Finally ready to pour the throat and cut the smoke chamber. Here are a few pics of what I am planning to do--unless you tell me otherwise.

I have a 42" Rumford fireplace, so I needed a pretty big smoke chamber. Cutting the clay flue the way most people have for their chimneys wouldn't work for me because it would be too narrow for what I need, so I think that this 3-way cut will work nicely. It is a 13x18 liner, and cutting it this way (I do have another one that is to be cut with the mirror-image of the attached template) will give me about a 35ish" wide base.

Also, for the throat, I have laid the lath down over a plywood form and am planning to lay split-cut firebricks with refractory mortar, then pouring cement over that with a rebar grid.

I am planning to work on this late this afternoon or tomorrow (depending on how long the insulation work on the dome takes me), so please let me know your thoughts.

Thanks a million!

Claire