Started out with a 2"x4" frame.
Added plywood to the outside of the frame and then decided to add 1/2" Durock in the hear chamber. Although I am using 2 - 1500w electric burners for heat, I figured it was cheap insurance.
Next I sealed everything up with a fire-proof caulking generally used in the fire sprinkler industry. It provides an airtight environment.
Next was 1 1/2" insulation and installation of the rack trays. Racks are 12"x17" half-sheet baking trays.
Next was wrapping it all in plywood and cutting the vent holes. I went with 2 - 4" vents on opposite sides.
Next was the doors. The doors are insulated as well. I also put general use weather stripping around both doors. The bottom door also has Durock on it.
Next was the roof, which was also insulated. I went with a single 4" exhaust made out of aluminum. The top is galvanized and there is a 4" butterfly damper installed inside. I am planning on putting shingles on top next.
And finally a shot of the racks, burners, and square cast iron skillets that will hold the wood chips. Only thing left to do now is paint and put roofing on it. That should happen in the next couple days, then I will crank it up and see how see does. I am happy with the progress and will keep updating how it goes. Thanks for looking.