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Today's Topics:
1. Strawbale position (Sport Hotel, Jure Pozar)
2. Re: Strawbale position (Andrew Morrison)
3. www.strawbale-net.eu LAUNCHED! (nora kasanicka)
4. Re: Strawbale position (Derek Roff)
----------------------------------------------------------------------
Message: 1
Date: Tue, 12 Oct 2010 12:57:05 +0200
From: "Sport Hotel, Jure Pozar" <jure.pozar@gmail...>
Subject: [Strawbale] Strawbale position
To: European strawbale building discussions
<strawbale@amper....muni.cz>
Message-ID: <4CB43F01.10801@gmail...>
Content-Type: text/plain; charset="iso-8859-1"
Dear all,
I am in the phase of designing our straw bale house and I have heard
that if you lay the straw bale horizontaly it has the same isolation
conductivity as if laid vertical. Lets presume the bales? dimension is
45 x 35 x 100 cm which would mean that laid horizontaly the strawbale
wall would be 45 cm and verticaly would be 35 cm (the isolation at
this
second option is supposed to be better due to straws which are in
vertical position). Does anybody know of tests performed and published
of this particulat subject. If this is true you need much less
strawbales to built your house. I am of course talking about post &
beam
method. Probably this would present a problem at loadbearing method.
Does anybody know of any difficulties when building post & beam and
bales put vertical?
I would appreciate any answer
Regards,
Jure Poz(ar
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Message: 2
Date: Tue, 12 Oct 2010 07:16:54 -0700
From: Andrew Morrison <Andrew@StrawBale...>
Subject: Re: [Strawbale] Strawbale position
To: European strawbale building discussions
<strawbale@amper....muni.cz>, Jure Pozar <jure.pozar@gmail...>
Message-ID:
<AANLkTinD0tOiQUhJcnJ_RE_j3DQkDMiV4ChR7L9t7pFc@mail....com>
Content-Type: text/plain; charset="utf-8"
Hello Jure. There are some studies out there about the insulation
value of
straw bales stacked horizontally (on the flat) and vertically (on
edge);
however, I do not think that any of them are terribly accurate. In
each,
there are details that are subjective. I do believe that they all
conclude
that the straw orientation does indeed affect the insulation value
of the
bales, thus making bales stacked on edge higher R-value per inch
than bales
stacked horizontally. This effectively gives you the same R-value
for the
bales stacked either way, simply allowing you to use less space in
your home
for the actual wall thickness. That said, many new baling machines are
orienting the straw differently, or not at all (chopped straw from
combines
for example is so small that the straw orientation is every which
way).
Even though the R-value is higher per inch in a bale stacked on
edge, I
don't believe it is worth the effort of stacking walls this way.
There are
so many disadvantages to stacking bales on edge and I strongly
recommend you
don't bother with the idea. I have written a "top ten" list of
reasons not
to build with bales on edge on my website, www.StrawBale.com. You
can view
that article here <http://www.strawbale.com/top-10-no-bales-on-edge> (
http://www.strawbale.com/top-10-no-bales-on-edge) for more details
as to why
to avoid stacking on edge.
Best of luck and I hope your project runs smoothly from design to
completion.
Andrew
On Tue, Oct 12, 2010 at 3:57 AM, Sport Hotel, Jure Pozar <
jure.pozar@gmail...> wrote:
Dear all,
I am in the phase of designing our straw bale house and I have
heard that
if you lay the straw bale horizontaly it has the same isolation
conductivity as if laid vertical. Lets presume the bales? dimension
is 45 x
35 x 100 cm which would mean that laid horizontaly the strawbale
wall would
be 45 cm and verticaly would be 35 cm (the isolation at this second
option
is supposed to be better due to straws which are in vertical
position). Does
anybody know of tests performed and published of this particulat
subject. If
this is true you need much less strawbales to built your house. I
am of
course talking about post & beam method. Probably this would
present a
problem at loadbearing method. Does anybody know of any
difficulties when
building post & beam and bales put vertical?
I would appreciate any answer
Regards,
Jure Po?ar
____________________________________________________
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Strawbale@amper....muni.cz
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____________________________________________________
--
Andrew Morrison
Consultant, Teacher, Inspiring Change
====================================================
Learn How to Save Thousands of Dollars by Being Your Own Contractor
at:
www.BYOCTraining.com
===================================================
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====================================================
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====================================================
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Message: 3
Date: Sun, 10 Oct 2010 15:13:29 +0100
From: nora kasanicka <thegentlebuilder@googlemail...>
Subject: [Strawbale] www.strawbale-net.eu LAUNCHED!
To: strawbale_europe <strawbale@amper....muni.cz>,
GSBN@lists....com
Message-ID: <4CB1CA09.5030604@googlemail...>
Content-Type: text/plain; charset="iso-8859-1"
Greetings to all European Strawbalers!
in the name ofwww.strawbale-net.eu team i would like to invite you
all
to join us in what will hopefully become a vibrant online community of
Europe based strawbalers of all kinds!
Since two years ago we have been trying to put this project together
and
although it is still far from being perfect we feel we are ready now
to
share it with all of you. There is still a lot that could look
better on
the web and still some content to fill in but the main tools are there
and we would like to see them come alive now. Please join us and
register as a member atwww.strawbale-net.eu and publish your thoughts
in the forum, your events in the events section and any interesting
info
you'd like to share in the blog.
We are currently also working with the European Leonardo group and
they
will in the future be using our website as their "notice board" and
online working platform. This invitation is indeed to all the
strawbale
groups across Europe - we want to create and offer the tools for
easeful
and effective cooperation, communication and information sharing - so
that the European strawbale community can thrive! So let us know if
you
want to use our website!
I would like here to say my thanks to all who helped to get us where
we
are: most of all Vlado Brucker from Slovakia, our webmaster, Kuba
Wihan
and Barbara Jones for resources section (that is not there yet, but
soon
will be:), Charlotte Mannstead for helping me at the very beginning
and
at whose house in Denmark the idea of this website got born, Karen
Hjermind for nice crisp logo, Lindsay Round-Turner for a cool map
tool,
Oliver Swann for very cool search tool and many many more for
conversations, feedback, encouragement and most of all to all of you
for
your patience with us!
Please spread the news among your network!
on behalf of thewww.strawbale-net.eu
Nora Kasanicka
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Message: 4
Date: Tue, 12 Oct 2010 12:25:14 -0600
From: Derek Roff <derek@unm...>
Subject: Re: [Strawbale] Strawbale position
To: European strawbale building discussions
<strawbale@amper....muni.cz>, Jure Pozar <jure.pozar@gmail...>
Message-ID: <CCEA68EC8BFC71785C7646E4@d00-64-106-126-253....unm.edu>
Content-Type: text/plain; charset=iso-8859-1; format=flowed
I agree with Andrew that the research on R-Value of flat vs. on-edge
is
not totally rigorous, yet tends to indicate similar total R-value
for a
bale in either position (meaning higher R-value per inch/mm for bales
on edge). I have doubts about the general applicability of the
research, because the straw orientation in the bales that I have
worked
with is not terribly consistent. As Andrew mentions, it depends in
part on the baler.
If your climate isn't totally extreme, minor R-value differences
between bales don't matter. If your climate is extreme, consider
using
jumbo bales. Usually, it makes sense to put your energy into good
design, good detailing, and good roof insulation. Whether flat or
on-edge, strawbale walls give enough insulation, that other aspects of
the building have much more impact on energy conservation than the
minor differences in the different well-built strawbale walls might.
On the other hand, I disagree with Andrew on the validity of stacking
bales on edge. I like it. I note that many of the top builders, such
as Bill and Athena Steen, use or prefer on-edge stacking. Both
methods
work fine, in my opinion. Each has different advantages and
challenges. Here's my take on Andrew's 10 Reasons to Never Stack Your
Bales on Edge. I will list Andrew's reason text in full, and then my
response.
1. Strings on the exposed face mean no notching around posts and thus
a thermal break at each post.
I agree that the strings are exposed, which makes notching difficult.
I'm not a fan of notching, with bales flat or on edge, although it
makes sense in some designs. It is disingenuous to say that no
notching causes "a thermal break at each post". It would be foolish
to
design a thermal bridge (not "break") into your wall at every post
("thermal break" usually indicates something that stops heat flow; a
"thermal bridge" allows it). Common methods for avoiding a thermal
bridge include putting the posts fully inside the building envelope,
fully outside, or insulating behind the posts with straw flakes or
other insulation material. Or building Nebraska-style loadbearing
designs. Each option has pluses and minuses.
2. Bales are not sturdy. If you throw a bale off the stack it will
land
on the flat 99 out of 100 times, not on edge.
All testing shows that bales are plenty sturdy in either orientation.
Jeff Rupert's University of Colorado testing shows that bales on edge
were substantially stronger than bales laid flat, in handling extreme
loads (p.79, Design of Straw Bale Buildings: The State of the Art,
Bruce King, et al, 2006). However, the differences are not relevant
to
building, because bales are strong enough in either orientation, wall
loading in a house is much lower than in the tests, and the primary
loads on a wall will be carried by the plaster skins, in any case. Or
by the posts, if the building isn't loadbearing. I don't know if
Andrew has actually maintained careful records of the side his bales
fall on when he throws them off the stack, but this has nothing to do
with sturdiness of bales in a building. It strikes me as odd that
this
would be used as proof or explanation. Perhaps it's humor.
3. Any framing in the wall eliminates the running bond system, thus
weakening the walls.
Maybe I am missing something, but as I read it, this assertion is
completely false. Running bond stacking is used in all the on-edge
buildings that I have worked on, and most that I have seen in books
and
magazines. There are a few exceptions, of course, as there are for
flat-laid. Re-tying bales to custom lengths is needed to deal with
door and window framing, whether bales are laid flat or on edge. If
this is about notching, then it is a repeat of item 1. I've helped
with a dozen buildings with bales on edge, and they all had running
bonds and framing.
4. No weedwacking is possible to smooth the walls.
I'd go 50-50 on this one. Stacking on edge means walls are smoother
to
start with, and less weedwacking is needed. Removing the stray
irregularities seems easier to me, when the bales are on edge. On the
other hand, if you want to do major re-sculpting of a wall with a
weedwacker, stack your bales flat.
5. Running electrical is difficult because you have to cut chainsaw
grooves around strings.
Depends. Almost all the electrical runs in a wall are horizontal, and
the easiest option is to put the wiring between the bale courses. In
any case, horizontal runs at any height won't cross the strings. Some
codes/jurisdictions have special rules, such as putting wiring in
conduit. Vertical runs to switches and lights are likely to be near
doors, and on interior, non-strawbale walls. The strings have the
potential to be in the way in a few places, but the number is likely
to
be small. Or larger, if the wiring design is done with no thought to
the bales.
6. Corners are unsupported because you can?t notch the bales around
the
posts, therefore there is no overlap.
This seems like a repeat of number 1, with focus on the corners. It's
just as misleading. Every on-edge building that I have worked on,
seen
pictures of, or heard about, where bales meet at a corner, has
overlapped the corners in the same running bond as flat-laid bales.
Are these corners really "unsupported"? All the historical Nebraska
buildings were loadbearing, with no posts at all, in corners or
elsewhere. Many modern buildings are also loadbearing. So the
corners
can have plenty of support, with no posts at all. But supporting
posts
can also be placed at or near the corners when you stack on edge. See
item 1 for a couple of the options. I've found that notching bales at
the corner, where bales are coming from different directions on each
successive course, is even less fun than notching in the middle of a
bale. Worth doing, if that is your design, but other options exist.
7. Niche construction means cutting the strings and weakening the
wall.
It almost certainly means cutting the strings, but it is doubtful that
this weakens the wall. As mentioned above, the primary loads in a
wall
are taken by the plaster skins, or by the posts, and even unplastered
bales create walls that are vastly stronger than they need to be to
take building loads, according to testing. Windows and doors weaken
the wall vastly more than niches, but we've figured out how to deal
with that. Use similar strategies, if you are making a giant niche.
By the way, some very well respected builders, such as Tom Rijven and
David Lanfear, cut all the strings on every bale, in order to improve
the strength and efficiency of their walls. Chris Magwood and others
have experimented with stacking a continuous wall, and then cutting
out
window openings with a chainsaw. They cut a lot of strings, and their
walls seem fine.
8. The shape of the bales requires more stuffing when on edge.
Maybe, but I doubt it. The ends of the bales interface in the same
way
with either orientation, so the amount of stuffing between a pair of
bale ends is the same. The depth of the wall is less with on edge
stacking, and a wall needs fewer courses of bales for a given height.
So I think on edge is ahead. If you pre-compress your wall, which I
favor in every case, then on-edge bales conform to each other more,
between the courses, than flat-laid bales, again leading to less
stuffing. But both methods still require a lot of stuffing, for my
tastes.
9. The exposed surface of the bale has less ?tooth? for plaster than
when the bales are stacked on the flat.
I agree. The difference is noticeable, but not overwhelming.
10. Wall settling may be more as the strength of the straw bale is not
from side to side but from top to bottom.
The best laboratory testing, which I quoted under item 2 above, is
that
strawbales are stronger on edge. Many people wonder about that test,
but it is clear that walls are strong enough in either orientation,
and
again, the primary loads are carried by the plaster skins or the
posts.
The best historical testing is the 100+ year old Nebraska buildings.
They are built with bales on edge, at least in the ones I know of that
have been verified. In many of these buildings, you can tell bale
orientation from the photos taken during construction, and from truth
windows. They are loadbearing, and the windows and doors are intact,
so there hasn't been much settling.
So my scoring is a bit different than Andrew's. I agree with one of
his points, and there are a few where I am in partial agreement. He
is
welcome to his opinions and preferences, but I'm bothered by the
inaccurate reporting and illogical arguments in some of his points.
My
belief is that you can build great buildings either way, and that
there
are pluses and minuses for any and every building choice.
I will add a few words on one question that didn't enter into Andrew's
list. If you want to shape the bales or the wall in certain ways,
there may be an advantage to one method or the other. For circular
buildings of small to modest radius, it's easier to form (distort)
each
bale into part of the needed arc, if they are on edge. But you have
to
sew the inside strings back to the bale, to follow the reshaped bale.
It's not difficult, but it takes extra time. Putting an arc in a
flat-laid bale is harder (especially 3-string rice bales), but the
strings are more cooperative, except in the smallest buildings. For
large, round buildings, the bales don't need to be distorted.
Around windows, it's easier to carve a small bullnose curve on a
flat-laid bale. For a bigger (more normal-sized) curve, one of the
strings of flat-laid bales gets in the way of carving your curve. Of
course, there are ways to deal with that, such as running an extra
string or two, to pull the main string off its course at the end of
the
bale.
When carving a large arc on the end of a flat-laid bale, the straws
tend to stick out in all directions like Pappy's beard in the Popeye
cartoons, which makes plastering a beautiful curve a little more
difficult. It's still quite doable. Re-tying an on-edge bale to
approximate the bullnose curve shape that you want is possible with
many bales, although again harder with rice. It means re-tying every
bale around the window or door, but at least half of those have to be
re-tied in most designs, flat or edge stacked. Some people would
rather build the curve with lath, and stuff it with straw. I'm not a
fan of that.
The more low-relief sculpting that you plan, the more advantageous it
is to lay your bales flat.
I hope this helps,
Derelict
--On Tuesday, October 12, 2010 7:16 AM -0700 Andrew Morrison
<Andrew@StrawBale...> wrote:
Hello Jure. There are some studies out there about the insulation
value of straw bales stacked horizontally (on the flat) and
vertically (on edge); however, I do not think that any of them are
terribly accurate. In each, there are details that are subjective. I
do believe that they all conclude that the straw orientation does
indeed affect the insulation value of the bales, thus making bales
stacked on edge higher R-value per inch than bales stacked
horizontally. This effectively gives you the same R-value for the
bales stacked either way, simply allowing you to use less space in
your home for the actual wall thickness. That said, many new baling
machines are orienting the straw differently, or not at all (chopped
straw from combines for example is so small that the straw
orientation is every which way).
Even though the R-value is higher per inch in a bale stacked on edge,
I don't believe it is worth the effort of stacking walls this way.
There are so many disadvantages to stacking bales on edge and I
strongly recommend you don't bother with the idea. I have written a
"top ten" list of reasons not to build with bales on edge on my
website, www.StrawBale.com. You can view that article here
(http://www.strawbale.com/top-10-no-bales-on-edge) for more details
as to why to avoid stacking on edge.
Best of luck and I hope your project runs smoothly from design to
completion.
Andrew
On Tue, Oct 12, 2010 at 3:57 AM, Sport Hotel, Jure Pozar
<jure.pozar@gmail...> wrote:
Dear all,
I am in the phase of designing our straw bale house and I have heard
that if you lay the straw bale? horizontaly it has the same isolation
conductivity as if laid vertical. Lets presume the bales? dimension
is 45 x 35 x 100 cm which would mean that laid horizontaly the
strawbale wall would be 45 cm and verticaly would be 35 cm (the
isolation at this second option is supposed to be better due to
straws which are in vertical position). Does anybody know of tests
performed and published of this particulat subject. If this is true
you need much less strawbales to built your house. I am of course
talking about post & beam method. Probably this would present a
problem at loadbearing method. Does anybody know of any difficulties
when building post & beam and bales put vertical?
I would appreciate any answer
Regards,
Jure Po?ar
------------------------------
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End of Strawbale Digest, Vol 59, Issue 8
****************************************