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Hi all,
We still precompress the walls, however we do not use threaded rod, wire
or plastic strapping. The manufacturers of the plastic strapping advised
me that it cannot be tensioned more than once, as the crease created by
the initial tensioning will be a point of failure. We have opted for a
19mm flat polyester strapping which has a breaking strain of 1,100
kilograms. It is joined with extra heavy duty metal buckles which we fit
to each side of the wall. The strapping is fitted under the timber
bottom boxing, and does not require any protection. It is great for
earthen render, however it is susceptible to high alkaline exposure, so
it would be unadvisable to use for lime render.

We compress both infill and load bearing with this method. We achieve
about 7% compression with good bales. Because we are using polyester,
which can be retensioned over and over, we retension 3 times to achieve
the 7%.  Using this compression system our walls are sufficiently stable
to eliminate the need for bracing the posts and beams of infill
construction. Thus yet another way to eliminate steel in the form of
braces from the walls.

I spoke with Dr John Zhang some months ago about compression, and was
somewhat surprised to hear that they have been using the same system
successfully for a number of years.

It is quick, strong, inexpensive compared to wire with gripples or metal
thread, and it is much safer to use than wire safe. Lumleys insurance
informed me that the claims they have had for fire with straw bale
construction are all related to steel fabrication on site. Either
welders or angle grinders to cut metal thread. This I believe is another
good reason to keep steel out of the building wherever possible, to say
nothing of the ecological issues related to steel.

Full details of this method are in my book which I am pleased to say is
now available.

Kind regards
Brian Hodge

-----Original Message-----
From: GSBN [<a  target="_blank" href="mailto:GSBN@...";>mailto:GSBN@...]
Sent: Wednesday, 23 August 2006 8:06 AM

Date: Tue, 22 Aug 2006 16:35:27 -0500
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Subject: Re: GSBN:Compression &amp; bumble bees
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At 6:34 AM +1000 8/23/06, John Glassford wrote:
>Having completed the pre-compression we now lock the top plates in with
>all thread in fact we use all thread for all our pre-compression. I do
>not like the fencing wire and gripples as they do not give a very
>accurate finished top plate AND the gripples eventually give and the
>wires get loose.

I'm surprised to hear that anyone is still using all thread.  Are you
impaling the bales on them as was done 12-14 years ago, or have you come
up with some easier method? (I hope)

Have you tried any of the pallet-strapping techniques?  Or does the use
of plastic bother you too much to do that?

Bill Christensen
<<a  target="_blank" href="http://sustainablesources.com/contact/";>http://sustainablesources.com/contact/</a>>

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