[Cob] cob greenhouse question

[Malcolm Schluenderfritz]

Thanks for the advice. I guess then I will make the buttresses out of cob
and and bales separately for insulation.

Another question; The rubble trench, reinforced concrete bond beam and
urbanite stem wall for this structure have already been built. And since I
did not have buttresses in my original plan, they are not represented in
the foundation. Will they still work if I put in separate rubble trenches
and stem wall for them, since they will not be connected to the main wall
foundation?

Malcolm

On Thu, Sep 24, 2015 at 10:15 AM, john fordice <otherfish at comcast.net>
wrote:

> Mqlcome,
> Cob and strawbale walls act very differently to loads & while strawbale
> can be added over cob for insulation, I would not mix them structurally.
> Not a good idea.
> john
>
> On Sep 24, 2015, at 6:39 AM, Malcolm Schluenderfritz <
> mschluenderfritz at gmail.com> wrote:
>
> Hello John,
>
> Thanks again. One more question: could the buttresses be straw bale walls?
> I am thinking that the buttresses protruding from the back wall could be
> used as a chicken coop, which would benefit from heat from the cob wall,
> and insulate the greenhouse. I would already have three walls and the roof
> overhang.
>
> Yours,
> Malcolm
>
> On Wed, Sep 23, 2015 at 11:11 PM, john fordice <otherfish at comcast.net>
> wrote:
>
>> Hi Malcom,
>> Yes, the freestanding ends of your walls and midpoint of the long back
>> wall should still be buttressed.  I’d suggest putting the buttresses on the
>> outside surface of the walls & thus leave the rtransparent greenhouse walls
>> fully open to sunlight.
>> Small p[eces of urbanite should be ok, just don’t make them any bigger
>> than 2 - 3 “.
>> john
>>
>> On Sep 23, 2015, at 3:14 PM, Malcolm Schluenderfritz <
>> mschluenderfritz at gmail.com> wrote:
>>
>> Hello John,
>>
>> I modified the design. Now the tallest cob wall will be 6 feet. Do I
>> still need buttresses?
>>
>> I will leave out the urbanite chunks then. Would small pieces of rubble
>> less then two inches across be OK? I was wondering if they would act like
>> large gravel.
>>
>> Thanks for your help.
>>
>> Malcolm
>>
>> On Sat, Sep 19, 2015 at 10:18 PM, john fordice <otherfish at comcast.net>
>> wrote:
>>
>>> Malcome,
>>> A few suggestions relating to the cob:
>>> 1. Buttress the open ends of your rear & left end walls.  Make the
>>> buttress’s 3 or 4’ long at the stem wall & zero at the wall top.  Add an
>>> intermediate buttress at the midpoint of the rear wall.
>>> 2. Batter your walls to 12” thick at the top & 18” at the stem wall.
>>> 3. Do not put pieces of urbanite in the cob …… bad practice !
>>>
>>> This is relative to the cob only ……… the framing of the transparent
>>> materials support is another story …… sounds like the loads of the wood &
>>> plastic roof / walls will be minimal, so as long as you don’t have heavy
>>> concentrated loads either embed your rafters in the cob or add a top plate
>>> with deadmen in the wall.   Assuming you know how to make competent cob &
>>> build correctly ……… if not, get advice of an experienced cobber.
>>> john
>>>
>>> > On Sep 19, 2015, at 9:51 AM, Malcolm Schluenderfritz <
>>> mschluenderfritz at gmail.com> wrote:
>>> >
>>> > ---------- Forwarded message ----------
>>> > From: Malcolm Schluenderfritz <mschluenderfritz at gmail.com>
>>> > Date: Fri, Sep 18, 2015 at 8:40 PM
>>> > Subject: Re: [Cob] cob greenhouse question
>>> > To: Howard Switzer <howard at earthandstraw.com>
>>> >
>>> >
>>> > Hello Howard,
>>> >
>>> > Thanks for the advice.
>>> >
>>> > I will try to post a plan soon.
>>> >
>>> > I am stuck with the 18" base because the foundation is already build. I
>>> > agree that it seems something is needed at the North East corner.
>>> >
>>> > The concrete is to use it up and to speed drying on the wall. (An idea
>>> from
>>> > "The Hand Sculpted House." ) I got huge loads of broken concrete
>>> dumped for
>>> > the foundation and for retaining walls on other parts of the site.
>>> These
>>> > are pieces that are fairly good but not quite square enough for those
>>> uses.
>>> > Spaced widely (so that they do not form problematic joints) in the
>>> core of
>>> > the wall, it seems that they will allow me to use less cob, which not
>>> only
>>> > means faster drying, but also less cob mixing and less purchased sand
>>> use.
>>> >
>>> > I would think that if cob is strong enough to arch over small niches,
>>> it
>>> > would be strong enough to take a few pieces of concrete inside the
>>> wall.
>>> > But correct me if I am wrong.
>>> >
>>> >
>>> >
>>> > On Fri, Sep 18, 2015 at 8:29 PM, Howard Switzer <
>>> howard at earthandstraw.com>
>>> > wrote:
>>> >
>>> >> I know John will take good care of you, (do post your plan if you
>>> can) but
>>> >> basically you got a 16 foot wall braced on one end, right, so sounds
>>> like
>>> >> you need to brace the other end somehow. Now I expect there will be
>>> an east
>>> >> wall so you might consider bracing it in such a way as it could serve
>>> to
>>> >> buttress the end of the wall and you might want to embed some anchors
>>> in
>>> >> the cob for attaching that bracing wall....or you could just do a cob
>>> >> buttress off the end of the wall in the other direction, which is
>>> probably
>>> >> the better option, just guessing. You might also want to consider
>>> battering
>>> >> the wall a bit, wider (20") at the bottom than the top (16"), right?
>>> Might
>>> >> add some more stability. What are the concrete pieces doing in the
>>> middle
>>> >> of it?  Just trying to get rid of it or something?
>>> >>
>>> >>
>>> >>
>>> >> On Fri, Sep 18, 2015 at 2:31 PM, Malcolm Schluenderfritz <
>>> >> mschluenderfritz at gmail.com> wrote:
>>> >>
>>> >>> I am building a small greenhouse, 16 feet by 8 feet, and 8 feet
>>> tall. The
>>> >>> North and West walls will be cob, and about 18 inches thick. I will
>>> be
>>> >>> inserting some pieces of concrete as we go, in the center of the
>>> wall. The
>>> >>> walls are straight, not curved.
>>> >>> Do I need to add buttresses to this wall to keep it up, or is it
>>> thick
>>> >>> enough? The North and West walls already form a corner, so they
>>> provide at
>>> >>> least a little Lateral support to each other.
>>> >>> _______________________________________________
>>> >>> Coblist mailing list
>>> >>> Coblist at deatech.com
>>> >>> http://www.deatech.com/mailman/listinfo/coblist
>>> >>>
>>> >>
>>> >>
>>> >>
>>> >> --
>>> >> Howard Switzer - Architect
>>> >> 668 Hurricane Creek Road
>>> >> Linden, TN 37096
>>> >> 931 589 6513
>>> >> www.earthandstraw.com
>>> >>
>>> >> “You never change things by fighting the existing reality.
>>> >> To change something, build a new model that makes the existing model
>>> >> obsolete.”
>>> >> ― Richard Buckminster Fuller
>>> >> <
>>> http://www.goodreads.com/author/show/165737.Richard_Buckminster_Fuller>
>>> >>
>>> >
>>> >
>>> >
>>> >
>>> >
>>> >
>>> >
>>> > --
>>> > Malcolm Schluenderfritz
>>> > Secretary,
>>> >
>>> > The Saint Isidore Society,
>>> > saintisidoresociety.wordpress.com
>>> > _______________________________________________
>>> > Coblist mailing list
>>> > Coblist at deatech.com
>>> > http://www.deatech.com/mailman/listinfo/coblist
>>>
>>>
>>
>>
>> --
>> Malcolm Schluenderfritz
>> Secretary,
>>
>> The Saint Isidore Society,
>> saintisidoresociety.wordpress.com
>>
>>
>>
>
>
> --
> Malcolm Schluenderfritz
> Secretary,
>
> The Saint Isidore Society,
> saintisidoresociety.wordpress.com
>
>
>


-- 
Malcolm Schluenderfritz
Secretary,

The Saint Isidore Society,
saintisidoresociety.wordpress.com