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Re: GSBN:More moisture problems - Southern California



Hi,

Kuba will install data loggers in our house. He is going to write his thesis
on moisture issues and might plug in by than. "High Winds" are blowing
horizontally rain in the house. The straw-bales in the roof are secured,
those in the walls not yet placed, we need rain gutters first and
windows/doors in...


Best wishes, Martin


----- Original Message -----
From: "Paul Lacinski" paul@...
To: "GSBN" GSBN@...
Sent: Thursday, May 19, 2005 7:36 AM
Subject: Re: GSBN:More moisture problems - Southern California


> Bob,
>
> We have been dealing with some moisture issues lately as well, which
> are not as dramatic as yours, but are troubling nonetheless.  I'm
> gathering data at the moment and will be writing to the list before
> too long.  This is all a sign that straw bale construction is growing
> up, though I agree that it's very hard for the people on whom the
> problems land.
>
> I don't have any documetable answers to any of your questions, but I
> do have another question for you.  You said:
> " +- 40% within the center of the bales. Other reading surrounding
> the affected areas ranged between 15 and 20%. "  It would seem
> important to look at the moisture levels at the interior and exterior
> of the walls in these areas where the center was so wet.  Maybe you
> have done this, but it's not clear from the language in your posting.
> My experience has been that wetness from rain on the wall surface (or
> even potential wetness from rain- in our climate it can be difficult
> to separate rain from condensation as sources) does not penetrate
> more than an inch or two into the bale.  It is difficult to imagine
> rainwater making its way to the center of the bale wall, unless
> through a leak.  And it's nearly impossible to imagine it making its
> way to the interior.  It may be possible in the 15-20% regions to
> document some pattern of striation through the wall section- is it
> consistently wettest toward the interior, middle, or exterior?  In
> any situation that is only an exaggeration of the normal conditions-
> like lots of rain against the wall surface, instead of the normal
> amounts, you would be able to pick out a pattern of dampness that was
> an exaggeration of a normal pattern- wetter toward the outside, dryer
> as you move in.  If this is not the case, it would seem that the
> water is coming from somewhere else- like a roof leak.  This could be
> useful in convincing the owner.
>
> To get closer to an answer to your last question, while also giving
> the owner something constructive to focus on,  I'm wondering whether
> you can find an isolated section of wall on which to conduct an
> accelerated drying experiment.  You could apply heat to the interior
> face (maybe an electric blanket against the wall with a couple of
> regular blankets behind it?) and then consistently test moisture
> content from the outside.  If you cover your holes well (duct tape
> seems to work) you should be able to re-use them without throwing off
> your readings.  If you drill the holes a bit oversized, in successive
> readings you can change the angle of the probe, to go into fresh
> straw.  You might also put a thermometer behind the blanket at the
> interior wall surface, and chart the temperature there. A max-min
> thermometer could be helpful, though I would think the termperature
> would remain pretty consistent.  Then a person who is adept with
> these types of numbers might be able to extrapolate your readings to
> guess at a drying rate under more normal temperatures.
>
> Best of luck and please keep us updated on your progress.
>
> Paul
>
>
> >Good day all,
> >
> >Sorry for some cross-posting to a couple of other lists.
> >
> >Like the Straw Wolf and Danny Buck, we have a real problem with
> >"moisture" in the walls of a project in our area. No, it isn't one
> >of mine, but it is this kind of "problem" that can give Straw Bale
> >Construction a bad name, so it is everyone's problem.
> >
> >I do remember the exchanges regarding the SB that Danny was working
> >on, but was kicking myself because I hadn't saved them - Thank you
> >Joyce for "reminding" me that it had been reprinted in issue #49 of
> >TLS, and thank you all for your extremely valuable insight and
> >sharing your experiences. If we can actually root out the sources of
> >the moisture, and come to some conclusions, I hope to be able to
> >write some sort of analysis and summary for future reference. I
> >think your past and future input on the subject will be invaluable.
> >~bb
> >
> >
> >
> >This is a large home (3,000 Sf) with lots of amenities, and the
> >parapet style is consistent with other projects by the same
> >Architect.
> >
> >
> >
> >This year was one of those few "wet" years that we have, and in the
> >area of the project, (Ramona, San Diego County, CA - USA) the
> >rainfall for the season was ~25 inches; the 2nd highest on record.
> >Some of the rains were very heavy downpours and much of those were
> >wind-driven directly into the South and West-facing parapet walls.
> >
> >Several items of particular note: Water was detected dripping out of
> >the kitchen soffit after only 1-1/2 days of rain, and moisture
> >content readings, principally grouped in 6 different locations, were
> >recorded at +- 40% within the center of the bales. Other reading
> >surrounding the affected areas ranged between 15 and 20%. While the
> >current readings indicate some areas were wetter than others, I
> >believe (speculating) that the leakage occurred pretty much all
> >along the parapet walls on the South and West sides of the house.
> >There were wet walls elsewhere, but perhaps they were caused by
> >different problems. The architect just reminded me that there were
> >also quite a few wet spots in the wood-framed portions of the home,
> >which makes this even more interesting.
> >
> >All window and door opening were sealed with bituminous material
> >between the openings and the frames. I have been told that a
> >moisture barrier was used to cover the wooden parapets and lapped
> >over the bales.
> >
> >The plaster was a 3-coat cement stucco - I am still investigating
> >whether lime was used in the mix, but it seems unlikely. It seems
> >more probable that the plaster was more of a moisture barrier than a
> >likely source as the point of water entry. No sealer was applied to
> >the stucco. There is some cracking, both horizontal and vertical,
> >and while a few are potentially large enough to allow water into the
> >bale interior, at best they could only account for some of the water
> >at some locations. There are also hairline cracks; and I guess the
> >thinking is that the rainfall may have penetrated all 3 plaster
> >layers.
> >
> >The framing details on the plans don't really tell me a lot about
> >the construction of the parapet, other than it seems to be an
> >extensions of the posts, and I am assuming that it was sheathed,
> >papered, lathed and plastered. The roofing detail sheet is a
> >cookie-cutter and doesn't even illustrate a parapet of this type.
> >
> >I have compared notes with Mark Tighe, another experienced bale
> >builder and who also examined the house - each of our independent
> >investigations lasted about 3 hours. We both came to pretty much the
> >same conclusion that nothing that we could see would account for all
> >of the water that appears to have entered the wall up around the
> >(wooden) parapet extension. There was at least some penetration
> >there because there were consistent wet readings all along the top
> >of the walls at the ceiling. We can't tell how much entered there or
> >how much may have entered down the wall.
> >
> >It has been suggested that where the first water was spotted, one
> >potential scenario is that water penetrated the stucco (from where
> >is yet unknown) and ran down the inside face of the interior plaster
> >until it hit the box beam kitchen soffit, where it poured into the
> >soffit and out the light fixture. This might account for the kitchen
> >leak, but in the few plastered test walls that I have (struggled to)
> >removed the plaster from, there wasn't what you would call a lot of
> >room for water to travel through very rapidly. Also, how would the
> >water get to the interior plaster surface? Water doesn't flow very
> >well across bales.
> >
> >To make this all a bit more interesting, the owner has grasped onto
> >the idea of installing a sheet moisture barrier between the plaster
> >and the bales when the time for repair comes (not that I blame him
> >at this point). I and others (and he has read) have explained that
> >this is likely to cause moisture to be trapped within the cavity and
> >in itself cause rot. He said that he had heard that, but has yet to
> >see evidence that is really true. Not that is shakes my faith in the
> >truth of the supposition, come to think of it, other than from the
> >Straw Wolf, neither have I, though John Straube has published some
> >very convincing test data that certainly makes the case.
> >
> >My next step is to contact the contractor, that is now out of state,
> >and see if they can give some insight as to the potential failures.
> >I have requested that the owners create a grid of test holes from
> >the inside, where the others are, and really see if we can figure
> >out just where and how widespread the problem really is.
> >
> >I feel for these folks, fearing the worst (whatever that is) and
> >about to watch parts of their house being demolished. Not happy
> >campers and I know that everyone feels badly.
> >
> >I would appreciate hearing your thoughts on the subject.
> >
> >At the moment, the owners are pretty upset that they are in this
> >position, and are now questioning anyone's point of view unless
> >there is documented evidence to back the assertions up. I can't
> >fault them for that.
> >
> >Their questions are as follows - please do what you can to provide
> >some sort of documentation and/or experiences supporting your
> >thoughts.
> >
> >
> >
> >1) Do parapet walls "always" allow moisture penetration? Any
> >experiences or testing that might indicate why some did and others
> >didn't?
> >
> >2) Does 3-coat cement plaster (stucco) allow enough water to
> >penetrate a wall and substantially "soak" the bales? I seem to
> >recall that Dr. Straube's tests involved capillary uptake, but I
> >don't think that if I had the rest results in front of me I would
> >necessarily understand them without a really clear explanation. How
> >would this compare to rainfall on a vertical wall surface?
> >
> >3) Will a sheet moisture barrier between the bales and the plaster
> >cause the bales to decompose?
> >
> >4) Will a non permeable stucco function the same as a sheet moisture
> >barrier and cause the bales to decompose?
> >
> >5) Is there any rule of thumb that would give us an indication that
> >over that moisture content % the bales won't likely dry out, but
> >under that % they will likely dry out. I understand that is a
> >"difficult" question because much will depend on the drying
> >conditions, but I was wondering if someone had reached some
> >conclusion made from personal observation in their experiences.
> >
> >I will pass on any developments as I can.
> >
> >
> >
> >My thanks in advance for any insight, experiences, information on
> >other failures and documentation of the causes. If at all possible,
> >I am in hopes that we will be able to pass on any information that
> >will assist those in the future make "better" and informed decisions.
> >
> >Regards~
> >
> >bb
> >
> >
> >Bob Bolles
> >Bob@...
> >www.StrawBaleHouse.com
> >Join our Community bulletin board
> >   casbasouth-subscribe@...
> >
> >
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> >---
> >----
> >GSBN is an invitation-only forum of key individuals and
> >representatives of regional straw construction organizations. The
> >costs of operating this list are underwritten by The Last Straw
> >Journal in exchange for use of the GSBN as an advisory board and
> >technical editing arm.
> >
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>
> --
> Paul M. Lacinski
> GreenSpace Collaborative
> Sidehill Farm
> Mail: PO Box 107
> Packages: 463 Main Street
> Ashfield, MA 01330 USA
> +1   413 628 3800
>
> View excerpts from Serious Straw Bale at:
> <a  target="_blank" href="http://www.chelseagreen.com/2004/items/seriousstrawbale";>http://www.chelseagreen.com/2004/items/seriousstrawbale</a>
> ----
> GSBN is an invitation-only forum of key individuals and representatives of
regional straw construction organizations. The costs of operating this list
are underwritten by The Last Straw Journal in exchange for use of the GSBN
as an advisory board and technical editing arm.
>
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send email to GSBN@...HELP in the SUBJECT line.
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