Oregon 46" Neapolitan Wood Fired Oven Build

[CharlesPizzaiolo]

Hello!

This is my first post on the Forno Bravo Forum. I'd like to share my oven build. I started in December 2018 (I know, not a great idea but I was too impatient to wait for warmer weather). There is a link in this post to a time lapse of pouring the foundation. I have almost no experience with concrete and little experience with construction in general so go easy on me

[cbailey]

Hi Charles,

I stumbled across your post. Starting a project like this is always a challenge, but January in Oregon adds another dimension. But I understand your impatience.

I'm not an expert on this Forum, but you'll see more traffic on the Pompeii Oven Forum. Check out the link:

https://community.fornobravo.com/for...n-construction

I'm looking forward to following your build.

Cory

[CharlesPizzaiolo]

Hi Cory,

Thanks for the advice and for checking out my thread!

After we poured the concrete we made a double-layered tent out of a canopy and tarps and put an electric space heated in there. That kept the slab plenty warm for a few days. You can see I put plastic over the slab to keep in moisture, but I think I should have waited until the surface set a bit before putting the plastic down. The surface finish is rough and I think its because we immediately put the plastic down.

Here's my next video. Its 3 minutes and not alot happens but I'm too lazy to edit right now Eventually I will edit these all together. Its just me uncovering the foundation and dry stacking the cinder blocks. Since the foundation was a bit rough in some parts, I used a little mortar to make a couple of the blocks sit a little better.

[CharlesPizzaiolo]

I've gotten behind on posting, I'll try to catch up. Here is us pouring concrete in every other hole to lock the cinderblocks in place, as the FB plans suggest. I used two pieces of angle iron to hold the cinder blocks above the opening. I dropped rebar down the holes and I cut them long so that I could use them to hold up rebar for the hearth slab later.

[CharlesPizzaiolo]

Here I'm building the forms to support the center portion of the hearth slab. I know, I've overbuilt them, but I'm new to this kind of construction and I was paranoid better safe than sorry, right?

[CharlesPizzaiolo]

Next I started building forms around the perimeter of the stand. I need these because My slab is going to overhang the stand by about 6 inches. I chose to have it overhang because I thought it would look good. Not sure if it was really worth the extra effort required to build these forms. At about 6 minutes in, you can see me installing some short vertical pieces of rebar in the center. These will hold up more forms, it will make sense when you see us pour the hearth slab.

[CharlesPizzaiolo]

Finally, I installed the rebar for the hearth slab. You can see my slab is going to be quite thick. I did that because I wanted to have the top of the slab even with the oven floor. So 4" of concrete in the center, plus 2" of insulation, plus 2.5" of brick, plus an extra 0.5" of sand for getting the brick level: that's a 9" slab. Again, if this isn't clear now, I think it will be once you see the finished hearth slab.


You can me temporarily place the center form (the circular thing with all the styrofoam). That will create a void in the center of the hearth slab. That void is where the floor insulation and bricks will go.

You can also see me installing a white paper tube near the back of the oven. That will serve as a smoke passage. I'm going to build a firebox behind the oven and smoke and heat will travel through that hole (and holes in the oven floor and walls) and into the oven chamber. So my oven will (hopefully) double as a smoker. I got this idea from another guys build video.

[david s]

Finally, I installed the rebar for the hearth slab. You can see my slab is going to be quite thick. I did that because I wanted to have the top of the slab even with the oven floor. So 4" of concrete in the center, plus 2" of insulation, plus 2.5" of brick, plus an extra 0.5" of sand for getting the brick level: that's a 9" slab. Again, if this isn't clear now, I think it will be once you see the finished hearth slab.


You can me temporarily place the center form (the circular thing with all the styrofoam). That will create a void in the center of the hearth slab. That void is where the floor insulation and bricks will go.

You can also see me installing a white paper tube near the back of the oven. That will serve as a smoke passage. I'm going to build a firebox behind the oven and smoke and heat will travel through that hole (and holes in the oven floor and walls) and into the oven chamber. So my oven will (hopefully) double as a smoker. I got this idea from another guys build video.

If you have a bathtub in the centre of the supporting slab a few drain holes near the centre to allow for drainage should water accumulate there is imperative IMO. These can be cast into the slab on pouring rather than having to drill later. My ovens are way smaller than yours but use a similar idea.

[CharlesPizzaiolo]

That sounds like good advice, david s. Do you get much water coming out of those drain holes?

I already poured my slab so I'll just need to get a concrete bit and drill through. There were some low spots in the center of my slab so that will be a good place for a drain hole.

[CharlesPizzaiolo]

After weeks of delays, we finally poured the slab. The only problem we ran into was that my 2x2s bracing the walls of the form were not enough. The sides were the worst and we were able to brace those. The front and back weren't bad.

[SableSprings]

Looking good Charles! In addition to the weep hole suggestion by David S, you might also consider laying some sheets (upside down) of small mosaic tiles down to create mini-channels leading to the weep holes. This keeps any insulation board or water absorbent materials from being in contact with the concrete top slab (and any water/moisture that may temporarily gather/wick up from there). I've added a link below to a build in Idaho with good illustrations/documentation. Posts 11-21 in his build deal with things you might find relevant/interesting.

https://community.fornobravo.com/for...andpoint-idaho

[CharlesPizzaiolo]

Thanks for the link, SableSprings ! Right now I've got a layer of sand on the concrete to get a level surface. The plan was to lay the insulation board right on the sand. Do you think the sand would allow drainage well enough that I wouldn't need to do tiles?

If I do tiles, I'm thinking I'll take out the sand I have now, put down tiles, and then add sand back on top of the tiles to get it level. There are some high areas in the concrete where I have little to no sand, so I wont be able to put tile there. I cant raise the height of my oven floor because my design is to have the floor flush with the top of my slab.

[david s]

Probably better to add a skim layer of sand and cement while the concrete is green to get it level.

[CharlesPizzaiolo]

While I'm working on the slab and floor, I'm also pouring pieces of my dome in my garage. I decided to do a cast dome instead of firebrick because it was cheaper and I also thought it sounded like less work, since I was going to trim all 200 or so bricks to taper them and then laying them (and I've never laid bricks before).

Considering how much time I'm going to spend pouring segments and rigging up systems to move those segments around, I'm not so sure that its actually less work. But still cheaper

Anyway here are some photos of my form and of one of my test pieces I made with regular concrete. And also my temporary lifting setup. I lift the segments (which weigh around 120 lb) straight up, move the form out of the way, and then set them down. I just picked up a winch which should make that part much easier!

My ultimate plan is to build a wooden overhead crane with a horizonal beam and a cart with casters that can roll along that beam. And I'll mount the winch to the cart. If that works, I can stage my segments next to my oven and then lift them and set them into place with my crane. If it works, it will be pretty slick! And as you can see, I install a rebar lifting point in each segment, so when I lift the segment it is oriented correctly so I can set it right into place on the oven floor. I know its a crazy idea but it should help alot with assembling the dome.

I know I could have made each segment much smaller and easier to lift by hand but I thought bigger pieces would be better because I'd have to pour less of them. I didnt think about how I would lift them... but now with the lifting points I think it will be even easier to mortar them and set them in place. We will see...

[SableSprings]

Back to the base...sand will wick water up, so you want to do as David suggested and use a skim coat to rough level. Lay down the tile sheets to provide a moisture barrier and channels to your weep holes. Put your CaSi board on the tiles, then use a thin layer of sand and fireclay mix on top of the board. (If your board is level, you may not need to put the sand/clay layer on.) If you need the leveling sand/clay, just add enough to be able to use a notched trowel on the lightly moistened mix. If you're pretty close to level on the board, that thin layer will allow you to set the firebricks level pretty easily.

Be aware that when you place your cast pieces around the edges of the cooking floor, you may cause the cooking floor to lift up a bit. Just something else to watch...