[GSBN] SB Overhangs (was Big News!)
martin hammer
mfhammer at pacbell.net
Fri Sep 17 12:15:57 UTC 2010
Thanks for your input Sarah. I will e-mail you the proposed code off-list.
Martin Hammer
On 9/17/10 3:01 AM, "Sarah Johnston" <sarahjohnston at ihug.co.nz> wrote:
> Hello all.
>
> We agree that eaves are very important and also feel there should be a minimum
> eave depth included for a SB code, the difficult part is making it appropriate
> for all climates.
>
> With our experiences with projects in dry, windy parts of NZ we do disagree
> with the concept of making the eaves oversized in the code then have industry
> professionals argue to have smaller eaves if they wish. This approach creates
> a challenging situation for design professionals and code officials who end up
> having to put themselves in a vulnerable place from a liability perspective
> just to get to a realistic eave depth for the climate they are working in.
> This approach creates a lot of extra work as well.
>
> A BIG congratulations for all your great work and thanks to everyone involved
> in the code effort! We would most certainly appreciate a copy of the present
> draft code to have a look at.
>
> Warm Regards,
> Sarah & Sven Johnston
>
> Sarah Johnston
> Sol Design, Ltd.
> 50A Connolly Street
> Geraldine New Zealand
> 03 693 7369
> sarahjohnston at ihug.co.nz
>
> On Sep 1, 2010, at 11:53 PM Sep 1, 2010, Graeme North wrote:
>
>> There are many ways to give a strawbale wall primary weather protection - the
>> trick is to make sure that it happens, and this is what a Standard can do.
>> Rain screening of some sort is one wonderful method.
>>
>> What I despair of is designers who appear to think that they are "getting
>> away" with something (what?) by leaving good prudent primary weather
>> protection off their buildings.
>>
>> I prefer to sleep on wet windy stormy nights.
>>
>>
>>
>>
>> Graeme
>> Graeme North Architects
>> 49 Matthew Road
>> RD1
>> Warkworth
>> tel/fax +64 (0)9 4259305
>>
>> graeme at ecodesign.co.nz
>> www.ecodesign.co.nz <http://www.ecodesign.co.nz>
>>
>>
>>
>> On 1/09/2010, at 11:52 PM, Rikki Nitzkin wrote:
>>
>>> Hi all,
>>>
>>> Maybe this code could include various Options since there are many ways to
>>> solve the problem.
>>>
>>> About protecting clay-plastered walls from wind-driven rain or un protected
>>> gable roof walls, there is always the option of a ventilated rain-screen. I
>>> have seen many different options made with wood in Denmark, and on some of
>>> Tom Rijven's buildings in france. The rain -screens can be simple, beautiful
>>> and permit clay plaster.
>>>
>>> By the way, are you all aware of the Loadbearing Dome and Vault building
>>> (with a Green Roof) Gernot Minke is working on in Slovakia? It should be
>>> quite spectacular, and could make a nice article for TLS. I am off to
>>> participate in the build next week. Check out fotos at:
>>> http://minke-strawbaledome.blogspot.
>>> <http://minke-strawbaledome.blogspot.com/> com/
>>> <http://minke-strawbaledome.blogspot.com/>
>>>
>>> baling on...
>>>
>>> Rikki
>>>
>>>
>>>
>>>
>>>
>>>
>>> El 26/08/2010, a las 13:03, martin oehlmann escribió:
>>>
>>>> Hello all,
>>>>
>>>> again compliments to all this great work which in essence should make
>>>> things easier by systemized solutions. If I read Andys remarks on freedom
>>>> of desgin we might be able to solve the paradox of securing people from
>>>> design failures and at the same time stimulate ongoing experiments by a
>>>> simple preamble for codes: ."this or better".
>>>>
>>>> This would be an opening to convince building inspectors for what's not be
>>>> known yet, but definitly soon will be offered. Without flexibility there is
>>>> just little innovation. And it is the "cemented aspect" of the building
>>>> industry which spends a minimum for innovation in comparison to other
>>>> sectors.
>>>>
>>>> Best wishes from a rainy Brittany,
>>>>
>>>> Martin Oehlmann
>>>>
>>>>
>>>>
>>>>
>>>> ----- Original Message -----
>>>>> From: Andy Horn <mailto:andy at ecodesignarchitects.co.za>
>>>>> To: '(private, with public archives) Global Straw Building Network'
>>>>> <mailto:GSBN at greenbuilder.com>
>>>>> Sent: Wednesday, August 25, 2010 10:36 PM
>>>>> Subject: Re: [GSBN] SB Overhangs (was Big News!)
>>>>>
>>>>> Hi Martin
>>>>> I certainly don¹t envy those trying to create a 1 size fits all
>>>>> international building code that balances freedom of design and place for
>>>>> innovation with the specifics of good building practice. Anyhow to add
>>>>> some further food for thought.
>>>>>
>>>>> In answering questions about what to do with multi storey designs, I
>>>>> always find history to be such a valuable tool when it comes to looking at
>>>>> various design responses.
>>>>> The vernacular architecture of Japan has evolved a very sensible
>>>>> architectural style when it comes to protecting their thin little earth
>>>>> plastered wattle and daub structures. Numerous numbers of these structures
>>>>> still exist with some are many hundreds of years old, with some being even
>>>>> 3 or 4 storeys high of earth plaster!! The roofs are often but not always
>>>>> hipped, affording good overhangs all around and in the case of multi
>>>>> storey buildings each floor has its own min roof around it like skirts.Šso
>>>>> shedding the rain at each level. In the case of gabled wall ends, all the
>>>>> openings have min roofs over them. Other times the clay wattle and daub is
>>>>> given a basic plaster and then an external timber siding rather than more
>>>>> plaster is used. Effectively parapet walls are generally avoided so the
>>>>> roof always closes over the top of a wall. Even their boundary walls,
>>>>> which are usually of more solid packed earth and are typically earth
>>>>> plastered, all have mini roofs over the tops of the walls Š.usually 1
>>>>> layer of beautiful crafted fire clay tiles overhanging either side with a
>>>>> ridge cap in the centre. Their plastered walls are also broken into panels
>>>>> with expressed timber framing, so that the plaster surfaces are broken
>>>>> down into manageable sizes that can be plastered to absolute perfection
>>>>> and generally present much fewer problems with cracking.
>>>>>
>>>>> I am not familiar with the extent or wording of the code, so I may be
>>>>> speaking out of context but generally I would be worried about being
>>>>> overly prescriptive about how one solves a problem ....especially where
>>>>> officials can take a narrow interpretation of a code and there may be ways
>>>>> and new products that have not been thought of yet that may offer
>>>>> alternate solutions? While I agree having roof overhangs is best practice
>>>>> and I have not done otherwise, it may be wiser that one set about defining
>>>>> what one is trying to do that a roof overhang is doingŠi.e. not letting
>>>>> water get in from the top being the most critical clearlyŠ.. or is one
>>>>> trying to give the wall some degree of protection from rain hitting it by
>>>>> using an overhang as well? Because outright protection I don¹t believe is
>>>>> practical or even necessary. I think the degree or amount of overhang is
>>>>> more of a regional thing that is even specific to the exact context of the
>>>>> site of the buildingŠ the intensity of rain that is potentially hitting a
>>>>> wall and the direction that it comes (rain does not always come from
>>>>> above) are clearly important factors to try and understand and respond to
>>>>> and will vary from place to place.
>>>>>
>>>>> Context will change things and how one designs in relation to the context
>>>>> Š..so I would imagine some of what the code needs to address would be how
>>>>> design may respond differently in relation to the amount of rain, wind
>>>>> direction, wind driven rain (if applicable), rain intensity, when it rains
>>>>> in relation to how cold or hot it is, so one understands how quickly or
>>>>> otherwise rain may be able to dry out again. The position of ones
>>>>> overhangs and rain buffers (pergolas, shade devices etc) and use of rain
>>>>> screens may be of more importance depending on where and how big one
>>>>> designingŠŠthe rain here in the Cape is typically winter rainfall that is
>>>>> wind driven almost always coming from the North westŠ.and in some cases
>>>>> comes in horizontally especially along the coast. In these cases one has
>>>>> to look at incorporating siding over the bales and rain screens on the
>>>>> exposed sides to help shield the rainŠ.and in certain cases I will avoid
>>>>> using straw in the parts where it is too at riskŠ.so I rarely end up with
>>>>> a building with 100% of its walls being in straw bale.
>>>>>
>>>>> Best
>>>>> Andy Horn
>>>>>
>>>>> ECO DESIGN Architects & Consulatants
>>>>> 6th floor, 79 on Roeland, 79 Roeland St.
>>>>> 8001, CAPE TOWN, SOUTH AFRICA
>>>>> Tel: 07 21 462 1614, fax 07 21 461 3198
>>>>> website: www.ecodesignarchitects.co.za
>>>>> <http://www.ecodesignarchitects.co.za>
>>>>>
>>>>>
>>>>>
>>>>> From: GSBN-bounces at greenbuilder.com [mailto:GSBN-bounces at greenbuilder.com]
>>>>> On Behalf Of martin hammer
>>>>> Sent: 25 August 2010 02:50 PM
>>>>> To: (private, with public archives) Global Straw Building Network
>>>>> Subject: Re: [GSBN] SB Overhangs (was Big News!)
>>>>>
>>>>> 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 <http://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
>>>>> fromNew 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
>
>
>
>
>
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