Completed dry stack brick ovenToday I decided to tear down my dry stack brick oven and replace it with an earth oven. I was particularly interested in how well the aluminum foil held up since it is really a controversial matter. Anyway, the dry stack oven was about a year old, and probably it had been fired for pizza and bread approximately 50 times with dome temperatures getting to over 1,000 degree. The foil had been multi-layered and enclosed the red bricks.
Foiled dry stack ovenOver the foil was insulation, Perlite, with Porland cement added, six to one ratio. Over the perlite was a stucco of quarter inch surface bonding cement. There were some surface cracks in the stucco so probably a very small amount of moisture got in, but I didn't think it was a significant amount. Only later did a chunk of the stucco break off, and this I attribute to the intense fire rolling up over the front of the oven.
As you can see from the photos, there was significant deterioration of the foil. Not only had it become brittle and pock marked, but in some areas it had actually had been reduced to a powder. And this was only after one year. It is sort of hard to imagine that foil could have a significant benefit over the long haul.
No, this was not a scientific study, but I love experimenting with various materials in my quest for the perfect, low-cost bread oven and thought that my experience might be of some use.