Firebox decision for build

[Poppy65]

I'm having a new trailer smoker built and I'm stuck on choosing a 1/2 inch all around square firebox or 1/4 inch (air gap) insulated square firebox. Putting a warmer on top with a damper in between to use for smaller cooks. The box would be a 24x24x24. Any suggestions or concerns you could throw my way would be greatly appreciated.

 

[pjtexas1]

I wouldn't go air gap, might as well insulate if you have 2 walls unless I'm missing something.

 

[SmittyJonz]

I'd do 1/4" with mineral wool or rock wool insulation.

 

[Doug Crann]

Bag of Rockwood from Home Depot is like $40.

 

[TuscaloosaQ]

Of the 2 choices you gave... I would go 1/2 inch....v/s the air gap.. Simply for longevity!!!!