[GSBN] SB Overhangs (was Big News!)

Wed Aug 25 12:49:52 UTC 2010

Hi Graeme,

I¹ll send you the SB code off list.

Re: the overhangs, what do you do with multi-story or tall walls?  Do you
have roof at typical first floor ceiling height in addition to the upper
roof?

I will definitely consider putting such a table into the SB code.  I saw
Bruce¹s vote of agreement, and wonder if anyone else strongly agrees or
disagrees that overhangs be code-mandated for strawbale.

Overhangs are generally a very good idea for SB, and I consider them ³good
practice² or ³best practice².  I don¹t know if they are at the level of
³minimum practice², which is typically the threshold of code language,
although all of that is open to considerable debate.   Also in your table
you account for wind as a factor, but not rainfall.  If your table were
applied to desert climates, it might be unfairly restrictive (although some
desert climates receive concentrated periods of rain).

In an earlier iteration of the code I prohibited strawbale parapets, but for
a few reasons decided to instead be silent on the issue.

Martin

On 8/24/10 4:11 PM, "Graeme North" <graeme at ecodesign.co.nz> wrote:

>  HI Martin
> 
> firstly my congratulations -
> 
> and yes, I would really appreciate a word document I can make comment on
> 
> From my neck of the woods, one of the overriding issues I encounter time and
> time again is that of good weather protection from wind driven rain in our
> decidedly pluvian and humid climate - something that gets skittered  around in
> most books and references.
> 
> I think we need a prescriptive starting point.  In the NZ Earth Building
> Standards NZS 4299 we relate wind zone. eaves height (vertical exposed wall
> height), and roof overhang width to give  MIMIMUM roof overhangs as follows -
> 
> 
> Wind Zone   - Ratio of eave height to width
> Low  (at ULS 32m/s) 4:1  (600mm over a 2400 wall)
> Medium (37m/s) 8:3
> High (44 m/s) 3:2
> Very High   (50 m/s) 1:1  (or in other words a full verandah)
> 
>    
> We developed this table after leaks and some degradation of material in some
> earthen structures and I can report that there has been no reported problem
> since we adopted this.
> 
> It is my contention that straw buildings are at least as moisture sensitive as
> earthen buildings and I would suggest that this sort of table be regarded a
> good starting point for calculating minimum roof overhangs for
> direct-plastered external strawbale walls, a recommendation that could
> possibly be worked back (or exceeded) after local weather or site assessment,
> or possibly a service history of locally developed techniques.
> 
> It may seem a but draconian to some but for my money the biggest problem with
> strawbale buildings, in humid wet climates at least, seems to be that of
> providing adequate primary weather protection, in the form of eaves, or rain
> screening, and lack of good practical prescriptive guidance on this subject.
> 
> 
> Comments welcome
> 
> 
> 
> 
>  
> Graeme (in bossy standards writing mode) North
>  
> Graeme North Architects
> 49 Matthew Road
> RD1
> Warkworth
> tel/fax +64 (0)9 4259305
>  
> graeme at ecodesign.co.nz
> www.ecodesign.co.nz
> 
>  
> 
> On 23/08/2010, at 5:32 PM, martin hammer wrote:
> 
>>  Everyone,
>>  
>>  Lars Keller asked the below question so I thought I would answer to all in
>> case others are interested.  I¹ll set a deadline of September 30th for anyone
>> wanting to comment on the strawbale code as in the second draft of the IGCC.
>>  
>>  Thanks.
>>  
>>  Martin
>>  
>>  
>>  On 8/22/10 9:36 PM, "Lars Keller" <larskeller at gmail.com> wrote:
>>  
>>  
>>> Dear Martin,
>>>  What is the deadline for comments to you ?
>>>  Best regards,
>>>  Lars Keller
>>>  
>>>  On 22 August 2010 03:36, martin hammer <mfhammer at pacbell.net> wrote:
>>>  
>>>> Hello friends on the GSBN,
>>>>  
>>>>  My voice has been conspicuously absent on this subject, so I thought I
>>>> would weigh in.
>>>>  
>>>>  First, thanks for the words of appreciation.  I was pleasantly surprised
>>>> to hear the news from David on Monday.  I think this strawbale code
>>>> document is very good, but there are a number of reasons I didn¹t think it
>>>> would go through to the next step.  I thought both the Earthen Materials
>>>> proposal (referencing the recently revised ASTM standard that Bruce, David
>>>> in earlier years, and others worked so hard on) and the Straw-Clay proposal
>>>> I co-authored with Paula Baker-Laporte, had better chances.  I might
>>>> propose them again in the upcoming Code Change Proposal phase (once IGCC
>>>> committee concerns are addressed).
>>>>  
>>>>  Much blood, sweat, and a few tears have gone into this SB code since 2003,
>>>> when I began writing it at the request of the State of California (they
>>>> asked Bruce, Bruce asked me . . .).  I¹ve had very good input from others
>>>> along the way, including members of this list (David Eisenberg, Bruce King,
>>>> Dan Smith, Bob Theis, Tim Kennedy, John Swearingen, Bill Steen, Kelly
>>>> Lerner) (apology if I¹ve missed anyone), and others not on this list,
>>>> notably civil engineering professor Mark Aschheim.
>>>>  
>>>>  Because it started as a California code, and because there are great SB
>>>> experts in northern CA where I live, the code might be a bit
>>>> California-centric (with particular attention to seismic issues).  However
>>>> I¹ve always wanted it to be broadly applicable and I welcome broader,
>>>> global input at this time.  I expect to propose adjustments during the next
>>>> IGCC review phase.  If it remains in the IGCC and goes the way codes often
>>>> do, some version of this might show up at your building official¹s door and
>>>> then your strawbale door in Australia, South Africa, or who knows where.
>>>> And although I think there¹s much to like, I can almost guarantee you can
>>>> find something you don¹t like.  So . . .
>>>>  
>>>>  If you want to see and comment on the proposed code you can ask me to
>>>> e-mail the proposed SB code (by itself) to you as a word document, and then
>>>> e-mail me your comments or send it back with ³track changes².  OR you can
>>>> go to:   http://www.iccsafe.org/CS/IGCC/Pages/Comments0810.aspx , and
>>>> download all Public Comments under the ³Complete Document² subheading
>>>> (Strawbale Construction is Comment #5-136).  You can then e-mail your
>>>> comments to me (not to ICC).  I¹m also open to comments on #5-134
>>>> Straw-Clay, and #5-135 Earthen Materials.  If you want to understand the
>>>> IGCC process and schedule, you can go to:
>>>> http://www.iccsafe.org/cs/IGCC/Pages/PublicVersionDevelopment.aspx
>>>>  
>>>>  In addition, I want to clarify that:
>>>>  
>>>>  
>>>> * Strawbale is not yet in the IGCC.  That¹s because it isn¹t finalized (and
>>>> SB could even be entirely removed).
>>>> * Even if included in the final version, the IGCC applies only to
>>>> commercial and high-rise residential, AND only in jurisdictions that adopt
>>>> the IGCC.  So it would have limited application.
>>>> *  
>>>> 
>>>>  That said, this approval is still a very good thing.  And if it does make
>>>> it to the finish line of the IGCC, it would probably then migrate to the
>>>> IBC in the next code cycle, and then to a jurisdiction near you.  I even
>>>> see the possibility of jurisdictions adopting it or informally using it for
>>>> all occupancies, even before reaching the IBC.  John Swearingen¹s report of
>>>> it already producing ³instant results² for his project in Stanislaus County
>>>> supports that notion, and is both welcome and frightening.
>>>>  
>>>>  Finally, I want to acknowledge David Eisenberg and Matts Myhrman who
>>>> together forged the first SB code in Arizona in the early-mid 1990¹s, and
>>>> to David again for speaking so convincingly on behalf of the current
>>>> proposed code at the recent hearing in Chicago.  If you read his
>>>> description of what he said, you¹ll see that he simply told the compelling
>>>> truth about the most relevant issues.  It¹s one of many things David does
>>>> so well.  It¹s nice when the compelling truth prevails (at least for now).
>>>>  
>>>>  Thanks David, and thanks to all.  And thanks to the enduring spirit of
>>>> strawbale!
>>>>  
>>>>  Martin
>>>>  
>>>>  PS - For a pre-IGCC history of this SB code, see my GSBN post on Dec. 1,
>>>> 2009.  Reviewing that e-mail might also be used as a natural aid to help
>>>> you fall asleep.  However, for me it is a riveting drama (sometimes moving
>>>> at the pace of a melting glacier . . . actually that¹s happening quite
>>>> quickly these days!)
>>>>  
>>>>  
>>>>  
>>>>  
>>>>  On 8/16/10 10:13 PM, "strawnet at aol.com" <strawnet at aol.com> wrote:
>>>>  
>>>>  
>>>>>  Hello all,
>>>>>  
>>>>>  I want share some great news. Earlier today, here in Chicago, Martin
>>>>> Hammer's "comment"/proposal to include the strawbale code he¹s been
>>>>> working on over the past few years in California into the new
>>>>> International Green Construction Code (IgCC) was approved by a committee
>>>>> vote of 8 to 6! The IgCC is the new US code for commercial (and high-rise
>>>>> residential) buildings that will become part of the family of 2012
>>>>> International Codes (I-codes). It will go through a full code development
>>>>> cycIe with the rest of the 2012 I-codes next year and there is work that
>>>>> will need to be done still to make sure it doesn¹t get rejected in that
>>>>> process, but getting it into the second public draft of the code now is a
>>>>> very big step forward.
>>>>>   
>>>>>  I served on the drafting committee for this code from last summer through
>>>>> the spring of this year. For more information about the IgCC and to
>>>>> download the whole IgCC first public draft and the comments  including
>>>>> Martin¹s proposals for strawbale and earthen building and the EcoNest
>>>>> comment in support of straw clay go here:
>>>>>  http://www.iccsafe.org/cs/IGCC/Pages/default.aspx
>>>>>  http://www.iccsafe.org/CS/IGCC/Pages/Comments0810.aspx
>>>>>  You¹ll find these listed as comments 5-134, 5-135 and 5-136.
>>>>>  
>>>>>  I was the only proponent speaking in favor of it here, and there were
>>>>> others who spoke in opposition. The initial motion was to disapprove but
>>>>> it failed 5 votes to 9 after considerable and very mixed discussion 
>>>>> which surprised me because of the nature of some of the comments  that it
>>>>> was still not ready and needed some technical fixes.
>>>>>   
>>>>>  The failure of the motion to disapprove required a new motion and Chris
>>>>> Mathis, an old building science friend from North Carolina, offered a
>>>>> motion for approval. That was followed by more discussion, with more
>>>>> concerns expressed that it wasn't ready. Then, just before the second
>>>>> vote, Chris pressed the committee to push the envelope. He said they
>>>>> should approve it and get it in, and rather than just having the few
>>>>> people who are very knowledgeable about it work on improving the things
>>>>> that still need to be done, ³Let thousands of people look at it and help
>>>>> improve it through the next round of the code development process!² He
>>>>> said it was time to start pushing these things through. Then they voted -
>>>>> and it passed 8 to 6! I was amazed and delighted! So it is going into the
>>>>> second public draft!
>>>>>   
>>>>>  There were two other similar proposals (they¹re called ³comments²) that
>>>>> were heard right before the strawbale comment. The first, from Paula Baker
>>>>> Laport and Robert Laport proposed including the straw clay guidelines from
>>>>> New Mexico. Next was the other submitted by Martin, that one in support of
>>>>> earthen construction based on the new ASTM standard for earthen wall
>>>>> systems that I had initiated almost 10 years ago and Bruce King has
>>>>> spearheaded over the past few years. I spoke in support of both, but they
>>>>> were disapproved, though both received encouraging suggestions to bring
>>>>> them forward again after addressing non-mandatory/permissive language and
>>>>> other issues.
>>>>>   
>>>>>  Because they were heard one after the other, and I was the only proponent
>>>>> for them, I got to speak first for each one and so I had a total of 6
>>>>> minutes (2 minutes each) to frame them all in terms of the big issues I¹ve
>>>>> been speaking to for all these years, including the coming challenges of
>>>>> ever-more limited and expensive energy, the low-impact, low-tech, climate
>>>>> beneficial, local/regional benefits, the industrial/proprietary bias and
>>>>> difficulty in funding research, testing and development for public domain,
>>>>> non-proprietary materials and systems. I started off by talking about the
>>>>> fact that I had been in buildings in Europe built with materials like
>>>>> straw clay and earth that are twice as old as this country! And to say
>>>>> that these are durable and safe ways of building when done properly. And
>>>>> when talking about the ASTM earthen standard, I said that if they looked
>>>>> at it they might think that it was too low tech to be reasonable compared
>>>>> to the standards that they¹re used to for concrete and other industrial
>>>>> materials. But, I said, It was intentionally low tech. That I was involved
>>>>> in initiating that standard almost ten years ago and it was both to enable
>>>>> the use of those materials here and to reverse the outlawing of earthen
>>>>> building in developing countries through the adoption of modern industrial
>>>>> codes. That it was designed to enable people to build safe, durable,
>>>>> healthy, and affordable buildings anywhere in the world‹including the in
>>>>> United States. I mentioned that the committee that developed that standard
>>>>> included the leading experts on earthen building and engineering from
>>>>> around the world and was based on reviewing and incorporating the best
>>>>> from international codes and standards for earthen building.
>>>>>   
>>>>>  After the first two went down, I was quite convinced because of the
>>>>> comments that the sb proposal would share the same fate and, thankfully, I
>>>>> was wrong!
>>>>>   
>>>>>  So hats off to Martin, Bruce, Matts, and many others who have worked so
>>>>> long and hard to develop these codes and to Chris Mathis for his
>>>>> leadership and visionary action on the committee.
>>>>>   
>>>>>  Onward!
>>>>>   
>>>>>  David Eisenberg
>>>>>  
>>>>>  
>>>>> 
>>>>> _______________________________________________
>>>>>  GSBN mailing list
>>>>>  GSBN at greenbuilder.com
>>>>>  http://greenbuilder.com/mailman/listinfo/GSBN
>>>>>  
>>>> 
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