[Cob] Re: cob domes?

[dirtcheapbuilder-Charmaine Taylor]

Hi--it is not old and it was not cob. It was  Owner Built Home book  
author Ken Kern--  a cement arch cracked, and the earth bermed wall   
above was heavy and fell on him.

Not an urban legend, I posted this info just 2 years ago.. somewhat  
quietly...   the rainstorm part is true.

He was not normally out there in an unfinsihed structure, but this was  
bad timing & very bad luck  all around.

People kept saying "look at what happened to Ken Kern he ( as in "not  
safe")   got killed by his own house"  which was not true..so I tried  
to correct it. prolly made it worse if what you just wrote is what  
people now think.

Charmaine




On May 14, 2005, at 7:53 AM, Raduazo at aol.com wrote:

>
> Nearly everyone has heard the story about the man who built a cob dome  
>  and
> was killed in his sleep during a heavy rainstorm. The story is so old  
> and so
> oft repeated that it has reached the status of urban legend. I would  
> like to
> know if anyone has seen pictures of the collapsed dome or has first  
> hand
> knowledge from seeing the dome after its collapse?
> My reason for asking this is that I have a theory regarding cob domes.  
>  The
> problem with a cob dome is that at the peak of the dome the surface is  
>  nearly
> horizontal. This means that water and snow will set on this mostly   
> horizontal
> surface for long periods of time and soak in, and when the dome   
> collapses it
> will be only the horizontal center that  collapses.
> If this is the case then that problem has been solved both by the  
> onion  dome
> shape of Moscow and by US patent 4665664 to Brian Knight.
> I met Mr. Knight more than 20  years ago when he came down to my  
> office from
> Canadian. It seems that shingles  do not do well on an almost  
> horizontal
> surface because ice dams cause water to  back up under the shingles  
> and even light
> breezes can cause water to flow gently  up hill under the shingles and  
> into a
> dome. Mr. Knight’s solution was to change  the slope in such a way as  
> to
> depart from the dome shape as it approached the  peak of the structure.
> We cannot send pictures over the cob net but you might be able to get  
> a  copy
> from
> _http://164.195.100.11/netacgi/nph-Parser?Sect1=PTO2&Sect2=HITOFF&u=/ 
> netahtml/
> search- 
> adv.htm&r=7&p=1&f=G&l=50&d=ptxt&S1=4665664&OS=4665664&RS=4665664_
> (http://164.195.100.11/netacgi/nph-Parser?Sect1=PTO2&Sect2=HITOFF&u=/ 
> netahtml/searc
> h-adv.htm&r=7&p=1&f=G&l=50&d=ptxt&S1=4665664&OS=4665664&RS=4665664)
> You need special software  to see and print the pictures. I can send a
> photograph to anyone interested, but  residents of North America will  
> recognize this
> structure as the domes erected by  the highway departments of  Canada   
> and
> the US to store salt and sand for use during the winter.
> Besides the shape of the dome we can also encourage water to move on  
> down
> the trail by making the dome surface very smooth and treating it with a
> hydrophobic material like boiled linseed oil.
> So far I have tried this only on birdhouses, but I am thinking of  
> moving  up
> to small shed in size. I like the idea of small structures that cost  
> nearly
> nothing. The problem that you run into (in spades of course) is the  
> square cube
>  ratio. The strength of a material goes up as the square of a  
> dimension but
> the  weight goes up as the cube of that dimension. In other words a  
> two-inch
> block of  dirt is four times as strong as a one-inch block of dirt but  
> eight
> times as  heavy.
> Hopefully a small shed will not be as heavy or as life threatening as  
> a  full
> sized structure, and it will not be occupied during rain storms, but if
> smaller structures work out who knows. A zero-cost waterproof roof  
> would be a
> nice thing if we could trust it.
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>
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