[Cob] Windows in Cob Wall

[Bill Wright, L.Ac., DNBAO]

Hi Shannon, 

Thanks so much for your response! You answered my basic question with
your statement, "Just cob, with or without plaster around your windows
should be fine". And yes your assumption about cob on the interior of
the windows is correct; keeping the glass snug against the exterior cob.


I'm not totally clear about your statement, "Caulking or other sealants
would be useless as the water will come in around it through the
plaster". It's confusing to me because the outside of the building has a
lime render over the cob. I understand that lime, "breathes", but I
understand that it also acts to keep water out for the most part;
functioning more to allow the transpiration of water, and not the actual
transportation of water. Is this your understanding/experience?

thanks again for your help! 

Bill

---
Bill Wright, L.Ac., DNBAO

Wright Acupuncture and Massage

251 Auburn Ravine Rd., Ste. # 205

Auburn, CA 95603

530-886-8927

http://www.auburnacupuncture.net

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On 2016-10-04 19:33, Shannon Dealy wrote:

> Hi Bill,
> 
>> https://www.dropbox.com/sh/1qdluvmacdbtwzk/AAB0P4NasiZOEXS9wT59u26ha?dl=0
> [snip] 
> 
>> It's the exterior lime to glass connection that I'm concerned about. My
>> plan was to put a bead of silicone caulking at that joint to seal out
> [snip]
> 
> Having looked at the pictures, I see nothing obvious that would be a problem. Caulking or other sealants would be useless as the water will come in around it through the plaster. Just cob, with or without plaster around your windows should be fine. The only real concern with any cobbed-in window is across the bottom where it needs to have a reasonable slope to prevent any standing water.
> 
> I am assuming here that the interior of the glass will also be cobbed over to some degree matching the exterior, which should keep it snug against the exterior cob.
> 
>> The panes were installed, and in place and during the interior
>> plastering process BOTH of them were shattered (pic of that included
>> too). So I'm taking this OPPORTUNITY to cry A LOT. . . I mean, to pause
>> and reassess, and email you.
> 
> Can't really tell why/how the wire lath is being used, or why your windows shattered. The usual reason is too tight a fit so that the edges of the glass become load bearing (never good). Possibly your wood frame is too snug to the glass and when you plastered, the moisture expanded the cob, pushing the frame into the edges of the glass. The frame does not look particularly strong. This is not necessarily a problem, as bare glass can be directly embedded in cob, however, you have to adapt your building technique to make sure that the load on the glass is relatively low by building slowly and being very careful of the load at the top.
> 
> I once built a 6' x 2.5' piece of bare glass into a wall (single pane) with no framework around it, only a chunk of wood directly overhead embedded in the top of the wall. It wasn't until I reached the 5' level that I discovered it wasn't tempered glass (old window pane someone gave me) and the glass cracked. As it wasn't tempered, the pane was weaker and I built a little too fast for it. Fortunately, not being tempered, it didn't break into a million pieces and is still in that wall almost 10 years later with no additional cracking.
> 
> NOTE: this is bare cob around the window which faces into the wind in a wet climate (~40" rain/year).
> 
> The point is that what you are trying to do is certainly possible in cob without sealants.
> 
>> I am thinking of a complete re-design if y'all think I should abandon my
>> current design, OR I'm thinking of squirting a bunch of roofing tar
>> along the edge of the glass and squishing it into the framing so it
>> squirts out the edge on the exterior where the stucco meets the glass;
>> thus creating a seal.
> 
> I dont see any reason not to replace the glass and continue (though I might just do one side at a time. I would pay particular attention to the top and sides of the wood frame around the window while plastering to see
> if they are pushing into the sides of the window. My only real concern is how much load is placed on the window and how much load is on the cob around the window which I really can't tell from the pictures.
> 
> Shannon C. Dealy            |         DeaTech Research Inc.
> dealy at deatech.com           | - Biotechnology Development Services -
> Telephone:  +1 541-929-4089 |        USA and the Netherlands
> USA toll free: 800-467-5820 |            www.deatech.com [1]
 

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