Finally Started in Southbury Ct.

[Aegis]

Well we have finally started the brick oven/ patio build. I am currently planning a pompeii style oven following the forno bravo plans. Size is in the 42" area (38 - 42 ) depending on feedbacjk from site members. I want to use it for baking pizza's (I am hungry already) and bread with the emphasis split between the two. I wanted some feed back from people who have built and are using their ovens how long they retain heat and how much heat retaining mass they used in their ovens.
Here is a link to my progress as of today!
John's Brick Oven Folly - John Lazy's blog - Blog
ok so the name has no originality, I am hoping to save originality for the actual build.
Let me know how and what you used for your hearth layer (two courses of hearth bricks, one? any refactory layers under and over, how thick? insulation where and how much? ) how long does it take for a complete firing/heat soak and how long do you have temps above 450 degrees F ?
Thanks in Advance
John

[Jed]

Re: Finally Started in Southbury Ct.

Hey John,


Glad to hear you are starting an oven build.

I built an oven to the general specifications that Forno Bravo gives in the free Pompeii plan set.

So, I used perlite / cement mix as the insulator under one layer of fire brick (2 1/2 inches thick). I used a fire brick cut in half as the building material for the dome (so the dome walls are 4 1/2 inches thick) and then insulated the dome.

It takes me around two hours to heat my oven to a 'heat saturated' point. If I am attentive when I pull the fire, the oven will be a solid 450 degree's F the following morning, and in the high 200 degree F range by the end of the day following a fire. I can still slow cook something through the night the following day.

If I build another oven, I would use factory insulation below the cooking floor and around the dome to improve heat retention.

Good luck with your build.

JED

[Aegis]

Re: Finally Started in Southbury Ct.

Thanks Jed, I really appreciate the feedback! I am looking at using 4" of foamglass under the hearth for insulation, but also either adding 2" cement under the hearth bricks for more heated mass or laying the firebricks on their side instead of flat. I do see the possiblitiy of many more edges to "catch" a peel on while using it with the "on edge" design That is why I am not committed to either idea as of yet. I love the fact it only takes two hours to totally heat soak your oven and I guess if I want to bake bread the next day another firing of maybe an hour would bring it back up to 500 degrees and keep it there without the added mass. It appears the insulation as it relates to brick ovens is like fun, you cannot have too much of it! So I will adhere to the voices on this forum stating you cannot have too much insulation.
Do you have any pics of your oven? And again thanks for the info, I guess not many people who have a completed oven are on the site much, they are making pizzas!

[Aegis]

Re: Finally Started in Southbury Ct.

Well I am ready for a cement truck to pour the foundation. I dug 8 holes 12"x42" deep for a below frost foundation pillar. Put down 6mil plastic on top of 6" deep 3/4" gravel. I also have put in a 1 1/2 inch electrical conduit for lighting and powering the thermocouple system. Here are a couple of pics of the forms. The left side will be a counter for working and such. On the right another small 2.5' counter.
I'm trying to figure out the insulation under the hearth. I am leaning towards 4" of foamglas, but I am not sure how to secure it and if I need to cover it with something????

[Aegis]

Re: Finally Started in Southbury Ct.

Slab is poured and patio based is almost finished. I have the electrical run to a "street" lamp and also lighting and power for thermocouple meter. Here is a pic of the slab.

[KraemerBAC]

Re: Finally Started in Southbury Ct.

I look forward to seeing the progress...

Peter

[Aegis]

Re: Finally Started in Southbury Ct.

Okay, I am starting to dry stack my stand and without mortar, this 16" blocks aren't 16 inches. I plan on facing the block with either bricks or a small paver. My question is: Will I have dimension issues with the stand being an un-standard size? Will I have many bricks to cut and fit on the exterior? If so would I be better off to use mortar joints to achieve a standard wall? I have OBVIOUSLY do NOT have any masonry knowledge.
Thanks in Advance

Here is the patio section ready for sand and pavers, next is the first stacking of block for stand! YeeHaw!

[Aegis]

Re: Finally Started in Southbury Ct.

Ok I am playing legos with the cement block, trying different openings to the rear section. I love Dino's side entrance and wanted to simulate that on my build.
Now I have dry stacked four courses high without motar on the bottom course (trying different setups) and I find the blocks are almost perfectly level. My question is do I have to mortar the first course for lateral structural support or is it just for leveling? If leveling is the ONLY concern then I may be good to go. I'll post some pics after the dry stack is done.
Thanks for the help!
John

[Aegis]

Re: Finally Started in Southbury Ct.

I have another question to ask, where to position thermocouples? The Hearth is an obvious place, but should there be more than one in the hearth? And where would those be placed? Front, middle and back? Maybe a couple in the dome and some in the insulating areas?
Also any tip on the placement of electrical conduit thru the hearth slab? And an ash drop needs to be under the flue or outside of the flue area?
Thanks in advance
John

[Aegis]

Re: Finally Started in Southbury Ct.

Lots of questions, I have, answers I have not....

[Millstone Man]

Re: Finally Started in Southbury Ct.

John - You do not need to mortar your blocks. Just but rebar in the cores when you fill them with concrete. I have not finished my oven yet but opted to omit the ash drop after reading through this website. Most seem to say it's not worth the effort. You might do a search on ash drops and read what others have said. The same for the thermocouples. The FB plans are really good. - Scott

[dmun]

Re: Finally Started in Southbury Ct.

16" blocks aren't 16 inches.

None of them are. They are half an inch off in each dimension to make room for mortar joints and still have their nominal dimensions. If you've never laid block before, you don't want to start now. For something that's so commonly done, it's amazingly difficult to get the mortar to perch on the edge of those hollow blocks. The plans call for dry stacking and filling for a reason.

do I have to mortar the first course for lateral structural support or is it just for leveling? If leveling is the ONLY concern then I may be good to go. I'll post some pics after the dry stack is done.

nope, unless you are in an earthquake zone you don't need to mortar the bottom row of blocks except to level it.

where to position thermocouples?

About the only use for thermocouples is to measure the heat saturation of the dome, to get repeatable results in bread baking. If pizza is your main goal, then you almost certainly don't need them. If you are a maniac for bread baking, I'd put one (actually two, in case one fails) at the top of the dome, about half way in. That way you'll know if your dome has the same amount of stored heat, hot weather or cold, raging fire or slower one. I can't imagine any use for a thermocouple in the floor. Heat always rises.

And an ash drop needs to be under the flue or outside of the flue area?

Again, an ash drop is a bread thing. If you are daily shoveling out live fires to prepare for bread baking, you may want to consider expending the effort and space for an ash drop. If pizza is your primary goal, you'll only have a little bit of ash to shovel out the next day, or before your next bake.

[Aegis]

Re: Finally Started in Southbury Ct.

Thanks Scott and dmun, I have dry stacked the stand and it is extremely level. This was mostly due to my friend who floated the slab nicely. I did quickly find out about the 15 1/2 inch blocks when I took a final measurement of the stand. It helped me with the vertical dimension, since I will be using 4" foamglas under the hearth and I am considering laying firebrick spilts and then regular size firebricks on top of those for the hearth. I am not sure if the extra mass will be needed for bread or not. I will be looking to do both pizza and bread in the oven. It seems to me the walls are 4" thick and to have an even heat soak the hearth would need to be four inches also. I do realize heat travels up and the hearth would normally be cooler, which would compound the bread baking problem. Bread likes a hot bottom for spring/rise, although a brick oven might do that oven spring from all directions, not just bottoms up so to speak. Hmmmm did someone say bottoms up, I'll drink to that!
Thanks for the input on the ash drop, I will be doing bread so I guess I will need to figure out a good form to use for the pour. I will no doubt change my mind a couple of times before I have to commit. It not only will help/hinder the pizza/baking process. But it is also a front facade change, for either using the bottom for wood storage, or ash containment/removal.
And two thermocouples it will be in the dome.
Again MANY thanks for your input!
John

[fxpose]

Re: Finally Started in Southbury Ct.

I am considering laying firebrick spilts and then regular size firebricks on top of those for the hearth. I am not sure if the extra mass will be needed for bread or not. I will be looking to do both pizza and bread in the oven. It seems to me the walls are 4" thick and to have an even heat soak the hearth would need to be four inches also.

How about laying the firebrick on its side like they do in bread ovens......that'll give you the thickness/thermal mass you're looking for.

[Aegis]

Re: Finally Started in Southbury Ct.

Without the experience, I thought the trade off of splits under would be better than the extra lines that the side laying would give. Any comments would be greatly appreciated. I am also not sure if the extra mass in the floor is needed or worth it!
Thanks
John