24" DIY budget Brick oven progress

[pcampbell]

Thanks for all the information.  Is there some sort of calculation for flue diameter based on dimensions of the oven?  This one is 4" and I was insure if it was necessary to be so large.  I know that on a wood burning home oven that puts out 100,000+ BTU, they are usually 6" diameter.  I am wondering if I might be able to extend the archway a little bit, and place the chimney into the archway.  In this case a slightly smaller diameter pipe may be easier to make work. 

[PizzaBrasil]

Patrick:

Looking at your oven seems easy to extend a lintel in front of the entry of the dome.
The lintel, at the end, could be not a structural surface, since the landing area is not (supporting these chimney type).
The chimney diameter on the entry (not in the middle, as is) will be 8 to 10 inches, considering that your oven is about 40 inches (estimated diameter of hearth).

Luis

[pcampbell]

I ended up taking out the vent and filling it in.  Venting out the front is fine.  Ideally yes, I would build the archway longer and stick the vent pipe in the arch.  This would also help with wind.

24" is too small.  Go 30" at least.  30" I think would be fine to have a good amount of very hot coals and easily fit a small 12" pizza in for 90 second pizzas.  You'll never do more than 1 pizza at a time though.  But properly insulated, with a small fire around the sides and cook lots of pizza I bet.

My problem is that I left this out in the rain for 9 months, and it ruined my FB Board insulation (underneath the floor).  So the top, even with no insulation gets hot and stays pretty hot (it's not losing any heat to conduction) where-as the floor will just not stay hotter than 700F.  You can feel the bottom of the 5" concrete slab getting warm below the FB Board.   

This was my first pizza on there, that was like 60 seconds I think it could have gone another 30.

[BurntFingers]

Nice work,  a great start, I would use an 8X8 terra cotta chimney flue pipe.  Probably two lengths to get the smoke and fumes above my breathing area and create decent draft.  The opening of the oven should be around 60% of the height of the dome to keep in the heat and let out the smoke.  I used Alan Scott and Russell Jeavons books to help me design my oven.  It is basically a 3X3ft hearth floor with a tunnel dome above.  I used concrete 3/4" wonder-board as a base for my insulated concrete underlayment for the fire brick hearth. This way I didn't have to remove a plywood form.  It can be over 1000 degrees F in the oven and you can put your hand on the wonder-board and not feel any warmth.  The bricks above are white with that heat.