was much looser than the rest
>>>> of the
>>>> wall.  Ditto
>>>>> the sides, though those gaps were significantly
>>>> smaller (so perhaps,
>>>> harder
>>>>> to compact straw into).
>>>>> Further, though in theory greater compaction - after
>>>> the optimal
>>>> point -
>>>>> will lead to a decreasing R-value, no tests have yet
>>>> shown that to be
>>>> the
>>>>> case.  Perhaps we just haven't found the optimal
>>>> compression force
>>>> yet.
>>>>> Perhaps the theory is wrong.
>>>>> Lastly, I would question your assertion that jumbo
>>>> bales are
>>>> "naturally
>>>>> compacted a lot more than the smaller bales."  It is
>>>> mechanically more
>>>>> difficult to compact a larger bale to the same
>>>> density as a smaller
>>>> one.  I
>>>>> am not saying that the machinery isn't designed to do
>>>> so - perhaps it
>>>> is.
>>>>> But, from a pure physics point of view, it is not
>>>> "natural" as you
>>>> said.
>>>>> One way to verify whether the compaction is greater
>>>> or not is to
>>>> measure
>>>>> the water content and density.  Rice straw bales in
>>>> California (the
>>>> ones
>>>> we
>>>>> tested) are typically at least 8 pounds per cubic
>>>> foot at a moisture
>>>>> content of about 6%.  Do you have similar data on the
>>>> Aussie jumbo
>>>> bales?
>>>>> If you want to get an accurate reading of the
>>>> moisture content (more
>>>>> accurate than a moisture meter stuck a random depth
>>>> into the
>>>> bales), let
>>>> me
>>>>> know and I will send you (offline) a description of
>>>> how we did it.
>>>> The
>>>>> density (#/cf or kG/cM) is pretty easy, assuming you
>>>> can weigh a
>>>>> representative sample of the bales.
>>>>> Hope this helps.
>>>>> Thanks,
>>>>>
>>>>> Nehemiah Stone
>>>>> stoneandstraw@...
>>>>
>>>>
>>>> ----
>>>> For instructions on joining, leaving, or otherwise
>>>> using the GSBN list,
>>>> send email to GSBN@...HELP in
>>>> the SUBJECT line.
>>>> ----
>>>>
>>>
>>>
>>>
>>> --
>>> John Swearingen
>>> Skillful Means, Inc.
>>> Design and Construction
>>> www.skillful-means.com
>>>
>>>
>>> --- 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.  ----
>>>
>>>
>>>
>> ----
>> For instructions on joining, leaving, or otherwise using
>> the GSBN list, send email to GSBN@...
>> with 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.
> ----
>



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

Date: 24 May 2007 09:49:00 -0500
From: "Andy Horn" andy@...
Subject: RE:  dipped Bale Walls

Hi all
Just to add my support of the dipping method.

Pre-dipping is for me by far my favourite way of pre-plastering Straw bale,
and have found it helps shave hours and hours off the plastering process,
resulting in a really sturdy solid impregnation of the plaster as well as
helping with the pre-compression/settlement. Furthermore any risk of fire
and weather is hugely reduced as the time that the walls (un-plastered) are
at risk is a matter of an hour or 2 vs. days or weeks! I like it so much
that I have been doing it will all my projects for the last 3 years. 

I first raise the wall for a good fit (allowing for shrinkage in the top
course) and then sequentially take down the walls course by course. I then
dip the bales in a bath of an adobe type clay/sand mix thinned down to a
yogurt like consistency, taking care to only dip the surfaces that are to be
exposed...helping with the weight and in maintaining the insulation. We use
a non load-bearing on-edge system dipping panel by panel. We place the bales
in a bath of "slip" and then turning the bale over, use our hands and a
cobbing stick to really work the slip into the straw, usually achieving at
least 50mm of penetration. We then allow the bales to partially dry out,
until they become more firm and tacky (but not hard)....more like the
consistency of cob. I sometimes call it "cob-bale" building because it is
more like building with giant cob bricks. One sometimes needs to retard the
drying out of the first course/s of bales if there is a lot of wind or
strong sun so as to give oneself enough time to get all the bales dipped. As
the walls go up, we immediately start to work the bales with a cob-stick to
knit the bales together and help compact the coating. As straw falls off in
the bath and makes the bottom too straw rich to dip with, we scoop out this
mix and spread it out to partially dry to a cob like consistency and then
use this as our cob to help fill in any gaps around the base, eaves,
openings etc. I also use a small plank to whack the sides of the bales,
which also helps straighten and compact the coating. Plastering trowels are
also useful for this task. The result is a wall that is really solid, that
when tapped is closer to the feeling of a cob wall, avoiding having that
partly disturbing hollow sound. From there on the subsequent plaster layers
are really easy to do. 

If any of you want to see pictures of the process there are some on our
web-site.

Besides the above advantages mentioned my conviction in the dipping method
has recently hugely re-enforced having this year helped a friend with the
building of 2 load-bearing structures. The builder on site had neglected to
cover up and a huge storm blew in soaking one of the only half roofed
structures. We then had to prop up the roof structure and insert a pole
support system to convert the structure to a non load-bearing building. It
was no fun having to rip out all the mouldy walls that had quickly started
composting.

In such regard, I would be interested to know if any of you have tried the
pre-dipping method with load bearing systems???

Cheers 
Andy Horn 

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
www.ecodesignarchitects.co.za




- -----Original Message-----
From: GSBN [<a  target="_blank" href="mailto:GSBN@...";>mailto:GSBN@...] On Behalf Of Rene Dalmeijer
Sent: 24 May 2007 08:04 AM
To: GSBN
Subject: Re: GSBN:Re Thermal Properties of (french dipped) Straw Bale Walls

Chris,

I fully support you in this it is essential that the dipped bales are 
used quite rapidly after dipping. This is a messy business but working 
with two people to lift and place the bales makes a big difference. The 
bales tend to fit in much better the need for stuffing joints is almost 
diminished to zero.

Another tip once the bales are in place a tamping of the still tacky 
bale surfaces with a plank and a hammer will align and flatten the bale 
surface to a great extent. The best technique is to lay the plank 
across the bale joints and then tamp. To work effectively the clay rich 
slip should still be quite moist.

Rene
On May 24, 2007, at 03:50, cmagwood@...:

> I'd like to kick in on the "French dipped" method, as I
> believe they do a great job of helping to provide a really
> good "seal" across the entire face of the wall. It would
> make sense that if dipped bales are left to dry before
> being stacked that they wouldn't work as well, but they
> shouldn't go in when dried, but when slightly tacky. Then
> the straw/clay that goes in the gaps bonds very well to
> the bales and makes, for me, the best wall surface going.
>
> Chris
>
>>
>> Marty suggested that the 'French dipped' bales might give
>> a good tight
>> fit between the bales. My experience is the opposite. If
>> the bales are
>> dried after being dipped the diped sides get rock hard and
>> do not
>> compress. If the bales are placed before they are dried
>> there is more
>> chance for settling but this is a messier way of going
>> about.
>>
>> As for the test Nehemiah mentioned where the top was
>> stuffed. A
>> suggestions (if such a test is ever to be repeated) is to
>> compress and
>> stuff the wall from below with car jacks between the
>> 'foundation' and
>> botom plate'.
>>
>> Bye,
>>
>> Andre "drop that bale" de Bouter
>>
>>
>>
>> John Swearingen a ecrit :
>>>> Straw-clay seems the best material for this purpose,
>>>> although too
>>>> much clay
>>> might increase conductive heat loss in the stuffed area.
>>> <
>>>
>>> ...for several other reasons, too.  When straw is
>>> stuffed in joints it's
>>> relatively loose and so provides a ready channel for
>>> moisture into the
>>> depths of the wall.  Straw-clay will form a seal against
>>> moisture
>>> entering
>>> the joints between the bales.  In addition, it stops air
>>> infiltration and
>>> can be screeded off to make a flat plain for plaster,
>>> thereby reducing
>>> the
>>> occurance of cracks that result from abrupt changes in
>>> the thickess of
>>> the
>>> plaster.  Also, it's fun to get dirty....
>>>
>>> "Hurlen" John Swearingen
>>>
>>> On 5/19/07, Martin Hammer mfhammer@... wrote:
>>>>
>>>> Nehemiah -
>>>>
>>>> Good explanations.
>>>>
>>>> You talked about the straw-stuffed gaps at the top and
>>>> sides of a
>>>> wall as
>>>> being places where convective losses could occur.  So
>>>> I'll add the
>>>> thermal
>>>> importance of stuffing vertical joints/gaps between
>>>> bales for the same
>>>> reason of limiting convective losses.  (This would also
>>>> be important
>>>> between
>>>> bales and "posts" that go mostly or all the way through
>>>> the thickness of
>>>> the
>>>> wall.  I've seen I-joists or steel trusses used this
>>>> way.)
>>>>
>>>> Straw-clay seems the best material for this purpose,
>>>> although too much
>>>> clay
>>>> might increase conductive heat loss in the stuffed
>>>> area.  Horizontal
>>>> joints
>>>> between bales don't seem to be an issue because the
>>>> weight of the bales
>>>> appear to cause the surfaces to lock in well enough to
>>>> limit air
>>>> movement
>>>> between them (although the French dipped bales might
>>>> seal that joint
>>>> even
>>>> better, and bales on-edge probably nestle together
>>>> better than
>>>> laid-flat).
>>>>
>>>> Then there's always the question of what material is
>>>> between the
>>>> bottom of
>>>> the plates, and what the insulative qualities of the
>>>> roof bearing
>>>> assembly
>>>> are.  And then there's the ceiling/roof, and the
>>>> windows/doors, and the
>>>> amount of infiltration throughout, and . . . . .
>>>>
>>>> Martin Hammer
>>>>
>>>>
>>>>> John,
>>>>>
>>>>> I did not see a response from Andrew.  Was that off
>>>> list?  I am always
>>>>> interested in what new or other information people
>>>> have on the thermal
>>>>> properties of straw bale construction.  Care to share
>>>> his input?
>>>>> Also, your Q about how compaction affects R-value is
>>>> a potent
>>>> question.  If
>>>>> hot box testing wasn't so expensive and time
>>>> consuming, or if there
>>>> were
>>>>> funders lined up to pay for it, I'd already have an
>>>> answer for
>>>> you.  There
>>>>> are a number of confounding factors, so until someone
>>>> has done the
>>>> actual
>>>>> research, we can throw around lots of theories.
>>>>> For example, it is air that creates the insulation
>>>> value of almost
>>>>> everything used for wall insulation.  ,,,not the spun
>>>> glass, not the
>>>> solid
>>>>> portions of the foam, not the cellulose, not the
>>>> straw.
>>>> Therefore, if
>>>>> bales are compacted too much, one would expect the
>>>> insulation value to
>>>> go
>>>>> down.  But, what is "too much?"  If bales are too
>>>> loose, then the air
>>>> can
>>>>> circulate in the air pockets and research HAS shown
>>>> that this can lead
>>>> to
>>>>> convective currents that lead in turn, to a dramatic
>>>> drop in
>>>> R-value.  That
>>>>> was one of the causes (we think) for the relatively
>>>> low R-values in
>>>> the
>>>> ATI
>>>>> lab tests in Fresno, CA.  Once we stacked the bales
>>>> in the hot box
>>>> wall
>>>>> opening, and compressed them as they'd be in a
>>>> building wall, we had a
>>>> six
>>>>> inch gap at the top.  We filled it with straw as
>>>> tightly as we could,
>>>> but
>>>>> we are not match for either a baler or truckers'
>>>> strap tightening
>>>> levers,
>>>>> so we KNOW that the top (where the greatest amount of
>>>> heat exchange
>>>> would
>>>>> naturally occur anyway) was much looser than the rest
>>>> of the
>>>> wall.  Ditto
>>>>> the sides, though those gaps were significantly
>>>> smaller (so perhaps,
>>>> harder
>>>>> to compact straw into).
>>>>> Further, though in theory greater compaction - after
>>>> the optimal
>>>> point -
>>>>> will lead to a decreasing R-value, no tests have yet
>>>> shown that to be
>>>> the
>>>>> case.  Perhaps we just haven't found the optimal
>>>> compression force
>>>> yet.
>>>>> Perhaps the theory is wrong.
>>>>> Lastly, I would question your assertion that jumbo
>>>> bales are
>>>> "naturally
>>>>> compacted a lot more than the smaller bales."  It is
>>>> mechanically more
>>>>> difficult to compact a larger bale to the same
>>>> density as a smaller
>>>> one.  I
>>>>> am not saying that the machinery isn't designed to do
>>>> so - perhaps it
>>>> is.
>>>>> But, from a pure physics point of view, it is not
>>>> "natural" as you
>>>> said.
>>>>> One way to verify whether the compaction is greater
>>>> or not is to
>>>> measure
>>>>> the water content and density.  Rice straw bales in
>>>> California (the
>>>> ones
>>>> we
>>>>> tested) are typically at least 8 pounds per cubic
>>>> foot at a moisture
>>>>> content of about 6%.  Do you have similar data on the
>>>> Aussie jumbo
>>>> bales?
>>>>> If you want to get an accurate reading of the
>>>> moisture content (more
>>>>> accurate than a moisture meter stuck a random depth
>>>> into the
>>>> bales), let
>>>> me
>>>>> know and I will send you (offline) a description of
>>>> how we did it.
>>>> The
>>>>> density (#/cf or kG/cM) is pretty easy, assuming you
>>>> can weigh a
>>>>> representative sample of the bales.
>>>>> Hope this helps.
>>>>> Thanks,
>>>>>
>>>>> Nehemiah Stone
>>>>> stoneandstraw@...
>>>>
>>>>
>>>> ----
>>>> For instructions on joining, leaving, or otherwise
>>>> using the GSBN list,
>>>> send email to GSBN@...HELP in
>>>> the SUBJECT line.
>>>> ----
>>>>
>>>
>>>
>>>
>>> --
>>> John Swearingen
>>> Skillful Means, Inc.
>>> Design and Construction
>>> www.skillful-means.com
>>>
>>>
>>> --- 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.  ----
>>>
>>>
>>>
>> ----
>> For instructions on joining, leaving, or otherwise using
>> the GSBN list, send email to GSBN@...
>> with 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.  
- ----


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

Date: 24 May 2007 11:50:02 -0500
From: stoneandstraw@...
Subject: Re: GSBN:Re Thermal Properties of Straw Bale Walls

Andre said, " As for the test Nehemiah mentioned where the top was stuffed.
A
> suggestions (if such a test is ever to be repeated) is to compress and
> stuff the wall from below with car jacks between the 'foundation' and
> botom plate'."

In an ASTM 236 Hot Box test, you do not have the opportunity/ability to
jack the wall segment up.  You build it upon the insulated (which is
pre-tested for conductivity) base, and you have a set opening size to build
up to - which is why you have to stuff the top once you have compressed the
wall segment.  If you COULD jack the wall up, you would be faced with
almost the same problem (only with jacks or blocks in the way) at the
bottom as we faced at the top.

Nehemiah Stone
stoneandstraw@...



> [Original Message]
> From: Andr#233# de Bouter forum@...
> To: GSBN GSBN@...
> Date: 5/20/2007 3:17:00 AM
> Subject: Re: GSBN:Re Thermal Properties of Straw Bale Walls
>
> An other very effective way to create a snug fit arround the posts was
> shown at the last ISBBC: Put a piece of lumber (that has the dimension
> of your post) on the ground. 'Drop' your bale onto it .Cut of the excess
> straw that sticks out on the side oposite of the piece of lumber. "Et
> voila!"
> This trick only works for bales layed flat and with posts that are
> moderate to small in size. I forgot who showed us this 'gem' during the
> conference.
>
> Marty suggested that the 'French dipped' bales might give a good tight
> fit between the bales. My experience is the opposite. If the bales are
> dried after being dipped the diped sides get rock hard and do not
> compress. If the bales are placed before they are dried there is more
> chance for settling but this is a messier way of going about.
>
> As for the test Nehemiah mentioned where the top was stuffed. A
> suggestions (if such a test is ever to be repeated) is to compress and
> stuff the wall from below with car jacks between the 'foundation' and
> botom plate'.
>
> Bye,
>
> Andr#233# "drop that bale" de Bouter
>
>
>
> John Swearingen a #233#crit :
> >> Straw-clay seems the best material for this purpose, although too
> >> much clay
> > might increase conductive heat loss in the stuffed area. <
> >
> > ...for several other reasons, too.  When straw is stuffed in joints it's
> > relatively loose and so provides a ready channel for moisture into the
> > depths of the wall.  Straw-clay will form a seal against moisture
> > entering
> > the joints between the bales.  In addition, it stops air infiltration
and
> > can be screeded off to make a flat plain for plaster, thereby reducing
> > the
> > occurance of cracks that result from abrupt changes in the thickess of
> > the
> > plaster.  Also, it's fun to get dirty....
> >
> > "Hurlen" John Swearingen
> >
> > On 5/19/07, Martin Hammer mfhammer@... wrote:
> >>
> >> Nehemiah -
> >>
> >> Good explanations.
> >>
> >> You talked about the straw-stuffed gaps at the top and sides of a
> >> wall as
> >> being places where convective losses could occur.  So I'll add the
> >> thermal
> >> importance of stuffing vertical joints/gaps between bales for the same
> >> reason of limiting convective losses.  (This would also be important
> >> between
> >> bales and "posts" that go mostly or all the way through the thickness
of
> >> the
> >> wall.  I've seen I-joists or steel trusses used this way.)
> >>
> >> Straw-clay seems the best material for this purpose, although too much
> >> clay
> >> might increase conductive heat loss in the stuffed area.  Horizontal
> >> joints
> >> between bales don't seem to be an issue because the weight of the bales
> >> appear to cause the surfaces to lock in well enough to limit air
> >> movement
> >> between them (although the French dipped bales might seal that joint
> >> even
> >> better, and bales on-edge probably nestle together better than
> >> laid-flat).
> >>
> >> Then there's always the question of what material is between the
> >> bottom of
> >> the plates, and what the insulative qualities of the roof bearing
> >> assembly
> >> are.  And then there's the ceiling/roof, and the windows/doors, and the
> >> amount of infiltration throughout, and . . . . .
> >>
> >> Martin Hammer
> >>
> >>
> >> > John,
> >> >
> >> > I did not see a response from Andrew.  Was that off list?  I am
always
> >> > interested in what new or other information people have on the
thermal
> >> > properties of straw bale construction.  Care to share his input?
> >> > Also, your Q about how compaction affects R-value is a potent
> >> question.  If
> >> > hot box testing wasn't so expensive and time consuming, or if there
> >> were
> >> > funders lined up to pay for it, I'd already have an answer for
> >> you.  There
> >> > are a number of confounding factors, so until someone has done the
> >> actual
> >> > research, we can throw around lots of theories.
> >> > For example, it is air that creates the insulation value of almost
> >> > everything used for wall insulation.  ,,,not the spun glass, not the
> >> solid
> >> > portions of the foam, not the cellulose, not the straw.
> >> Therefore, if
> >> > bales are compacted too much, one would expect the insulation value
to
> >> go
> >> > down.  But, what is "too much?"  If bales are too loose, then the air
> >> can
> >> > circulate in the air pockets and research HAS shown that this can
lead
> >> to
> >> > convective currents that lead in turn, to a dramatic drop in
> >> R-value.  That
> >> > was one of the causes (we think) for the relatively low R-values in
> >> the
> >> ATI
> >> > lab tests in Fresno, CA.  Once we stacked the bales in the hot box
> >> wall
> >> > opening, and compressed them as they'd be in a building wall, we had
a
> >> six
> >> > inch gap at the top.  We filled it with straw as tightly as we could,
> >> but
> >> > we are not match for either a baler or truckers' strap tightening
> >> levers,
> >> > so we KNOW that the top (where the greatest amount of heat exchange
> >> would
> >> > naturally occur anyway) was much looser than the rest of the
> >> wall.  Ditto
> >> > the sides, though those gaps were significantly smaller (so perhaps,
> >> harder
> >> > to compact straw into).
> >> > Further, though in theory greater compaction - after the optimal
> >> point -
> >> > will lead to a decreasing R-value, no tests have yet shown that to be
> >> the
> >> > case.  Perhaps we just haven't found the optimal compression force
> >> yet.
> >> > Perhaps the theory is wrong.
> >> > Lastly, I would question your assertion that jumbo bales are
> >> "naturally
> >> > compacted a lot more than the smaller bales."  It is mechanically
more
> >> > difficult to compact a larger bale to the same density as a smaller
> >> one.  I
> >> > am not saying that the machinery isn't designed to do so - perhaps it
> >> is.
> >> > But, from a pure physics point of view, it is not "natural" as you
> >> said.
> >> > One way to verify whether the compaction is greater or not is to
> >> measure
> >> > the water content and density.  Rice straw bales in California (the
> >> ones
> >> we
> >> > tested) are typically at least 8 pounds per cubic foot at a moisture
> >> > content of about 6%.  Do you have similar data on the Aussie jumbo
> >> bales?
> >> > If you want to get an accurate reading of the moisture content (more
> >> > accurate than a moisture meter stuck a random depth into the
> >> bales), let
> >> me
> >> > know and I will send you (offline) a description of how we did it.
> >> The
> >> > density (#/cf or kG/cM) is pretty easy, assuming you can weigh a
> >> > representative sample of the bales.
> >> > Hope this helps.
> >> > Thanks,
> >> >
> >> > Nehemiah Stone
> >> > stoneandstraw@...
> >>
> >>
> >> ----
> >> For instructions on joining, leaving, or otherwise using the GSBN list,
> >> send email to GSBN@...HELP in the SUBJECT
line.
> >> ----
> >>
> >
> >
> >
> > --
> > John Swearingen
> > Skillful Means, Inc.
> > Design and Construction
> > www.skillful-means.com
> >
> >
> > --- 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: 24 May 2007 11:52:48 -0500
From: stoneandstraw@...
Subject: Re: GSBN:Re Thermal Properties of Straw Bale Walls

John,

You are right.  ...for actual buildings.  Still, for a test, load bearing
does not solve the problem.  The wall segments tested WERE load bearing.
The problem is that you need a tight fit between the edges (top, bottom,
and sides) of the wall segment and your surround panels of known
conductivity.  Otherwise, you get less insulative areas that screw up the
"average" conductivity results.

Nehemiah Stone
stoneandstraw@...



> [Original Message]
> From: John Glassford jacksflat@...
> To: GSBN GSBN@...
> Date: 5/20/2007 10:16:39 AM
> Subject: Re: GSBN:Re Thermal Properties of Straw Bale Walls
>
> G ' day
>
> You can avoid all the chain sawing, squishing and car jacking and
> stuffing by going load bearing.
><snip>




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

Date: 24 May 2007 12:27:59 -0500
From: Bob Theis bob@...
Subject: Re: GSBN:Re Thermal Properties of Straw Bale Walls

Nehemiah,

Here's a thought for the next (?) test:

Stack and finish a wall larger than the test panel, then chain saw
out a segment that fits. This creates the challenge of getting it
into the frame, but you get a more "average" wall.

Bob Theis


On May 24, 2007, at 10:45 AM, Nehemiah Stone wrote:

> John,
>
> You are right.  ...for actual buildings.  Still, for a test, load
> bearing
> does not solve the problem.  The wall segments tested WERE load
> bearing.
> The problem is that you need a tight fit between the edges (top,
> bottom,
> and sides) of the wall segment and your surround panels of known
> conductivity.  Otherwise, you get less insulative areas that screw
> up the
> "average" conductivity results.
>
> Nehemiah Stone
> stoneandstraw@...
>
>
>
>> [Original Message]
>> From: John Glassford jacksflat@...
>> To: GSBN GSBN@...
>> Date: 5/20/2007 10:16:39 AM
>> Subject: Re: GSBN:Re Thermal Properties of Straw Bale Walls
>>
>> G ' day
>>
>> You can avoid all the chain sawing, squishing and car jacking and
>> stuffing by going load bearing.
>> <snip>
>
>

>



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

Date: 24 May 2007 12:48:19 -0500
From: Martin Hammer mfhammer@...
Subject: Re: GSBN:Colombia

Hello Andre, and Bill Christensen,

Darrel DeBoer (architect in California) I know has something to say about
this subject.  He has done much work with bamboo in Colombia, and has done
much work with straw bale in California.  Bruce King and I nominated him
back in February, and I thought that he had been accepted and added to the
GSbN list.  I just spoke with him, and apparently not.  Is this just an
oversight?

He wants very much to participate, and can add much to the informed,
informative, inquisitive, erudite, incisive, amusing, sometimes fiesty,
sometimes rambling (like what I'm doing now), often profound dialogue that
is the GSBN.

His e-mail is:  Darrel@...

Thanks.

Martin Hammer




> Hello,
> 
> One of my workshop participants is Colombian and plans on going back to
> his homeland. (He also has some contacts with a university there).
> He would like to know if any SB building is happening there and, if so,
> he'd like some contact information. Anyone?
> 
> Bye,
> Andre
> ----
> For instructions on joining, leaving, or otherwise using the GSBN list, send
> email to GSBN@...HELP in the SUBJECT line.
> ----
> 




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

Date: 24 May 2007 13:05:45 -0500
From: Catherine Wanek cat@...
Subject: Re: GSBN:Colombia

I also support Darrel Deboer's nomination.  Ditto what Martin Hammer said.
- -Catherine

Darrel DeBoer (architect in California) I know has something to say about
>this subject.  He has done much work with bamboo in Colombia, and has done
>much work with straw bale in California.  ..........He wants very
>much to participate
>His e-mail is:  Darrel@...
>
>Thanks.  Martin Hammer


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

Date: 24 May 2007 13:33:31 -0500
From: Bruce King ecobruce@...
Subject: Re: Darrel Deboer's nomination


On May 24, 2007, at 11:52 AM, Catherine Wanek wrote:

> I also support Darrel Deboer's nomination.  Ditto what Martin Hammer
> said.

ditto again.  I thought Darrel was already here.

Thanks,

Bruce King, PE
Director, Ecological Building Network  ( www.ecobuildnetwork.org )
Publisher, Green Building Press  ( www.greenbuildingpress.com )
11 Mark Drive
San Rafael, CA 94903  USA
(415) 987-7271
bruce@ ecobuildnetwork.org


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

Date: 24 May 2007 15:18:38 -0500
From: "Andre_de_Bouter" forum@...
Subject: Re: GSBN:Re Thermal Properties of Straw Bale Walls

Dear Nehemiah,

Apparently I did not get across what I intended to say. But it's not
that important.

As for stuffing the top of a post and beam structure, this is how I do
it (and I'm convinced  it is almost as dense as the rest of the wall) :
First place your bales to form your wall (* keep in mind that in France
the bales are usually placed on on top of one another, squished between
planks of 4x20 cm (2x4 inch))
When we get to the last row that can be placed we do NOT place them.
Instead we place a thick plank which we push down with a carjack. This
pushes down the bales, eliminating any (horizontal) voids between the
bales and making the wall a whole lot sturdier. We then prepare the
custom bales that will fill the space between the last bales posed and
the ring beam. To avoid stuffing with flakes (this is my main point) we
place those custom bales vertically thus filling the space of the last
row of bales + the space above it (and you bet you your bottom dollar
that MY custom bales are as dense as any bale coming straight out of a
baler ;-). When the custom bales are ready we take out the jack (the
bales bounce up a bit) and place the bales. We use 'shoe horns' made of
sheet metal to make sure the bales slide in as tight as possible without
the need to force a lot (I hope the word 'shoe horn' is correct, what I
mean is the metal object one uses to get in those very tight dancing
shoes). By the way the sheet metal is folded on one end so that it is
easily pulled out again. The bales will come up even more and this
creates an even pressure throughout the wall (at least we think so).

* car jacking a whole wall down is obviously tricky, but for a test
panel this should not be that difficult.

This said, I also like Bob's idea to cut out a piece of a larger wall.
But cutting would need to be accurate and handling could be difficult.
And I agree with wolfman that eliminating the the post and beam
structure using big bales is a very interesting way to go (but one would
need a crane to dip them ;-)

Bye,

Stuffed up Andre

PS thanks Martin for Darrel DeBoer's email.




Nehemiah Stone a ecrit :
> Andre said, " As for the test Nehemiah mentioned where the top was stuffed.
> A
>
>> suggestions (if such a test is ever to be repeated) is to compress and
>> stuff the wall from below with car jacks between the 'foundation' and
>> botom plate'."
>>
>
> In an ASTM 236 Hot Box test, you do not have the opportunity/ability to
> jack the wall segment up.  You build it upon the insulated (which is
> pre-tested for conductivity) base, and you have a set opening size to build
> up to - which is why you have to stuff the top once you have compressed the
> wall segment.  If you COULD jack the wall up, you would be faced with
> almost the same problem (only with jacks or blocks in the way) at the
> bottom as we faced at the top.
>
> Nehemiah Stone
> stoneandstraw@...
>
>
>
>
>> [Original Message]
>> From: Andre de Bouter forum@...
>> To: GSBN GSBN@...
>> Date: 5/20/2007 3:17:00 AM
>> Subject: Re: GSBN:Re Thermal Properties of Straw Bale Walls
>>
>> An other very effective way to create a snug fit arround the posts was
>> shown at the last ISBBC: Put a piece of lumber (that has the dimension
>> of your post) on the ground. 'Drop' your bale onto it .Cut of the excess
>> straw that sticks out on the side oposite of the piece of lumber. "Et
>> voila!"
>> This trick only works for bales layed flat and with posts that are
>> moderate to small in size. I forgot who showed us this 'gem' during the
>> conference.
>>
>> Marty suggested that the 'French dipped' bales might give a good tight
>> fit between the bales. My experience is the opposite. If the bales are
>> dried after being dipped the diped sides get rock hard and do not
>> compress. If the bales are placed before they are dried there is more
>> chance for settling but this is a messier way of going about.
>>
>> As for the test Nehemiah mentioned where the top was stuffed. A
>> suggestions (if such a test is ever to be repeated) is to compress and
>> stuff the wall from below with car jacks between the 'foundation' and
>> botom plate'.
>>
>> Bye,
>>
>> Andre "drop that bale" de Bouter
>>
>>
>>
>> John Swearingen a ecrit :
>>
>>>> Straw-clay seems the best material for this purpose, although too
>>>> much clay
>>>>
>>> might increase conductive heat loss in the stuffed area. <
>>>
>>> ...for several other reasons, too.  When straw is stuffed in joints it's
>>> relatively loose and so provides a ready channel for moisture into the
>>> depths of the wall.  Straw-clay will form a seal against moisture
>>> entering
>>> the joints between the bales.  In addition, it stops air infiltration
>>>
> and
>
>>> can be screeded off to make a flat plain for plaster, thereby reducing
>>> the
>>> occurance of cracks that result from abrupt changes in the thickess of
>>> the
>>> plaster.  Also, it's fun to get dirty....
>>>
>>> "Hurlen" John Swearingen
>>>
>>> On 5/19/07, Martin Hammer mfhammer@... wrote:
>>>
>>>> Nehemiah -
>>>>
>>>> Good explanations.
>>>>
>>>> You talked about the straw-stuffed gaps at the top and sides of a
>>>> wall as
>>>> being places where convective losses could occur.  So I'll add the
>>>> thermal
>>>> importance of stuffing vertical joints/gaps between bales for the same
>>>> reason of limiting convective losses.  (This would also be important
>>>> between
>>>> bales and "posts" that go mostly or all the way through the thickness
>>>>
> of
>
>>>> the
>>>> wall.  I've seen I-joists or steel trusses used this way.)
>>>>
>>>> Straw-clay seems the best material for this purpose, although too much
>>>> clay
>>>> might increase conductive heat loss in the stuffed area.  Horizontal
>>>> joints
>>>> between bales don't seem to be an issue because the weight of the bales
>>>> appear to cause the surfaces to lock in well enough to limit air
>>>> movement
>>>> between them (although the French dipped bales might seal that joint
>>>> even
>>>> better, and bales on-edge probably nestle together better than
>>>> laid-flat).
>>>>
>>>> Then there's always the question of what material is between the
>>>> bottom of
>>>> the plates, and what the insulative qualities of the roof bearing
>>>> assembly
>>>> are.  And then there's the ceiling/roof, and the windows/doors, and the
>>>> amount of infiltration throughout, and . . . . .
>>>>
>>>> Martin Hammer
>>>>
>>>>
>>>>
>>>>> John,
>>>>>
>>>>> I did not see a response from Andrew.  Was that off list?  I am
>>>>>
> always
>
>>>>> interested in what new or other information people have on the
>>>>>
> thermal
>
>>>>> properties of straw bale construction.  Care to share his input?
>>>>> Also, your Q about how compaction affects R-value is a potent
>>>>>
>>>> question.  If
>>>>
>>>>> hot box testing wasn't so expensive and time consuming, or if there
>>>>>
>>>> were
>>>>
>>>>> funders lined up to pay for it, I'd already have an answer for
>>>>>
>>>> you.  There
>>>>
>>>>> are a number of confounding factors, so until someone has done the
>>>>>
>>>> actual
>>>>
>>>>> research, we can throw around lots of theories.
>>>>> For example, it is air that creates the insulation value of almost
>>>>> everything used for wall insulation.  ,,,not the spun glass, not the
>>>>>
>>>> solid
>>>>
>>>>> portions of the foam, not the cellulose, not the straw.
>>>>>
>>>> Therefore, if
>>>>
>>>>> bales are compacted too much, one would expect the insulation value
>>>>>
> to
>
>>>> go
>>>>
>>>>> down.  But, what is "too much?"  If bales are too loose, then the air
>>>>>
>>>> can
>>>>
>>>>> circulate in the air pockets and research HAS shown that this can
>>>>>
> lead
>
>>>> to
>>>>
>>>>> convective currents that lead in turn, to a dramatic drop in
>>>>>
>>>> R-value.  That
>>>>
>>>>> was one of the causes (we think) for the relatively low R-values in
>>>>>
>>>> the
>>>> ATI
>>>>
>>>>> lab tests in Fresno, CA.  Once we stacked the bales in the hot box
>>>>>
>>>> wall
>>>>
>>>>> opening, and compressed them as they'd be in a building wall, we had
>>>>>
> a
>
>>>> six
>>>>
>>>>> inch gap at the top.  We filled it with straw as tightly as we could,
>>>>>
>>>> but
>>>>
>>>>> we are not match for either a baler or truckers' strap tightening
>>>>>
>>>> levers,
>>>>
>>>>> so we KNOW that the top (where the greatest amount of heat exchange
>>>>>
>>>> would
>>>>
>>>>> naturally occur anyway) was much looser than the rest of the
>>>>>
>>>> wall.  Ditto
>>>>
>>>>> the sides, though those gaps were significantly smaller (so perhaps,
>>>>>
>>>> harder
>>>>
>>>>> to compact straw into).
>>>>> Further, though in theory greater compaction - after the optimal
>>>>>
>>>> point -
>>>>
>>>>> will lead to a decreasing R-value, no tests have yet shown that to be
>>>>>
>>>> the
>>>>
>>>>> case.  Perhaps we just haven't found the optimal compression force
>>>>>
>>>> yet.
>>>>
>>>>> Perhaps the theory is wrong.
>>>>> Lastly, I would question your assertion that jumbo bales are
>>>>>
>>>> "naturally
>>>>
>>>>> compacted a lot more than the smaller bales."  It is mechanically
>>>>>
> more
>
>>>>> difficult to compact a larger bale to the same density as a smaller
>>>>>
>>>> one.  I
>>>>
>>>>> am not saying that the machinery isn't designed to do so - perhaps it
>>>>>
>>>> is.
>>>>
>>>>> But, from a pure physics point of view, it is not "natural" as you
>>>>>
>>>> said.
>>>>
>>>>> One way to verify whether the compaction is greater or not is to
>>>>>
>>>> measure
>>>>
>>>>> the water content and density.  Rice straw bales in California (the
>>>>>
>>>> ones
>>>> we
>>>>
>>>>> tested) are typically at least 8 pounds per cubic foot at a moisture
>>>>> content of about 6%.  Do you have similar data on the Aussie jumbo
>>>>>
>>>> bales?
>>>>
>>>>> If you want to get an accurate reading of the moisture content (more
>>>>> accurate than a moisture meter stuck a random depth into the
>>>>>
>>>> bales), let
>>>> me
>>>>
>>>>> know and I will send you (offline) a description of how we did it.
>>>>>
>>>> The
>>>>
>>>>> density (#/cf or kG/cM) is pretty easy, assuming you can weigh a
>>>>> representative sample of the bales.
>>>>> Hope this helps.
>>>>> Thanks,
>>>>>
>>>>> Nehemiah Stone
>>>>> stoneandstraw@...
>>>>>
>>>> ----
>>>> For instructions on joining, leaving, or otherwise using the GSBN list,
>>>> send email to GSBN@...HELP in the SUBJECT
>>>>
> line.
>
>>>> ----
>>>>
>>>>
>>>
>>> --
>>> John Swearingen
>>> Skillful Means, Inc.
>>> Design and Construction
>>> www.skillful-means.com
>>>
>>>
>>> --- 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.  ----
>>>
>>>
>>>
>>>
>> ----
>> 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.
> ----
>
>
>
>


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

Date: 24 May 2007 16:21:44 -0500
From: john@...
Subject: Re: GSBN:Re Thermal Properties of Straw Bale Walls

G ' day Andre

Not easy dipping zee jumbo bales mate.

I like the concept of dipping bales but it is not very practical even
with small bales IMO.

We prefer to build them in the raw and do a solid pre-compression and
then fill any gaps with a cob mix.

Here is a students view of one of our workshops:

<a  target="_blank" href="http://homepage.mac.com/rhferguson1/PhotoAlbum6.html";>http://homepage.mac.com/rhferguson1/PhotoAlbum6.html</a>

Getting back to load bearing jumbo bales we make sure that the bales
have good straight ends which we make even straighter with a chain saw
or brush cutter.  This way there are few if any gaps to fill in a
wall.

See the house on the South Coast with very sharp corners using small bales:

<a  target="_blank" href="http://www.glassford.com.au/South%20Coast%20NSW.htm";>http://www.glassford.com.au/South%20Coast%20NSW.htm</a>

We achieved excellent pre-compression and with good bales zero holes
to fill in even though it is an in-fill.
- --
Kind regards
El Lupo
Huff 'n' Puff Constructions
<a  target="_blank" href="http://www.glassford.com.au/";>http://www.glassford.com.au/</a>
Mount Kilimanjaro Climb 28/8/07
<a  target="_blank" href="http://www.coolamonrotary.com/kili/";>http://www.coolamonrotary.com/kili/</a>
61 2 6927 6027


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

Date: 24 May 2007 17:58:00 -0500
From: stoneandstraw@...
Subject: Re: GSBN:Re Thermal Properties of Straw Bale Walls

Andre,

Thanks.  You're right, I completely misunderstood.  We actually could
possibly have done something essentially like that.  The way the Straw Dogs
(Turko Semmes and Greg McMillam, who helped on the project) did compression
in those days (1996), they used airline strapping and levered, ratcheted
tightening tools - not too dissimilar in design from the chain tighteners
that long haul truckers ("lorry drivers") used to tighten the chains across
their loads.  We Could, I suppose, have custom-cut a row of bales so that
once compressed, the rest of the wall (all but the tip row) left just
enough room to insert one last row.  ...then we could have released some of
the tension on the rest of the wall to tighten up the top row.  If I am
ever involved in testing a bale wall in a hot box again, I think I will try
that method.  Thanks!

Nehemiah Stone
stoneandstraw@...



> [Original Message]
> From: Andr#233# de Bouter forum@...
> To: GSBN GSBN@...
> Date: 5/24/2007 2:08:50 PM
> Subject: Re: GSBN:Re Thermal Properties of Straw Bale Walls
>
> Dear Nehemiah,
>
> Apparently I did not get across what I intended to say. But it's not
> that important.
>
> As for stuffing the top of a post and beam structure, this is how I do
> it (and I'm convinced  it is almost as dense as the rest of the wall) :
> First place your bales to form your wall (* keep in mind that in France
> the bales are usually placed on on top of one another, squished between
> planks of 4x20 cm (2x4 inch))
> When we get to the last row that can be placed we do NOT place them.
> Instead we place a thick plank which we push down with a carjack. This
> pushes down the bales, eliminating any (horizontal) voids between the
> bales and making the wall a whole lot sturdier. We then prepare the
> custom bales that will fill the space between the last bales posed and
> the ring beam. To avoid stuffing with flakes (this is my main point) we
> place those custom bales vertically thus filling the space of the last
> row of bales + the space above it (and you bet you your bottom dollar
> that MY custom bales are as dense as any bale coming straight out of a
> baler ;-). When the custom bales are ready we take out the jack (the
> bales bounce up a bit) and place the bales. We use 'shoe horns' made of
> sheet metal to make sure the bales slide in as tight as possible without
> the need to force a lot (I hope the word 'shoe horn' is correct, what I
> mean is the metal object one uses to get in those very tight dancing
> shoes). By the way the sheet metal is folded on one end so that it is
> easily pulled out again. The bales will come up even more and this
> creates an even pressure throughout the wall (at least we think so).
>
> * car jacking a whole wall down is obviously tricky, but for a test
> panel this should not be that difficult.
>
> This said, I also like Bob's idea to cut out a piece of a larger wall.
> But cutting would need to be accurate and handling could be difficult.
> And I agree with wolfman that eliminating the the post and beam
> structure using big bales is a very interesting way to go (but one would
> need a crane to dip them ;-)
>
> Bye,
>
> Stuffed up Andr#233#
>
> PS thanks Martin for Darrel DeBoer's email.
>
>
>
>
> Nehemiah Stone a #233#crit :
> > Andre said, " As for the test Nehemiah mentioned where the top was
stuffed.
> > A
> >
> >> suggestions (if such a test is ever to be repeated) is to compress and
> >> stuff the wall from below with car jacks between the 'foundation' and
> >> botom plate'."
> >>
> >
> > In an ASTM 236 Hot Box test, you do not have the opportunity/ability to
> > jack the wall segment up.  You build it upon the insulated (which is
> > pre-tested for conductivity) base, and you have a set opening size to
build
> > up to - which is why you have to stuff the top once you have compressed
the
> > wall segment.  If you COULD jack the wall up, you would be faced with
> > almost the same problem (only with jacks or blocks in the way) at the
> > bottom as we faced at the top.
> >
> > Nehemiah Stone
> > stoneandstraw@...
> >
> >
> >
> >
> >> [Original Message]
> >> From: Andr#233# de Bouter forum@...
> >> To: GSBN GSBN@...
> >> Date: 5/20/2007 3:17:00 AM
> >> Subject: Re: GSBN:Re Thermal Properties of Straw Bale Walls
> >>
> >> An other very effective way to create a snug fit arround the posts was
> >> shown at the last ISBBC: Put a piece of lumber (that has the dimension
> >> of your post) on the ground. 'Drop' your bale onto it .Cut of the
excess
> >> straw that sticks out on the side oposite of the piece of lumber. "Et
> >> voila!"
> >> This trick only works for bales layed flat and with posts that are
> >> moderate to small in size. I forgot who showed us this 'gem' during the
> >> conference.
> >>
> >> Marty suggested that the 'French dipped' bales might give a good tight
> >> fit between the bales. My experience is the opposite. If the bales are
> >> dried after being dipped the diped sides get rock hard and do not
> >> compress. If the bales are placed before they are dried there is more
> >> chance for settling but this is a messier way of going about.
> >>
> >> As for the test Nehemiah mentioned where the top was stuffed. A
> >> suggestions (if such a test is ever to be repeated) is to compress and
> >> stuff the wall from below with car jacks between the 'foundation' and
> >> botom plate'.
> >>
> >> Bye,
> >>
> >> Andr#233# "drop that bale" de Bouter
> >>
> >>
> >>
> >> John Swearingen a #233#crit :
> >>
> >>>> Straw-clay seems the best material for this purpose, although too
> >>>> much clay
> >>>>
> >>> might increase conductive heat loss in the stuffed area. <
> >>>
> >>> ...for several other reasons, too.  When straw is stuffed in joints
it's
> >>> relatively loose and so provides a ready channel for moisture into the
> >>> depths of the wall.  Straw-clay will form a seal against moisture
> >>> entering
> >>> the joints between the bales.  In addition, it stops air infiltration
> >>>
> > and
> >
> >>> can be screeded off to make a flat plain for plaster, thereby reducing
> >>> the
> >>> occurance of cracks that result from abrupt changes in the thickess of
> >>> the
> >>> plaster.  Also, it's fun to get dirty....
> >>>
> >>> "Hurlen" John Swearingen
> >>>
> >>> On 5/19/07, Martin Hammer mfhammer@... wrote:
> >>>
> >>>> Nehemiah -
> >>>>
> >>>> Good explanations.
> >>>>
> >>>> You talked about the straw-stuffed gaps at the top and sides of a
> >>>> wall as
> >>>> being places where convective losses could occur.  So I'll add the
> >>>> thermal
> >>>> importance of stuffing vertical joints/gaps between bales for the
same
> >>>> reason of limiting convective losses.  (This would also be important
> >>>> between
> >>>> bales and "posts" that go mostly or all the way through the thickness
> >>>>
> > of
> >
> >>>> the
> >>>> wall.  I've seen I-joists or steel trusses used this way.)
> >>>>
> >>>> Straw-clay seems the best material for this purpose, although too
much
> >>>> clay
> >>>> might increase conductive heat loss in the stuffed area.  Horizontal
> >>>> joints
> >>>> between bales don't seem to be an issue because the weight of the
bales
> >>>> appear to cause the surfaces to lock in well enough to limit air
> >>>> movement
> >>>> between them (although the French dipped bales might seal that joint
> >>>> even
> >>>> better, and bales on-edge probably nestle together better than
> >>>> laid-flat).
> >>>>
> >>>> Then there's always the question of what material is between the
> >>>> bottom of
> >>>> the plates, and what the insulative qualities of the roof bearing
> >>>> assembly
> >>>> are.  And then there's the ceiling/roof, and the windows/doors, and
the
> >>>> amount of infiltration throughout, and . . . . .
> >>>>
> >>>> Martin Hammer
> >>>>
> >>>>
> >>>>
> >>>>> John,
> >>>>>
> >>>>> I did not see a response from Andrew.  Was that off list?  I am
> >>>>>
> > always
> >
> >>>>> interested in what new or other information people have on the
> >>>>>
> > thermal
> >
> >>>>> properties of straw bale construction.  Care to share his input?
> >>>>> Also, your Q about how compaction affects R-value is a potent
> >>>>>
> >>>> question.  If
> >>>>
> >>>>> hot box testing wasn't so expensive and time consuming, or if there
> >>>>>
> >>>> were
> >>>>
> >>>>> funders lined up to pay for it, I'd already have an answer for
> >>>>>
> >>>> you.  There
> >>>>
> >>>>> are a number of confounding factors, so until someone has done the
> >>>>>
> >>>> actual
> >>>>
> >>>>> research, we can throw around lots of theories.
> >>>>> For example, it is air that creates the insulation value of almost
> >>>>> everything used for wall insulation.  ,,,not the spun glass, not the
> >>>>>
> >>>> solid
> >>>>
> >>>>> portions of the foam, not the cellulose, not the straw.
> >>>>>
> >>>> Therefore, if
> >>>>
> >>>>> bales are compacted too much, one would expect the insulation value
> >>>>>
> > to
> >
> >>>> go
> >>>>
> >>>>> down.  But, what is "too much?"  If bales are too loose, then the
air
> >>>>>
> >>>> can
> >>>>
> >>>>> circulate in the air pockets and research HAS shown that this can
> >>>>>
> > lead
> >
> >>>> to
> >>>>
> >>>>> convective currents that lead in turn, to a dramatic drop in
> >>>>>
> >>>> R-value.  That
> >>>>
> >>>>> was one of the causes (we think) for the relatively low R-values in
> >>>>>
> >>>> the
> >>>> ATI
> >>>>
> >>>>> lab tests in Fresno, CA.  Once we stacked the bales in the hot box
> >>>>>
> >>>> wall
> >>>>
> >>>>> opening, and compressed them as they'd be in a building wall, we had
> >>>>>
> > a
> >
> >>>> six
> >>>>
> >>>>> inch gap at the top.  We filled it with straw as tightly as we
could,
> >>>>>
> >>>> but
> >>>>
> >>>>> we are not match for either a baler or truckers' strap tightening
> >>>>>
> >>>> levers,
> >>>>
> >>>>> so we KNOW that the top (where the greatest amount of heat exchange
> >>>>>
> >>>> would
> >>>>
> >>>>> naturally occur anyway) was much looser than the rest of the
> >>>>>
> >>>> wall.  Ditto
> >>>>
> >>>>> the sides, though those gaps were significantly smaller (so perhaps,
> >>>>>
> >>>> harder
> >>>>
> >>>>> to compact straw into).
> >>>>> Further, though in theory greater compaction - after the optimal
> >>>>>
> >>>> point -
> >>>>
> >>>>> will lead to a decreasing R-value, no tests have yet shown that to
be
> >>>>>
> >>>> the
> >>>>
> >>>>> case.  Perhaps we just haven't found the optimal compression force
> >>>>>
> >>>> yet.
> >>>>
> >>>>> Perhaps the theory is wrong.
> >>>>> Lastly, I would question your assertion that jumbo bales are
> >>>>>
> >>>> "naturally
> >>>>
> >>>>> compacted a lot more than the smaller bales."  It is mechanically
> >>>>>
> > more
> >
> >>>>> difficult to compact a larger bale to the same density as a smaller
> >>>>>
> >>>> one.  I
> >>>>
> >>>>> am not saying that the machinery isn't designed to do so - perhaps
it
> >>>>>
> >>>> is.
> >>>>
> >>>>> But, from a pure physics point of view, it is not "natural" as you
> >>>>>
> >>>> said.
> >>>>
> >>>>> One way to verify whether the compaction is greater or not is to
> >>>>>
> >>>> measure
> >>>>
> >>>>> the water content and density.  Rice straw bales in California (the
> >>>>>
> >>>> ones
> >>>> we
> >>>>
> >>>>> tested) are typically at least 8 pounds per cubic foot at a moisture
> >>>>> content of about 6%.  Do you have similar data on the Aussie jumbo
> >>>>>
> >>>> bales?
> >>>>
> >>>>> If you want to get an accurate reading of the moisture content (more
> >>>>> accurate than a moisture meter stuck a random depth into the
> >>>>>
> >>>> bales), let
> >>>> me
> >>>>
> >>>>> know and I will send you (offline) a description of how we did it.
> >>>>>
> >>>> The
> >>>>
> >>>>> density (#/cf or kG/cM) is pretty easy, assuming you can weigh a
> >>>>> representative sample of the bales.
> >>>>> Hope this helps.
> >>>>> Thanks,
> >>>>>
> >>>>> Nehemiah Stone
> >>>>> stoneandstraw@...
> >>>>>
> >>>> ----
> >>>> For instructions on joining, leaving, or otherwise using the GSBN
list,
> >>>> send email to GSBN@...HELP in the SUBJECT
> >>>>
> > line.
> >
> >>>> ----
> >>>>
> >>>>
> >>>
> >>> --
> >>> John Swearingen
> >>> Skillful Means, Inc.
> >>> Design and Construction
> >>> www.skillful-means.com
> >>>
> >>>
> >>> --- 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.  ----
> >>>
> >>>
> >>>
> >>>
> >> ----
> >> 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.
> > ----
> >
> >
> >
> >

>




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

Date: 24 May 2007 19:33:18 -0500
From: billc billc_lists@...
Subject: Re: GSBN:Colombia

At 11:36 AM -0700 5/24/07, Martin Hammer wrote:
>Hello Andre, and Bill Christensen,
>
>Darrel DeBoer (architect in California) I know has something to say about
>this subject.  He has done much work with bamboo in Colombia, and has done
>much work with straw bale in California.  Bruce King and I nominated him
>back in February, and I thought that he had been accepted and added to the
>GSbN list.  I just spoke with him, and apparently not.  Is this just an
>oversight?
>
>He wants very much to participate, and can add much to the informed,
>informative, inquisitive, erudite, incisive, amusing, sometimes fiesty,
>sometimes rambling (like what I'm doing now), often profound dialogue that
>is the GSBN.
>
>His e-mail is:  Darrel@...


Hi folks.

I just added Darrel to GSBN.  I thought that he was on for a few
months and then asked to be taken off, but I may be thinking of
someone else.


- --
Bill Christensen
billc@...

Green Building Professionals Directory: <<a  target="_blank" href="http://directory.sustainablesources.com";>http://directory.sustainablesources.com</a>>
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----------------------------------------------------------------------

Date: 24 May 2007 20:03:30 -0500
From: billc billc_lists@...
Subject: Re: GSBN:Re Thermal Properties of Straw Bale Walls

At 8:08 AM +1000 5/25/07, John Glassford wrote:
>
>We prefer to build them in the raw and do a solid pre-compression and
>then fill any gaps with a cob mix.

Since it can be difficult to do gap-filling in the first place, would
it make better sense to stuff and *then* compress, allowing the straw
to mold into the cob?


- --
Bill Christensen
billc@...

Green Building Professionals Directory: <<a  target="_blank" href="http://directory.sustainablesources.com";>http://directory.sustainablesources.com</a>>
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----------------------------------------------------------------------

Date: 24 May 2007 20:24:20 -0500
From: john@...
Subject: Re: GSBN:Re Thermal Properties of Straw Bale Walls

Good idea Bill and in effect that what happens but with good
preparation of each bale and good bales in the first place this is not
such a problem gaps that is.  Also the pre-compression using all
thread as per Steens or the hybrid method seen here is the way to go:

<a  target="_blank" href="http://www.glassford.com.au/Custom_meredith.htm";>http://www.glassford.com.au/Custom_meredith.htm</a>

The rods on each side of the wall every 1.8 metres work a treat and
are much easer and stronger than any other method that I have used
including fencing wire, gripples and straps of all types.

Just my two bobs worth mate.

Kind regards
El Lupo
Huff 'n' Puff Constructions
<a  target="_blank" href="http://www.glassford.com.au/";>http://www.glassford.com.au/</a>
Mount Kilimanjaro Climb 28/8/07
<a  target="_blank" href="http://www.coolamonrotary.com/kili/";>http://www.coolamonrotary.com/kili/</a>
61 2 6927 6027


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

Date: 24 May 2007 20:58:40 -0500
From: Joy Bennett mbenn1035@...
Subject: Darrell DeBoer

A hearty second to DeBoer's nomination - a good
addition.  Like Bruce I had thought he was already on
the list.

Maurice Bennett

Maurice and Joy Bennett


You must be the change you want to see in the world.   Gandhi



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