Farm WFO?

Well my own experience is with rebuilding silos, not new ovens (so take this with a large grain of salt); nevertheless I'll try:

If the chimney is higher than just a few feet, I think you're going to need some sort of inside/invisible framework to hold it up. (Like office buildings where the outside is a "curtain wall" -often of glass- and something else holds the building up.) Having the same thing do both the "hold it up" and the "make it work" functions sounds nice, but...  The only way I've seen it work is with really heavy gauge corrugated steel; even bricks have trouble (often the house helps hold chimneys upright, and they usually have a "flue pipe" -and sometimes even some metal- inside).

Here's one idea (probably not very good, but at least it's something): Maybe you can use the kind of reinforcing rod typically cast inside of concrete. (It's often called "rebar" for short, and since it's so widely used it's pretty cheap.) Pour a concrete foundation with the lowest level of rebar in that concrete while it's still wet. Tie them together with more bars going around. Then add more bars to go up further. Tie all the bars together with heavy stainless steel wire (something that will support a lot of weight, and won't rust no matter what). When the framework is ready, wrap it with rounds of chicken wire and fasten each bit of chicken wire firmly to the rebar. Then finally spray your surface material onto the chicken wire.

A WFO chimney may have to be a smaller diameter and shorter to draft right. You may want to build a regular WFO chimney inside the decorative silo.

Hi Faith here is a picture of our WFO, the chimney area is substantial  and goes through a roof covering, the smoke exits the baking/firing chamber through  the oven doorway, it would be realatively easy to fashion a decorative silo  for the smoke to exit trough to achieve the look you are seeking. As you can see the WFO has a steel roof covering on ours also and looks like an oversize dolls house to some.

regards Yozza

First, the silo -- yes,  you can do this and it's not too difficult. I'd do it with insulated flue pipe and just stucco the outside walls. You can use wire lath to get the necessary shape. Sorta like it's done on newer houses with non-masonry chimneys -- those are usually just wood frames surrounding an insulated metal flue. I'd probably just install a tee fitting at the top to divert the smoke to the sides, but you may have fire code issues to contend with requiring a spark arrestor at the top. Check that out before you commit to a plan.

Thermometer -- I got it on a web site specializing in Big Green Egg stuff. It's made to go in the lid of the BGE. Don't remember the site, but here's one: http://www.amazon.com/Tel-Tru-LT225R-Replacement-Thermometer-degrees/dp/B0055777EU/ref=sr_1_4?ie=UTF8&qid=1316084873&sr=8-4

 I used this particular one because: a) it goes up to 1,000 °; and b) it has a long probe (5", IIRC). I drilled a shallow hole in the door face to accept the face of the thermometer, and a small hole through the door and metal cladding on the inside to accept the probe. The whole thing is held in by a clip on the inside that came with the unit, seen here:

Hope that helps.

ClimbHi
Pittsburgh, PA