Instructables
This article is about the brick oven I made in my back yard. There are lots of similar articles on the interwebs, but I decided to post mine anyway.  There are a lot of variations, so my oven may be informative to others who are designing their own oven.

Just to be clear, this is a black oven.  The fire is burned on the hearth.  Before cooking, you have to move the coals to the back of the oven (for pizza) or sweep them completely out.

Mr. Wikipedia says:

          http://en.wikipedia.org/wiki/Masonry_oven

and

          http://en.wikipedia.org/wiki/Wood-fired_oven


 
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Step 1: Foundation

There are basically 2 methods for making a foundation: slab or footings.  I used a slab because I felt that the weight and geometry of the oven did not require footings.  A house, which weighs much more and is distributed over a much larger area, requires footings.  Variation in soil type and moisture level in the soil at different locations around a foundation are more likely to occur for buildings that have a large footprint.  This little oven is light and compact in comparison and does not need such an elaborate or expensive foundation.
BigCountry3 months ago

A local here built an oven from adobe. he used willow withes to make a rough basket then cover it in damp newspaper to form the mud over. after the oven was built he fired it with a slow fire and burned all the paper and willow away. That's how I'm building mine.

godbacon3 years ago
the polystyrene scares me. It's toxic if it burns or melts... is it necessary? Heat rises and all, but It still throws up a flag in my mind.
neffk (author)  godbacon3 years ago
Good question. I had to make a number of design choices based on the empirical (and probably unreliable) experience of others. There was a great deal of emphasis on the under-hearth insulation, but I'm not sure it matters much. The same camp claimed that 8" of insulation above the dome is needed, but I have 2-3" and it never gets ofer 160 oF near the outer edge of the unsulation. Point is, you could probably do without it. The vermiculite concrete is probably adequate.

Foam insulation is basically a solid form of petroleum, so you're right to be worried about it. However, I don't think there's much danger in my design.
neffk (author)  neffk2 years ago
So that temp measurement was wrong. I now have 4-6" vermiculite insulation over the dome, which is enough. More would be better.
fzumrk4 years ago
Some notes on footings for people who may be planning their own projects:

* If you are building in an area with cold winters, you may want to dig the foundation down to the 'frost depth' for your area. You can get this information from your local building or planning department. This will prevent the footing from being moved up and down by the soil freezing and thawing which could break up your masonry structure, or cause it to lean. A deep bed of compacted gravel would make an acceptable substitute for full concrete foundation, as most of the water will drain out of it.

*I would locate something like this away from large trees, especially if using a very shallow foundation. The tree roots will eventually move the foundation.


godbacon fzumrk3 years ago
are you a code enforcer or an insurance agent? LOL :)

I believe the author is in Minnesota, if it's like Maine, no one is really going to dig down 6 feet to get below the frost line. That would be a huge hole.
neffk (author)  godbacon3 years ago
The purpose of footings is to support heavy objects and to prevent un-even shifting of a foundation. My oven is quite light compared to a house and it is on a slab that isn't even 6' square. If the ground heaves, the entire structure should move together, not crack.
hjliv4 years ago
Excellent Instructable!

If you ever make another one:

One traditional (oldey tymey) way of forming the dome (beehive) is with moist sand. Make a dome of sand and lay your bricks over it. Once the mortar has set, scoop the sand out.
neffk (author)  hjliv4 years ago
Good point. It is a lot of sand, though.

I think my form was really poor and unpleasant to work with. There are still bits of pink foam in my yard from the struggle to get the form out!

Making forms, I think, is boring but very important. If I were to make another oven, I would make the forms FIRST.
drewgrey neffk3 years ago
I used the sand method and after dumping the first bag of sand in I was like... HOLY COW thats going to take alot of sand. I called some friends and had a whole bunch of empty quart pop bottles(lids on) and olive oil cans (same) deliver to take up space. I also used a beach ball.It was the best because I put the valve toward the opening so deflation created an opening .
The beachball is pure genius!
vincent75203 years ago
great job : that's how all ovens should be wood cooking gives such a nicer tast e!!…
neffk (author)  vincent75203 years ago
It is fun. But having used it for a while, I have to say I appreciate my electric oven, too. It's fun to have a baking day, starting the fire 4+ hours before baking, but it's really too much for a single family. I'll have to get my neighbors involved. And it's cold up here in MN, so it becomes a chore to bake in the winter. Still, I'm glad I built it.
Good idea to have your neighbors involved. It will make your oven a friend maker !…

Otherwise let it be a summer oven.

I was wondering : the small roof over the oven seems a little bit too close to the top of the oven (despite insulation). What do you think ?…
neffk (author)  vincent75203 years ago
It would be nice to have a little more clearance. I measured the temp just under the surface of the vermiculite and it gets up to 140-160 oF. I think it's safe enough, but if I was building it again, I'd leave another 12" or so.
k-twizel4 years ago
how long does this take to heat for pizza or bread. It seems to be more inductive heat rather than direct (i.e. heat the oven from below without burning wood inside vs. burning wood in the oven) Or is the bottom just for wood storage? Would love to see the oven 'in action'. Good tutorial too.
neffk (author)  k-twizel4 years ago
It takes about 2.5 hours to get it up to temperature.

It's a black oven, which means the fire burns on the hearth where you eventually cook food. Obviously, some effort is needed to minimize the amount of ash that ends in the food. I use a wire-bristle brush to which I've attached a long handle.

After pizzas are made, there still a lot of heat to be used. After people left the first pizza party, I cooked a pumpkin and roasted a chicken. The oven was still 300 oF the next morning. I fired it that night for more pizza, and am cooking chickpeas, 2 more large pumpkins, and my wife's chili-lasagna invention. I'll dry some pumpkin seeds, too. There'll still be lots of heat left over. I'll have to coordinate with my neighbors next time...

Cyrus neffk3 years ago
Cooking pumpkins?
neffk (author)  Cyrus3 years ago
Right. We had a lot this year and I don't have a proper root cellar for storing them. I seeded and sliced the pumpkin and piled the slices in a casserole. I cooked them for a long time---over an hour. Then I scooped the flesh out and froze it in quart bags. The next week, I cooked 7 more pumpkins. There was still room in the oven for more!
cory.smith4 years ago
I saw your chimney and I laughed. Hard. Sorry, but it was just too funny. Good instructable, though.

I am impressed that it stays that hot for that long. Impressive.

And your brick front looks good, as well as your arch. That's not easy to do.
neffk (author)  cory.smith4 years ago
Yeah. It's embarassing, really. But it's functional, so I can't bring myself to tear it down. Maybe the tree will fall on in and I'll have a good reason to fix it.

I was worried about heat storage because I laid the firebrick the thin way (2") instead of the thick way (4.5") would be a problem. But I couldn't afford 300 firebricks, so I'm glad it works.

People have been making ovens out of stone, brick, and clay/mud for thousands of years. The obsession with firebrick is a recent development. It's reliable, but probably overkill for most residential ovens. If I did this again, I'd do firebricks for the hearth and first course, then finish it off with regular bricks.
drewgrey neffk3 years ago
I ran my firebricks the thin way also but used a special cladding mix. Have you found a good source for cheese. Most mozzarelles are made healthier today and lack the salt and fat that were the secret to its cheesy greatness.
neffk (author)  drewgrey3 years ago
No, I haven't looked into that---yet. I understand the quest for the perfect peperoni is also alluring.

No, mainly I've been working on the party pipeline---pizza makers keeping up with the oven and vice versa. It's tricky when only a few of your guests have been initiated. 30-40 pizzas is a typical party, so small differences do matter.
drewgrey neffk3 years ago
It sure is fun to watch the little kids rolling out doe and building their pizza.We have been cheating in the doe dept. as we get ours from trader joe's.
stormy03144 years ago
I am not sure about the chemistry, but heating galvanized metal releases a form of zinc which is poisonous. Better to go with wood or stainless or aluminum even. Maybe ask a chemistry teacher. Nice build.
neffk (author)  stormy03143 years ago

I just ordered a perforated banjo peel with sliding grips:

http://www.fgpizza.com/store/media/2030-Banjo-Peel-pizza-turner.jpg
Stainless. Aluminum will melt or burn and thats no fun.
My welding shop teacher welded Galvanized metals for 30 years w/o a respirator and the fumes ATE AWAY HIS STOMACH SO BAD THAT HE HAD TO HAVE A TRANSPLANT FROM A EITHER A GOAT OR A PIG ONE OR THE OTHER HE TOLD ME THAT SO LONG AGO THAT I DON'T REMEMBER WHICH AND HE WASN'T A LIAR SO FOR THE LOVE OF YOUR BODY DON'T USE GALVANIZED METAL.
neffk (author)  wrksnfx3 years ago
I was reading on the interwebs and there are lots of comments about people feeling ill after welding galvanized metal. Welding produces all kinds of terrible gases that you shouldn't breath, so I chalk this up to poor ventilation.
neffk (author)  stormy03144 years ago
I understand that welding temperatures are a problem, for sure. I don't think the peel gets THAT hot.

Anyway, an aluminum peel is better and cheaply available. I didn't buy one because it couldn't be shipped and received in 15 minutes.
soundmotor4 years ago
I've thought of using rubble/concrete fill on some of my own projects; you dissuaded me from that. Stucco is nice but it cracks and flakes off quickly if improperly applied. I am dealing with that issue right now with a contractor, sigh....

Rather than stucco, you might consider mortaring up the rubble face until reasonably smooth then skim-coating with concrete to smooth it even more. Finally, finish the sides in whitewash and have a country look to it. That would highlight the front brick nicely (which looks great BTW).
neffk (author)  soundmotor3 years ago
I'm going to have to put up screen first because some of the voids are several inches deep. I checked up on mortar vs. stucco and don't see a huge difference. Different ratio of portland, lime, sand, as far as I can tell.

mrichmond4 years ago
Nice project, been wanting one of these myself for a few years now. You might rethink using the galvanized metal for the peel, or at least make sure you don't get too much tomato sauce on it.
http://www.galvanizeit.org/images/uploads/drGalv/hdgsteel_food.pdf
Otherwise, great work!