Simon's 36" LA brick oven

[Neil2]

Re: Simon's 36" LA brick oven

Simon

I would lay out the rebar in a grid pattern. Calculate your rebar volume to total about 1.0 % percent of your slab volume and space it both ways evenly. Put a double bar in wher it spans the entryway.

The "radial" system that you are proposing is somewhat problematic in that you will end up with a mass of rebar crossing in one location and will have difficulty in getting adequate concrete cover on the rebar. Conversely, if some of the rebar is ended before the "centre" then you will have "dead ends" which will contribute much less strength to the reinforced slab.

Bending the rebar down into the concrete blocks, as you have done, is the best practice. Most people put verticals in the wall and bend them down 18 inches or so horizontally to provide an overlap tie to the grid rebar. This is done only to make the rebar placement more convenient. Having the rebar continuous in one piece is actually slightly better but provided you have adequate overlap (12 inches) then either technique if fine.

[HummerGB]

Re: Simon's 36" LA brick oven

Simon - I'm no expert, so I hope someone will chime in, but I"m concerned about the amount of rebar you are using. It's more or less a free standing slab, so I would think alot more rebar would be appropriate.
Leigh

Re: Simon. Take some cutoff sticks of rebar and send them down the holes. Slush in the holes. Every other is good. then lay out the tray for your slab. Then lay out your rebar. make 6x6 squares. Where your cantiliver is lay rebar 2" parallel to your edge and then run bars 90 degrees to the edge. bring them up 1-2" from the edge and back into the slab with wire. Suspend the bars half deep . I have a 55"x 55" hearth and burnt up 120' with a 12" overhang in the front. I enclosed a pic to reference from . If your worried about those pillers moving, once thier slushed in I doubt you need to tie them together. Remember your going to have about 1800lbs min on top the hearth. My small hearth is 1000lb by it self. I hope this helps.

[rodeair]

Re: Simon's 36" LA brick oven

Simon - This is a shot of what I did for mine and was a little worried it wasn't quite enough.
Leigh

[GianniFocaccia]

Re: Simon's 36" LA brick oven

Simon,

I'm no expert either, but if it were me, I'd remove the center column since it leaves quite a bit of dead storage space. You may want to consider reconfiguring the blocks from that column into a wall that extends from the center of the slab diagonally straight back into the corner. This leaves you with two separate (accessible) usable storage areas under your slab. You will still need to place your rebar in a grid fashion.

John

[brickie in oz]

Re: Simon's 36" LA brick oven

The centre column will become redundant when the slab is cured.

[Grtiz]

Re: Simon's 36" LA brick oven

Can you describe your foundation layout. I'm curious about the extra you have on the side.

[Neil2]

Re: Simon's 36" LA brick oven

If you are using 1/2 inch rebar, this has an end area of 0.2 sq inches.

If your slab is 5 inches thick, to achieve a rebar percentage of 1% you will need to space your rebar at 8 inches on center both ways. Your long span looks to be under 7 feet, skip the center column.

Every other rebar can bend down into the wall (or tied to a rebar bent out of the wall). The other rebar could also be bent into the wall or be "hooked" at the end (or bent at the end to lie flat). All rebar ends should be embedded in one of these two ways. Dead ended rebar is useless for the first foot or more of its length.

Rebar is cheap. You already have a bending tool.

If you haven't already bought the rebar, you may want to consider 3/8 inch rebar instead of 1/2 inch. It is much easier to bend and cut and will give you a slightly better cover depth in the slab. (If using 3/8 inch rebar, reduce your grid spacing to 6 inches.)

[calipizzanapoletana]

Re: Simon's 36" LA brick oven

Thanks very much to all for the responses and direction - I'll bend the rebar to form a grid, and will remove the center column (yay! more blocks for the rotisserie oven).

Neil - yhea, already bought the rebar, but glad i did. As hard as the damn stuff is to bend, I suspect it will have greater structural integrity for when the next earthquake strikes. I'll bend and sink every span of my grid into each side of the form.

Gritz- The extra block form on the right side of the oven foundation is going to be a rotisserie oven/grill. I was thinking about building a small barrel vault chamber, that could also work as a rotisserie, but am concerned that I don't have enough space in front for a vent. So I'm debating about doing an open top rotisserie, or a true rotisserie oven. I really want to make an enclosed rotisserie out of brick, though, bad.

[Mike D]

Re: Simon's 36" LA brick oven

-Hey Simon here is a picture of my rebar just for fun. I come from a long line of over builders and could not restrain myself with some sort of center support.

-If I was to do it over again, I think I would of done it with shallow wood area in front and a side opening in the back to separate it into two compartments (like Dino and others did). That way you wouldn't have to crawl way into the oven to get wood, and you could use the back side area to store charcoal or something.

Mike

[calipizzanapoletana]

Re: Simon's 36" LA brick oven

Mike - Thanks for the photos, I agree that it is a better design to have the additional storage compartment, as opposed to the one large space underneath the hearth... but seeing as I've rebuilt the whole thing three times already, and spent the amount I had budgeted for block, I'm sticking with the one large wood storage underneath. The rotisserie oven will have a small space for kindling storage underneath the charcoal pit. I'm also thinking now of a system of four to six, depending on size, wood storage squares, on casters, below the pizza oven to rotate the wood around (like one of those puzzles where you move and shuffle tiny squares in two dimensions -having one open space with which to move a square from one of the four cardinal directions into that space, which in turn opens up another space, and so on...)
Still with me? That way I could easily bring a stack of wood from the back of the oven to the front and vice-a-versa.


I'm going to upload in a minute some new photos of a angle iron span I put diagonally across the front of the oven, it was tricky to get the angle for both pieces of iron cut into the blocks with my brick saw - I was just holding the block and using the saw as a stationary grinder, not using the guide tray. DO NOT DO THIS - I managed to accomplish the task without breaking the saw or loosing a finger, but I won't ever quite be so stupid with the tool again. I should purchase a grinder...

[Mike D]

Re: Simon's 36" LA brick oven

I didn't use the angle iron, I poured into a form over the gap. I was having a problem finding the angle iron and liked the idea of changing the plan.
- But keep it up, and don't hurt yourself. That would be a bad story anyway (Yea I cut my arm building a Pizza oven). You would have to make up another story to tell people.

Mike

[calipizzanapoletana]

Re: Simon's 36" LA brick oven

Proceeding ahead - my friend Eric came by this evening and we built the interior 2x4 wood form and plywood tray for the hearth. Tomorrow I'll tackle the side forms and those for the rotisserie oven's hearth.

Pictures tomorrow evening of the progress (hopefully )

Question- For the insulation underneath the oven floor, someone have a good vermicrete mix recipe?

[calipizzanapoletana]

Re: Simon's 36" LA brick oven

So, its been about six months since my last post, and boy has there been progress. In addition to completing the dome three days ago, I've also just ordered a 68" section of double wall flue pipe, a spark arrestor, and an anchor plate, plus a second box of 50' insulating blanket.

The dome ended in just about the ugliest fashion I could've imagined, with the cap being three full bricks cut with angles on both sides. You can see in the photos in the following posts how screwed up the top of the dome is, however it is solid- with the last four shims being pounded in with a rubber mallet until it was tight as rock. Hoping that this holds- should I point up the spaces/gaps in the interior?

Ended up putting a little overkill on insulation- the base has 4" of foamglass on the concrete, then on top of the foamglass is 2" of calcium silicate board. The brick dome and cooking floor is then on top of the cal-sil board.

Kind of amazed that it looks as good as it does.

[calipizzanapoletana]

Re: Simon's 36" LA brick oven

below are photos of the interior sides of the dome, arch, and a photo of the amount of sand that filled the dome.

[calipizzanapoletana]

Re: Simon's 36" LA brick oven

photos of the top of the dome - please be kind - she may be ugly, but she is solid.