[GSBN] prefab strawbale - pinning

Andy Horn andy at ecodesignarchitects.co.za
Sat Aug 1 13:57:36 CDT 2009

Despite some fearsome winds here in Cape Town, our weather is generally a
lot kinder than in England and Canada's I would assume, where you would
rather be active inside for most of the year.

So not to judge but I would agree that pre-fab is 99% of the time going to
be a much higher embodied energy that building on site. With all our straw
bale projects we have always sourced our clay and our sand from very
close/closest to the site and half the time directly from the site itself,
so I would say the transport factor would increase heavily in pre-fab
scenarios. Also the size of the components/modules would mean specialized
heavy duty kind of transport with large bed and crane etc. 

On another tack Bale dipping is a kind of prefabrication
Itemid=44&g2_itemId=2406)....in that the initial clay soil plaster key is
done on the ground with the plaster side lying flat. Just before the dip
coat starts to dry, one reassembles the bales in between a frame, so that by
the time the bales are up again they are practically plastered. The finish
coats are simplified and walls rock solid. 

It was mentioned that the Balers in the US no longer bother pinning their
bales unless a building code necessitates it. Are you no longer fining it
necessary to pin because you are doing structural mesh reinforced plasters
and find it unnecessary...or because you are doing a lot of load bearing
with heavy strapping so find it not necessary?

We still pin our bales, though not from the bottom any more as this is in my
opinion/experience unnecessary and I would say indeed unwise as it can only
encourage condensation.

Andy Horn

-----Original Message-----
From: GSBN-bounces at greenbuilder.com [mailto:GSBN-bounces at greenbuilder.com]
On Behalf Of Derek Roff
Sent: 31 July 2009 10:43 PM
To: (private, with public archives) Global Straw Building Network
Subject: Re: [GSBN] prefab strawbale

--On Thursday, July 30, 2009 7:09 AM -0400 cmagwood at kos.net wrote:

> In terms of transportation... all the bales, lumber, sand and masonry
> ingredients get shipped from a source to a job site. Whether those
> materials come to the "factory" first, get assembled and then
> continue on to the job site seems pretty minor.

I think what you are doing is great, Chris, but I contest your 
statement above on transportation.  When materials are shipped first to 
a factory that is independent of the job site, the metaphor of the 
materials "continuing on to the job site" is misleading.  Each case 
would be different, depending on the locations of the sources, the 
factory, and the job site.  But doubling the amount of embodied energy 
due to transportation, loading and unloading, is a good average guess. 
And Bruce King recently reported that the proportional embodied energy 
of moving dense materials like earth, concrete, and sand, is very 

Having the factory at the job site, as you mention, avoids this extra 
embodied energy.  I am eager to learn more about your methods.


Derek Roff
Language Learning Center
Ortega Hall 129, MSC03-2100
University of New Mexico
Albuquerque, NM 87131-0001
505/277-7368, fax 505/277-3885
Internet: derek at unm.edu

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