I could use some more heat retention in the back of the oven. Should I, could I put another reinforcing layer on the backside? i.e. either another set of bricks (which I have room for) or another insulation layer or a vermiculate/refractory layer? thank you Bill
Hi Bill, and welcome to the BrickWood forum.
It might be helpful to tell us a little more about why you need more heat retention in the back. Are you feeling “hot spots” on the shell? Or are you concerned that the insulating blanket wasn’t thick enough when you built your oven?
I’m not trying to second-guess your judgment at all, but I do know from experience that the rear of the oven tends to be where the burning logs end up, and so under pizza-baking conditions it doesn’t need as much insulation.
That’s not always true, though, especially if you are baking in a pre-heated flame free environment, where any heat leakage will make a difference.
So, let’s talk a little more, because even though the answer is a qualified “yes,” it would be great to know more about how you’re using your oven.
Thank you for the initial response. I have found that the right side of the oven does not retain as much heat (slower to get the temp in the seven hundred degree range+) so that the pizzas cook quickly, thus, I have the left side pizza cooking faster than the right side. Not a huge deal but I thought reinforcing the back side of the oven would help? I have room for another row of brick / mortar/ insulation etc.
Also, can I fill in cracks/gaps in the ceiling fire brick?? Might that help as i have some of these…
Thank you very much. Bill
Great observations and helpful, thank you!
My opinion is that adding more insulation to the back wall of the oven won’t help with that issue, unless you are feeling heat (not just warm, hot) on the shell at the back, on the right side. Even if you have the room, it won’t do much for you.
Following is some general information and an order in which to proceed.
Your oven is designed to manage heat in a couple of ways:
- by absorbing heat into the firebrick and then radiating it back into the oven
- by keeping heat from getting past the outer surface of the firebrick
The arch or barrel shape convects heat and keeps it in the atmosphere, and the burning wood radiates infrared heat.
The barrel absorbs and radiates the bulk of that heat down, toward the floor, rather than through the front and back walls.
Unless you have spots in the rear wall that have no insulation whatsoever, you’re not going to gain a lot by adding more there.
Something you could try is to build your fire by cheating it toward the left side of your oven while it’s heating up. See if that heats your right side up more.
Many of us set up our fires by starting at the front, then pushing the entire fuel load by stages gradually toward the back (say, every 20 minutes or so). When it’s time to bake pizza, you should have a roaring flame along the back wall, with the flames licking up and maybe a third of the way into the top of the barrel. That should give you the even coverage you’re seeking.
If you experiment with things like this and are still convinced it’s a problem with the rear wall construction, then you can think about adding more brick back there. If you do, keep in mind that for it to be effective, you will in effect have to rebuild the back wall (carefully remove stucco, cut away chicken wire, and fold back any insulation) because your new materials will need to be in contact with the original construction to perform the insulating function you want.
You already know how to lay the brick for the curved back wall, insulate, and stucco (which will need to be sealed to the existing stucco along the barrel). And the bright side is that you’ll be able to see if something “went missing” (it happens!) when you were building that end the first time.
Hope this all helps, Bill. Let us know your progress here, and we love photos on this forum!
Very good input. I think I can keep as is and build the fire in the center. I need to be patient with feeding the fire and get the temp up. What temp do you shoot for with your laser gun before starting to cook?
Thanks.
Bill
Yes. You should expect firing up to take an hour at minimum. You want the heat to soak into both the arch and the floor.
As for the laser gun: I shoot for a minimum of 700°F on the oven floor. It is the only measurement that matters. If you’ve got 700° on the floor, and good flames licking out into the arch, you’ve got amazing pizza on the way. If you don’t, you’ve got doughy pies and frustration.
You’ll find that when you’re near or at that temperature on the floor, you’ll also need protection on your hands and maybe your face in order to stand close to the oven mouth. I only mention it as a secondary rule of thumb. 