[Cob] Weatherproofing a cob bench

[Ocean Liff-Anderson]

A real problem you're going to have in Ithaca (that they don't have  
in Oakland) is that any moisture which inevitably penetrates the cob  
will likely freeze and cause the plaster to fail, flaking off.  Only  
a completely water proof seal would prevent this, but then this would  
compromise the cob which needs to breathe.

I think the best thing is a waterproof roof or a very good tarp, with  
room for ventilation (tarps can also trap condensation underneath if  
they don't have ventilation).

Do you have a picture of the bench?  I would love to see it!

Peace,
Ocean Liff-Anderson
www.fireworksvenue.com
www.peacemaking.org


On Dec 17, 2008, at 11:01 AM, Terra Incognita wrote:

> Brina,
>
>
>
> There's an uncovered cob bench at the Merritt College landscape
> horticulture building in Oakland CA. I don't know how long it has been
> like that or how it's held up/been maintained. I should figure out how
> to contact them...
>
>
>
> I really like how your bench has the roof supports incorporated right
> into the body of the bench. Since I've already built this one, that's
> not an option.
>
>
>
> thanks,
>
> ~Dirk
>
> --- On Tue, 12/16/08, yewberry at wavecable.com  
> <yewberry at wavecable.com> wrote:
> From: yewberry at wavecable.com <yewberry at wavecable.com>
> Subject: Re: [Cob] Weatherproofing a cob bench
> To: nomadbuzzahd at yahoo.com, coblist at deatech.com
> Date: Tuesday, December 16, 2008, 2:56 PM
>
> Terra Incognita wrote:
>
>> I've seen uncovered cob benches elsewhere.
>
> Where?  And do you know if they held up long-term?
>
>> Is a lime plaster my best bet or are there other options?
>
> Lime is water permeable if water is left to sit on it (in the case  
> of a
> horizontal surface, like a bench seat).  I can't think of any natural,
> waterproof coating that will hold up to the elements for more than  
> a season in
> most of the Continental U.S.  You might have luck with a beeswax/ 
> linseed combo,
> but I'm guessing you'll have to renew the finish every year.
>
> Cob simply doesn't perform well without a roof.  Any chance you  
> could build
> one into the bench (instead of making it free-standing)?  That's  
> what we did
> with ours, and it's holding up well:
>
> http://home.wavecable.com/~yewberry/cobbers/back8-4-06.jpg
>
> Brina
>
>
>
>
>
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