June 1, 2014 - 3:39am
Confusion about floor of cob oven
I would like to build a cob oven and have watched and read about several methods of doing it. One method said you have to build it on top of a bunch of empty wine bottles so that the floor of the oven doesn't steal the heat. Where as other methods build it right on the ground. Wouldn't building an oven first over bricks/stones or on the ground steal the heat from the oven? I am just curious why other methods haven't mentioned the wine bottles.
Building the oven with the hearth floor directly on the ground or other solid masonry will require longer heating and also quicker dissipation of the heat in the floor. Using wine bottles, cellular glass (foamglas), or a mix with vermiculite in it. You could even use a mix of cobb and straw. Insulate the oven, its one thing you cant over-do.
I built an adobe oven from traditional New Mexican 'plans'. When I make my next oven it will be elevated to make it easier to use, heavily insulated, and with a fire brick floor instead of adobe plaster. Of course, I found Kiko Denzer's book after I built it.