Heat Pizza dome via ducted feed from fireplace?

[Westerj]

Has anyone heated a pizza dome from an "external" fireplace?

I bought a home with a half finished Pizza dome atop a 6'x6' concrete pad about 54" off the ground. After cleaning it out, I fired it a few times. The lack of a chimney made it hard to keep it lit.

The fireplace on an adjacent face of the cube/pad burns well, as it was a bit more completed, with a chimney.

Was wondering if anyone had used the firebox from a standard fireplace to duct heat into a pizza dome? Sure would heat up faster!

THanks!

[shuboyje]

Re: Heat Pizza dome via ducted feed from fireplace?

You could make a functional oven that way,but it would lack the Proper balance of too and bottom heat and would not reach the ultra high temPs of a standard oven.

Odds are it is wet and once dried out will fire much easier.

[david s]

Re: Heat Pizza dome via ducted feed from fireplace?

It makes a lot of sense to use the fireplace to help heat the oven, although you still need a fire inside the oven too. You are not the first one to think of this idea as the attached pics attest.
The lack of a chimney shouldn't alter the firing of the oven. As Shuboyje says, your oven is probably wet. Keep firing it to dry it out and you should be rewarded with better results.

[Westerj]

Re: Heat Pizza dome via ducted feed from fireplace?

Thanks guys!

Floor of oven would be cold - Gotcha. makes sense.
Normal airflow in/out of the doorway would be interrupted/short circuited - Gotcha.

I could see how a proper Flue above the doorway would create better airflow, and a roof would be wise.

The floor of my oven is plain house brick so its bumpy and full of cracks. Heck, so is the dome (see attached).

Its a hassle to clean up before food goes in.

Perhaps instead i could make a fire tray to stock with burnables, slide it in and start it up.

It came as part of a home i'd purchased, and its half finished, Something tells me I'll be trashing it at some point, but for now, will see what can be done with it!

Am thinking about laying out some turkey wire over the dome and encasing it in some sort of mortar. Would that need to be Heat Stop, or would some portland based mortar work?

I get the feeling this thread should be in some other folder. Where should I restart this thread?

Thanks!

John

[WJW]

Re: Heat Pizza dome via ducted feed from fireplace?

I can't see the interior, but judging from the one pic you posted, I can see no reason whatsoever that your oven would not do a perfectly respectable job at cooking wonderful pizzas, bread, and slow-cook items like ribs, lamb, pork shoulder etc. In fact, it looks like a very nice oven.

Personally, I would add a chimney, but it is not required. It would make it easier and much more comfortable to cook with, but the oven will work without the chimney.

What you absolutely NEED is insulation and some kind of cover to keep it all dry. Whether it be an igloo style, or box-type enclosure...you need something to cover it and keep the water out. The insulation can be ceramic fiber blanket or some type of perlcrete, but again, you NEED something.

There is nothing wrong with that oven of yours except that it is half built. It has cracks like all masonry...water will get in those cracks. Unless you slowly re-cure every time it gets moisture inside, the oven will quickly break down as a result of the water turning to steam, expanding, and making bigger cracks...and the vicious cycle will continue and accelerate until your oven is a pile of rubble. So you must waterproof.

You can add thermal mass (in the form of additional concrete on the outside) if you wish. In doing so you will increase the amount of time required to saturate the oven with heat...and you will increase the length of time the oven will retain enough heat to cook with. But whether you decide to add more thermal mass or not, you still need to insulate it with either ceramic blanket or percrete/vermicucrete....and you need to make it waterproof by enclosing it somehow.

You are more than half way there. Insulate it and then make it waterproof and you are golden.

Bill

P.S.: Your oven should not be a hassel to clean up before food goes in. For cooking pizza you will have an active fire going and it should take no more than two minutes to clean the hearth to a degree appropriate for cooking pizza. Push the coals to one side of the oven using a hoe...using a brass brush, clean the loose ash off the hearth into the ashdrop or large metal dust pan. Then (if you choose) given the hearth a quick brush or two with a wet NATURAL FIBER brush. You are then good to go for pizza.

For cooking bread..the same steps apply but I generally am more careful about removing most all of the ash.

P.P.S. If the floor of your oven is bumpy you may have a tougher time than I do using a hoe to get stuff but a rake would work fine. You would then finish with a brass brush. They are available at the FB store.

[Neil2]

Re: Heat Pizza dome via ducted feed from fireplace?

Is there insulation, either board or vermacrete, under the hearth bricks ? If there is, you have have the beginnings of a good oven and as Bill says you are halfway there.

What is the depth between the top of the concrete structural slab and the top of the hearth bricks ? Are the soldiers (the vertical bricks at the side) sitting directly on the concrete slab or is there some kind of layer under them ?

Also, what is the internal height of the dome and the door height ?

Can you contact the previous owner/builder and ask about the under hearth insulation ?