[Cob] Windows in Cob Wall - WITH Pics URL

[Shannon Dealy]

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