[Cob] Coblist Digest, Vol 10, Issue 38

[Jac]

Having also demolished most of a redesigned cottage, built by fresh interns who had no experience, i can honestly say cob is tough, and straw does help. Namely one section we managed to sledge to head height but had a 3 or 4 foot protrusion holding fast above our heads, without any support but the Tensile strength of the straw and the integral strength of the aggregate. after soaking, it still required enormous amounts of enertgy to demolish.

Jacques


On May 23, 2012, at 4:00 PM, coblist-request at deatech.com wrote:

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> Today's Topics:
> 
>   1. Re: reinforcement (Ocean Liff-Anderson)
>   2. Re: Coblist Digest, Vol 10, Issue 37 (Monica Proulx)
>   3. Re: reinforcement (Jill Hogan)
>   4. Re: Coblist Digest, Vol 10, Issue 37 (Rhys Dyer)
> 
> 
> ----------------------------------------------------------------------
> 
> Message: 1
> Date: Tue, 22 May 2012 10:46:29 -0700
> From: Ocean Liff-Anderson <ocean at fireworksvenue.com>
> To: dhowell at pickensprogressonline.com, coblist at deatech.com
> Subject: Re: [Cob] reinforcement
> Message-ID: <A3B282E1-3A56-4458-9A33-07A744926B1B at fireworksvenue.com>
> Content-Type: text/plain; charset=US-ASCII; delsp=yes; format=flowed
> 
> So Damon, you've never demo'ed a cob wall?  Try it sometime, it is  
> instructive as to how strong the straw really makes the material.
> 
> You will find with your sledge hammer, or pick ax, or shovel, or  
> machete, whatever you try to smash it with, that cob will not come  
> off in any large chunks.  You are left scraping away small amounts at  
> a time.  The straw indeed keeps the material together, which is why  
> cob is earthquake resistant, holding together buildings for hundreds  
> or thousands of years.
> 
> Bamboo is great, but no substitute for properly mixed cob.  Lots of  
> straw, please!
> 
> 
> 
> 
> On May 22, 2012, at 9:19 AM, dhowell at pickensprogressonline.com wrote:
> 
>> I think bamboo would be a good route to go for reinforcement in  
>> sustainable building, because it is as strong as steel, they say,  
>> and it's a weed. Although I've heard some say the straw in cob acts  
>> as reinforcement, I don't think that is why they use it. It's more  
>> to keep the wet mix from slumping while the material is drying. But  
>> if I was to take a sledge hammer to a dry wall, I'm betting the  
>> straw isn't going to provide much resistance, but I could be wrong.  
>> It's worth trying. That's the kind of testing I have in mind.  
>> Numbers mean very little compared to real world, hands on tests  
>> like that. I have a cob storage shed I never finished that has a 3  
>> foot wall. I'm planning on tearing it down and I'll probably video  
>> myself doing it. That's real information!
>> Damon
>> 
>> _______________________________________________
>> Coblist mailing list
>> Coblist at deatech.com
>> http://www.deatech.com/mailman/listinfo/coblist
> 
> 
> 
> 
> ------------------------------
> 
> Message: 2
> Date: Tue, 22 May 2012 14:11:03 -0600
> From: Monica Proulx <mon.pro at gmail.com>
> To: coblist at deatech.com
> Subject: Re: [Cob] Coblist Digest, Vol 10, Issue 37
> Message-ID:
>    <CA+xEhQAQs9tuchaC1q3-QF1JVTRRKn=6qiexiDe2=uNLOZFysA at mail.gmail.com>
> Content-Type: text/plain; charset=ISO-8859-1
> 
> Reinforcement of cob with bamboo
> 
> 
> Damon,
> 
> The "improved Quincha" building techniques (earthquake resistant building
> method using cob in a wattle and daub application) being promoted in Peru
> and elsewhere by Practical Action encourage people to use bamboo when they
> can get it.  It's so flexible and strong.
> 
> I have a really good book on using bamboo in buildings, which also talks
> about how to treat it against insects though, (a problem in hot humid
> climates, probably still a potential problem even though bamboo is encased
> in adobe or cob?). Sounds like a bother to do, but worth investigating if
> someone is bent on bamboo in a termite prone zone.  I'm not sure if
> termites are as big a problem in the Pacific northwest as they are in the
> east and the south:  (Here's the bamboo book:  "Building with Bamboo: A
> Handbook.  by Jules J. A. Janssen, 1995, there are some copies on
> Amazon.com right now for around 16 dollars.)
> 
> Here's a great overview of Quincha building, search the webpage for
> "bamboo", it's mentioned several times.  There are also some great sketches
> you can zoom in on, which show how they are using it:
> 
> http://www.appropedia.org/Original:Earthquake-resistant_housing_%28Practical_Action_Brief%29
> 
> 
> 
>> Message: 2
>> Date: Tue, 22 May 2012 12:19:22 -0400
>> From: "dhowell at pickensprogressonline.com"
>>       <dhowell at pickensprogressonline.com>
>> To: coblist at deatech.com
>> Subject: [Cob] reinforcement
>> Message-ID:
>>       <4E1B92D4-DF77-486F-8E47-35E53CA9C9F8 at pickensprogressonline.com>
>> Content-Type: text/plain; charset=US-ASCII; delsp=yes; format=flowed
>> 
>> I think bamboo would be a good route to go for reinforcement in
>> sustainable building, because it is as strong as steel, they say, and
>> it's a weed. Although I've heard some say the straw in cob acts as
>> reinforcement, I don't think that is why they use it. It's more to
>> keep the wet mix from slumping while the material is drying. But if I
>> was to take a sledge hammer to a dry wall, I'm betting the straw
>> isn't going to provide much resistance, but I could be wrong. It's
>> worth trying. That's the kind of testing I have in mind. Numbers mean
>> very little compared to real world, hands on tests like that. I have
>> a cob storage shed I never finished that has a 3 foot wall. I'm
>> planning on tearing it down and I'll probably video myself doing it.
>> That's real information!
>> Damon
>> 
>> 
>> 
>> ------------------------------
>> 
>> _______________________________________________
>> Coblist mailing list
>> Coblist at deatech.com
>> http://www.deatech.com/mailman/listinfo/coblist
>> 
>> 
>> End of Coblist Digest, Vol 10, Issue 37
>> ***************************************
>> 
> 
> 
> ------------------------------
> 
> Message: 3
> Date: Mon, 21 May 2012 23:52:48 -0700
> From: Jill Hogan <info at mat.org.za>
> To: coblist at deatech.com
> Subject: Re: [Cob] reinforcement
> Message-ID: <4FBB37C0.9090907 at mat.org.za>
> Content-Type: text/plain; charset=ISO-8859-1; format=flowed
> 
> Yea I agree completely cob is unbelievably strong good luck Damon
> Jill
> 
> On 2012/05/22 10:46 AM, Ocean Liff-Anderson wrote:
>> So Damon, you've never demo'ed a cob wall?  Try it sometime, it is 
>> instructive as to how strong the straw really makes the material.
>> 
>> You will find with your sledge hammer, or pick ax, or shovel, or 
>> machete, whatever you try to smash it with, that cob will not come off 
>> in any large chunks.  You are left scraping away small amounts at a 
>> time.  The straw indeed keeps the material together, which is why cob 
>> is earthquake resistant, holding together buildings for hundreds or 
>> thousands of years.
>> 
>> Bamboo is great, but no substitute for properly mixed cob.  Lots of 
>> straw, please!
>> 
>> 
>> 
>> 
>> On May 22, 2012, at 9:19 AM, dhowell at pickensprogressonline.com wrote:
>> 
>>> I think bamboo would be a good route to go for reinforcement in 
>>> sustainable building, because it is as strong as steel, they say, and 
>>> it's a weed. Although I've heard some say the straw in cob acts as 
>>> reinforcement, I don't think that is why they use it. It's more to 
>>> keep the wet mix from slumping while the material is drying. But if I 
>>> was to take a sledge hammer to a dry wall, I'm betting the straw 
>>> isn't going to provide much resistance, but I could be wrong. It's 
>>> worth trying. That's the kind of testing I have in mind. Numbers mean 
>>> very little compared to real world, hands on tests like that. I have 
>>> a cob storage shed I never finished that has a 3 foot wall. I'm 
>>> planning on tearing it down and I'll probably video myself doing it. 
>>> That's real information!
>>> Damon
>>> 
>>> _______________________________________________
>>> Coblist mailing list
>>> Coblist at deatech.com
>>> http://www.deatech.com/mailman/listinfo/coblist
>> 
>> 
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>> 
> 
> 
> -- 
> McGregor Alternative Technology Center "MAT"
> Jill Hogan
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> ------------------------------
> 
> Message: 4
> Date: Wed, 23 May 2012 10:04:14 +1000
> From: Rhys Dyer <rhys_dyer at hotmail.com>
> To: <coblist at deatech.com>
> Subject: Re: [Cob] Coblist Digest, Vol 10, Issue 37
> Message-ID: <BLU159-W35512AD08638AF52D5EF268A030 at phx.gbl>
> Content-Type: text/plain; charset="iso-8859-1"
> 
> 
> --- SNIP>    1. Re: Fwd:  Fwd: cob shake test info (Henry Raduazo)
>>>> From: Shawn King <sbkingster at gmail.com>
>>>> Subject: Re: [Cob] Fwd: cob shake test info
> --- SNIP Excellent source. Thanks
> Rhys
>                           
> 
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> 
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> End of Coblist Digest, Vol 10, Issue 38
> ***************************************