Life Changes/Brick Oven

Hello hello, everybody. My senior thesis has been submitted, assessed, and returned: I'm graduating! Heyo! After a summer in Houston, I'll be moving to the Mississippi Delta in the fall to teach high school Spanish. Adventure time.

In the lull between senior exercise season and finals, I decided to look for a project. Since the school-owned apartments do not have ovens, a makeshift brick oven seemed like the perfect choice. Here's the current design, which one might call version 2.0 of the oven.

The walls are two bricks thick, the floor is one brick thick on top of cinder blocks, and the roof is a stout granite boulder. This is a huge improvement over the previous design, which was only one brick thick all around except for the roof. However, it still loses a huge amount of heat: as one can see, the boulder is not perfectly flush with the walls and support bricks. I guess I can't complain, since all of the materials were free.

Perhaps I will try plugging the gaps with mud and then wrapping the thing in tinfoil, as described by Hans Fugal on his wonderfully informative page, Brick Ovens for the Cheapskate.