[GSBN] CMHC Straw Light Clay Report (was Light Straw fire test?), and Codes

[Derek Roff]

It's great to have this report.  I wonder if others share my concern about the thermal conductivity figures.  Samples A3 and B3 differ in density by 5%, while their R-values differ by 110%, with the slightly higher density sample having the higher R-value.  The U-values vary by 119%, which may indicate rounding error.  Other samples also show variation large variation in thermal conductivity.  We always need more and better testing for everything, but this level of variation is a bit oversized to use as a basis for code standards, it seems to me.  Of course, we could do what the drug companies do, and just discard the inconvenient data.  I'm glad that didn't happen in this report.  

Derelict

Derek Roff
derek at unm.edu

On Nov 11, 2011, at 11:28 PM, martin hammer wrote:

> Thanks David for the link.
> 
> A note of clarification.  Although the subject line was initially “Light Straw Fire Test”, the Research Report is about straw light clay in general.  This includes issues of thermal resistance, vapor permeability, moisture storage, compression, settling, density, and fire.  I believe it is the best document available regarding the technical aspects of straw light clay (also known as light straw clay, light clay, clay-straw, clay-fiber, straw-clay).  It may be the only document.  If anyone knows of another that examines the technical aspects of this system of construction please let me know.
> 
> I bring this up in the context of straw-clay and building codes.  Last week I spoke with Paula Baker-Laporte, an architect and leading practitioner (along with her husband and builder Robert Laporte) of “light clay” construction in the US.  In 2010 I reworked with Paula the New Mexico Clay Straw Guidelines, and she submitted them for inclusion in the IGCC.  Unfortunately they didn’t make the first hurdle.  What did happen was that Paula submitted the Guidelines to the City of Portland, Oregon where they were codified in February 2011.  She went on to propose the guidelines to the State of Oregon, where they are being considered for inclusion in its state building code (Oregon is also one of only three US states with a statewide straw bale building code).
> 
> Paula and I agreed Wednesday that we will submit a further developed version of the guidelines, with as much supporting documentation as possible, for inclusion in the International Building Code.  Because it is a non-structural system, we anticipate less resistance than I expect for straw bale.  Although I’m sure insulation manufacturers will be out in force. 
> 
> This brings me to my last point that I will continue in a subsequent e-mail . . . . .
> 
> Martin Hammer
> 
> 
> 
> On 11/11/11 4:54 PM, "David Eisenberg" <strawnet at aol.com> wrote:
> 
>> Hi all,
>> 
>> I just took the liberty of uploading the file Martin sent me via YouSendIt and made it available for download from this link:
>> https://rcpt.yousendit.com/1283271062/f834de86f87f727a5a4067a5a126a7e2
>> 
>> So you won't need to bother Martin in order to get a copy, and this file doesn't have an expiration date so you should be able to download it in the future. 
>> 
>> David Eisenberg
>>  





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