Lots to comment on here and I decided to take my comments back to my <a href="http://www.strawbale.com/top-10-no-bales-on-edge">blog</a> (<a href="http://www.strawbale.com/top-10-no-bales-on-edge">http://www.strawbale.com/top-10-no-bales-on-edge</a>) rather than continue with long back and forth posts both here and there. I hope you will take a moment to read my response to Derek's email. Clearly we disagree, which is fine. I hope you will consider both points of view before you make any decisions on your own projects.<br>
<br>Andrew<br><br><div class="gmail_quote">On Tue, Oct 12, 2010 at 11:25 AM, Derek Roff <span dir="ltr"><<a href="mailto:derek@unm...">derek@unm...</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin: 0pt 0pt 0pt 0.8ex; border-left: 1px solid rgb(204, 204, 204); padding-left: 1ex;">
I agree with Andrew that the research on R-Value of flat vs. on-edge is<br>
not totally rigorous, yet tends to indicate similar total R-value for a<br>
bale in either position (meaning higher R-value per inch/mm for bales<br>
on edge). I have doubts about the general applicability of the<br>
research, because the straw orientation in the bales that I have worked<br>
with is not terribly consistent. As Andrew mentions, it depends in<br>
part on the baler.<br>
<br>
If your climate isn't totally extreme, minor R-value differences<br>
between bales don't matter. If your climate is extreme, consider using<br>
jumbo bales. Usually, it makes sense to put your energy into good<br>
design, good detailing, and good roof insulation. Whether flat or<br>
on-edge, strawbale walls give enough insulation, that other aspects of<br>
the building have much more impact on energy conservation than the<br>
minor differences in the different well-built strawbale walls might.<br>
<br>
On the other hand, I disagree with Andrew on the validity of stacking<br>
bales on edge. I like it. I note that many of the top builders, such<br>
as Bill and Athena Steen, use or prefer on-edge stacking. Both methods<br>
work fine, in my opinion. Each has different advantages and<br>
challenges. Here's my take on Andrew's 10 Reasons to Never Stack Your<br>
Bales on Edge. I will list Andrew's reason text in full, and then my<br>
response.<br>
<br>
1. Strings on the exposed face mean no notching around posts and thus<br>
a thermal break at each post.<br>
<br>
I agree that the strings are exposed, which makes notching difficult.<br>
I'm not a fan of notching, with bales flat or on edge, although it<br>
makes sense in some designs. It is disingenuous to say that no<br>
notching causes "a thermal break at each post". It would be foolish to<br>
design a thermal bridge (not "break") into your wall at every post<br>
("thermal break" usually indicates something that stops heat flow; a<br>
"thermal bridge" allows it). Common methods for avoiding a thermal<br>
bridge include putting the posts fully inside the building envelope,<br>
fully outside, or insulating behind the posts with straw flakes or<br>
other insulation material. Or building Nebraska-style loadbearing<br>
designs. Each option has pluses and minuses.<br>
<br>
2. Bales are not sturdy. If you throw a bale off the stack it will land<br>
on the flat 99 out of 100 times, not on edge.<br>
<br>
All testing shows that bales are plenty sturdy in either orientation.<br>
Jeff Rupert's University of Colorado testing shows that bales on edge<br>
were substantially stronger than bales laid flat, in handling extreme<br>
loads (p.79, Design of Straw Bale Buildings: The State of the Art,<br>
Bruce King, et al, 2006). However, the differences are not relevant to<br>
building, because bales are strong enough in either orientation, wall<br>
loading in a house is much lower than in the tests, and the primary<br>
loads on a wall will be carried by the plaster skins, in any case. Or<br>
by the posts, if the building isn't loadbearing. I don't know if<br>
Andrew has actually maintained careful records of the side his bales<br>
fall on when he throws them off the stack, but this has nothing to do<br>
with sturdiness of bales in a building. It strikes me as odd that this<br>
would be used as proof or explanation. Perhaps it's humor.<br>
<br>
3. Any framing in the wall eliminates the running bond system, thus<br>
weakening the walls.<br>
<br>
Maybe I am missing something, but as I read it, this assertion is<br>
completely false. Running bond stacking is used in all the on-edge<br>
buildings that I have worked on, and most that I have seen in books and<br>
magazines. There are a few exceptions, of course, as there are for<br>
flat-laid. Re-tying bales to custom lengths is needed to deal with<br>
door and window framing, whether bales are laid flat or on edge. If<br>
this is about notching, then it is a repeat of item 1. I've helped<br>
with a dozen buildings with bales on edge, and they all had running<br>
bonds and framing.<br>
<br>
4. No weedwacking is possible to smooth the walls.<br>
<br>
I'd go 50-50 on this one. Stacking on edge means walls are smoother to<br>
start with, and less weedwacking is needed. Removing the stray<br>
irregularities seems easier to me, when the bales are on edge. On the<br>
other hand, if you want to do major re-sculpting of a wall with a<br>
weedwacker, stack your bales flat.<br>
<br>
5. Running electrical is difficult because you have to cut chainsaw<br>
grooves around strings.<br>
<br>
Depends. Almost all the electrical runs in a wall are horizontal, and<br>
the easiest option is to put the wiring between the bale courses. In<br>
any case, horizontal runs at any height won't cross the strings. Some<br>
codes/jurisdictions have special rules, such as putting wiring in<br>
conduit. Vertical runs to switches and lights are likely to be near<br>
doors, and on interior, non-strawbale walls. The strings have the<br>
potential to be in the way in a few places, but the number is likely to<br>
be small. Or larger, if the wiring design is done with no thought to<br>
the bales.<br>
<br>
6. Corners are unsupported because you can’t notch the bales around the<br>
posts, therefore there is no overlap.<br>
<br>
This seems like a repeat of number 1, with focus on the corners. It's<br>
just as misleading. Every on-edge building that I have worked on, seen<br>
pictures of, or heard about, where bales meet at a corner, has<br>
overlapped the corners in the same running bond as flat-laid bales.<br>
Are these corners really "unsupported"? All the historical Nebraska<br>
buildings were loadbearing, with no posts at all, in corners or<br>
elsewhere. Many modern buildings are also loadbearing. So the corners<br>
can have plenty of support, with no posts at all. But supporting posts<br>
can also be placed at or near the corners when you stack on edge. See<br>
item 1 for a couple of the options. I've found that notching bales at<br>
the corner, where bales are coming from different directions on each<br>
successive course, is even less fun than notching in the middle of a<br>
bale. Worth doing, if that is your design, but other options exist.<br>
<br>
7. Niche construction means cutting the strings and weakening the wall.<br>
<br>
It almost certainly means cutting the strings, but it is doubtful that<br>
this weakens the wall. As mentioned above, the primary loads in a wall<br>
are taken by the plaster skins, or by the posts, and even unplastered<br>
bales create walls that are vastly stronger than they need to be to<br>
take building loads, according to testing. Windows and doors weaken<br>
the wall vastly more than niches, but we've figured out how to deal<br>
with that. Use similar strategies, if you are making a giant niche.<br>
By the way, some very well respected builders, such as Tom Rijven and<br>
David Lanfear, cut all the strings on every bale, in order to improve<br>
the strength and efficiency of their walls. Chris Magwood and others<br>
have experimented with stacking a continuous wall, and then cutting out<br>
window openings with a chainsaw. They cut a lot of strings, and their<br>
walls seem fine.<br>
<br>
8. The shape of the bales requires more stuffing when on edge.<br>
<br>
Maybe, but I doubt it. The ends of the bales interface in the same way<br>
with either orientation, so the amount of stuffing between a pair of<br>
bale ends is the same. The depth of the wall is less with on edge<br>
stacking, and a wall needs fewer courses of bales for a given height.<br>
So I think on edge is ahead. If you pre-compress your wall, which I<br>
favor in every case, then on-edge bales conform to each other more,<br>
between the courses, than flat-laid bales, again leading to less<br>
stuffing. But both methods still require a lot of stuffing, for my<br>
tastes.<br>
<br>
9. The exposed surface of the bale has less “tooth” for plaster than<br>
when the bales are stacked on the flat.<br>
<br>
I agree. The difference is noticeable, but not overwhelming.<br>
<br>
10. Wall settling may be more as the strength of the straw bale is not<br>
from side to side but from top to bottom.<br>
<br>
The best laboratory testing, which I quoted under item 2 above, is that<br>
strawbales are stronger on edge. Many people wonder about that test,<br>
but it is clear that walls are strong enough in either orientation, and<br>
again, the primary loads are carried by the plaster skins or the posts.<br>
The best historical testing is the 100+ year old Nebraska buildings.<br>
They are built with bales on edge, at least in the ones I know of that<br>
have been verified. In many of these buildings, you can tell bale<br>
orientation from the photos taken during construction, and from truth<br>
windows. They are loadbearing, and the windows and doors are intact,<br>
so there hasn't been much settling.<br>
<br>
<br>
So my scoring is a bit different than Andrew's. I agree with one of<br>
his points, and there are a few where I am in partial agreement. He is<br>
welcome to his opinions and preferences, but I'm bothered by the<br>
inaccurate reporting and illogical arguments in some of his points. My<br>
belief is that you can build great buildings either way, and that there<br>
are pluses and minuses for any and every building choice.<br>
<br>
I will add a few words on one question that didn't enter into Andrew's<br>
list. If you want to shape the bales or the wall in certain ways,<br>
there may be an advantage to one method or the other. For circular<br>
buildings of small to modest radius, it's easier to form (distort) each<br>
bale into part of the needed arc, if they are on edge. But you have to<br>
sew the inside strings back to the bale, to follow the reshaped bale.<br>
It's not difficult, but it takes extra time. Putting an arc in a<br>
flat-laid bale is harder (especially 3-string rice bales), but the<br>
strings are more cooperative, except in the smallest buildings. For<br>
large, round buildings, the bales don't need to be distorted.<br>
<br>
Around windows, it's easier to carve a small bullnose curve on a<br>
flat-laid bale. For a bigger (more normal-sized) curve, one of the<br>
strings of flat-laid bales gets in the way of carving your curve. Of<br>
course, there are ways to deal with that, such as running an extra<br>
string or two, to pull the main string off its course at the end of the<br>
bale.<br>
<br>
When carving a large arc on the end of a flat-laid bale, the straws<br>
tend to stick out in all directions like Pappy's beard in the Popeye<br>
cartoons, which makes plastering a beautiful curve a little more<br>
difficult. It's still quite doable. Re-tying an on-edge bale to<br>
approximate the bullnose curve shape that you want is possible with<br>
many bales, although again harder with rice. It means re-tying every<br>
bale around the window or door, but at least half of those have to be<br>
re-tied in most designs, flat or edge stacked. Some people would<br>
rather build the curve with lath, and stuff it with straw. I'm not a<br>
fan of that.<br>
<br>
The more low-relief sculpting that you plan, the more advantageous it<br>
is to lay your bales flat.<br>
<br>
I hope this helps,<br>
<br>
Derelict<br>
<br>
<br>
--On Tuesday, October 12, 2010 7:16 AM -0700 Andrew Morrison<br>
<div><div></div><div class="h5"><Andrew@StrawBale...> wrote:<br>
<br>
> Hello Jure. There are some studies out there about the insulation<br>
> value of straw bales stacked horizontally (on the flat) and<br>
> vertically (on edge); however, I do not think that any of them are<br>
> terribly accurate. In each, there are details that are subjective. I<br>
> do believe that they all conclude that the straw orientation does<br>
> indeed affect the insulation value of the bales, thus making bales<br>
> stacked on edge higher R-value per inch than bales stacked<br>
> horizontally. This effectively gives you the same R-value for the<br>
> bales stacked either way, simply allowing you to use less space in<br>
> your home for the actual wall thickness. That said, many new baling<br>
> machines are orienting the straw differently, or not at all (chopped<br>
> straw from combines for example is so small that the straw<br>
> orientation is every which way).<br>
><br>
> Even though the R-value is higher per inch in a bale stacked on edge,<br>
> I don't believe it is worth the effort of stacking walls this way.<br>
> There are so many disadvantages to stacking bales on edge and I<br>
> strongly recommend you don't bother with the idea. I have written a<br>
> "top ten" list of reasons not to build with bales on edge on my<br>
> website, <a href="http://www.StrawBale.com" target="_blank">www.StrawBale.com</a>. You can view that article here<br>
> (<a href="http://www.strawbale.com/top-10-no-bales-on-edge" target="_blank">http://www.strawbale.com/top-10-no-bales-on-edge</a>) for more details<br>
> as to why to avoid stacking on edge.<br>
><br>
> Best of luck and I hope your project runs smoothly from design to<br>
> completion.<br>
><br>
> Andrew<br>
><br>
><br>
> On Tue, Oct 12, 2010 at 3:57 AM, Sport Hotel, Jure Pozar<br>
> <<a href="mailto:jure.pozar@gmail...">jure.pozar@gmail...</a>> wrote:<br>
><br>
><br>
> Dear all,<br>
><br>
> I am in the phase of designing our straw bale house and I have heard<br>
> that if you lay the straw bale horizontaly it has the same isolation<br>
> conductivity as if laid vertical. Lets presume the bales? dimension<br>
> is 45 x 35 x 100 cm which would mean that laid horizontaly the<br>
> strawbale wall would be 45 cm and verticaly would be 35 cm (the<br>
> isolation at this second option is supposed to be better due to<br>
> straws which are in vertical position). Does anybody know of tests<br>
> performed and published of this particulat subject. If this is true<br>
> you need much less strawbales to built your house. I am of course<br>
> talking about post & beam method. Probably this would present a<br>
> problem at loadbearing method. Does anybody know of any difficulties<br>
> when building post & beam and bales put vertical?<br>
><br>
> I would appreciate any answer<br>
><br>
> Regards,<br>
><br>
</div></div>> Jure PoÏar<br>
<div><div></div><div class="h5"><br>
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</div></div></blockquote></div><br><br clear="all"><br>-- <br>Andrew Morrison<br>Consultant, Teacher, Inspiring Change<br><br>====================================================<br>Learn How to Save Thousands of Dollars by Being Your Own Contractor at:<br>
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