42" build in Arizona

[xvandish]

Hello all,

First, a thanks to all for the information and guidance in other threads, it's helped immensely.

Last week, finished the walls and finished filling every other core with rebar/cement. This week I've been buying some materials - chimney pipe and insulation.

I'm planning on a 4" concrete hearth pour with 1/2" rebar through the whole thing and 1/2" weep holes over the oven part of the hearth. I know the 1/2" rebar is pretty big, but It's what I've already bought, so rolling with it. The foundation slab is ~6-7" of concrete with 1/2" rebar through it as well, spaced at a 0.5'-1' grid depending on the spot.

Once the hearth is done, there will be a layer of mosaic tile, over which I'll place 6" of ceramic fiber board. Been raining and I need another pallet of concrete, but hopefully I can get the hearth poured this weekend!

The plan is counter/table on the left, oven on the right, so the foundation was shaped that way to save on some CMU and concrete for the counter since I figured the load would be minimal. In retrospect, not worth the time and complexity its caused whatsoever, although my slightly crooked forms didn't help matters either. Oh well, live and learn.

[UtahBeehiver]

Great start, what do you envision how the oven will be used, ie pizza, roast, etc or high volume bread production. Why I ask, 6" of CaSi board is really a lot of this high tech and expensive material. 4" is more than adequate. Be sure the CaSi has a compressive strength of at least 75 psia at 5% compression. There are some softer CaSi boards out there that don't have the compression strength to support a brick oven (there heavy)

[xvandish]

Thanks! Sure, thanks for pointing that out. I went with 6" as I'd like to fire the oven over the weekend and then use it throughout the week without having to re-fire. I'm imagining heavier tasks closer to the firing day (roasted veggies, fish, etc) and lighter tasks by the end of the week like warming up bread. And for intended use on the firing day, any and everything! Once it's built we'll probably adapt our cooking to the heat patterns during the week. Especially looking forward to using the oven during the summer, so we don't have to turn on the indoor oven/stovetop and heat up the house/kitchen.

I bought my board from Skyline Components and just checked their spec sheet, they list "Flexural Strength" for my board at 0.5 MPa which comes out to ~73PSI, which hopefully is close enough. One thing I'm regretting now is not getting the bio-soluble equivalent which actually costs the same. If you're interested I bought the B12T50A board listed here - (spec sheet link is at the top of that page too).

[Buzzard Bluff]

Looks like a lot of thought went into your design and planning. It will be fun to follow your progress.

[xvandish]

Looks like a lot of thought went into your design and planning. It will be fun to follow your progress.

Thanks Buzzard! It will be fun following yours as well.

Update - making decent progress on the internal framing, re-did it since I wasn't happy with the first attempt.

Before I pour the hearth I've got to: finish up the leftmost portion (out of frame) of interior framing, do the exterior framing which will take some time since I have counter and bar sized overhangs), lay down & cut the rebar, create a form for the sink that's going in on the leftmost side, cut the pvc for the weep and faucet holes aaand do some sanity checks.

Gonna be a full day tomorrow.

[xvandish]

I finished up the internal framing and started cutting the hardieboard and the external framing.

What would you guys recommend for covering the non-filled CMU holes? I've run out of concrete bags, and don't think I"ll get enough new empty bags to fill as I pour the hearth.

[Gulf]

Beer cans have been used by some. Just about anything can be used to keep from wasting concrete. Fill the holes up mostly with empty bottles and cans. Then just use a small amount of paper to seal off the top block.

[xvandish]

Thanks Gulf for the tip. Sorry for the late response. I ended going up with rocks, plenty of them here in AZ. Big rocks at bottom, finer on the way up. Worked well enough.

The heart is now poured! I finished pouring it Monday night, 30ish 80lb bags of concrete, took me about 7 hours solo. Still standing and looking good enough! Finishing the outside framing took forever - I added a bar overhang and some overhangs on the pizza oven side and that added lots of complexity in lots of places, plus even with best efforts the lumber I got had warps and curves that made leveling rough.

I sealed everything up with a combination of caulk and silicone sealant, which seemed to work ok, no leaks on any side, and I had some decent size gaps between cement board and block edge in places. I went with 3 weep holes on the right, and the sink form is 3" from edge, with faucet/soap-dispenser cutoffs 1" from edge of form.

[xvandish]

Been working slowly, putting together the oven floor now. The hearth didn't end up completely level, so leveling and setting each brick perfectly is taking forever, maybe I'm being a bit too much of a perfectionist here.

To work during the rainy season I cut the insulation and planned/cut the floor inside the garage, then moved everything outside. Moving things outside, then re-building the floor has been enough of a hassle that I wish I'd just relaxed during the rain and then started work outside. Oh well..

Details:
planning a standard 12"ish tall inner arch, at 20" wide. Adding a 1" recess on each side for the door, and then a flared opening out to about a 26" wide outer arch. Going to use half-height soldiers standing outside of the floor for the dome.

I'll add some pictures tomorrow.

[xvandish]

Pictures of the process since march! I've done the following
1. Cut out the ceramic fiber board to size (in the garage, since march was rainy)
2. Lay the brick out in a herringbone pattern
3. Cut the floor to shape. I'm doing soldiers on the outside of the floor, so cuts cuts to size took a bit. I tried for a 45deg angle for the bricks.
4. Take all the brick off, then cut out the rest of the foamboard to the same size, using the initial as a template
5. Move the ceramic fiber board to the countertop, lay it on top of some ceramic tile
6. Move all the bricks out to the counter, recreate the layout and level each brick. Getting things level here was really, really, not fun, but happy with how it turned out, you can barely feel most of the seems.
7. Cut the soldiers. I went with full-height soldiers. I know they'll probably need extra reinforcement, but I really like them.

I'm making my IT tool right now, once that's made I'll make sure the soldiers are in the right place, and get started with the mortar.

[xvandish]

More photos. Sorry they're out of order, looked for a bit at fixing it but eh.

[Giovanni Rossi]

Making progress!
I found adding the pics 1 at a time was the only way I could keep them in order.

[xvandish]

Thanks, getting there Giovanni! I'll upload some progress next week once I can format/crop my iPhone pictures.

A question for you all - On my 3rd chain I've got 2/3s done, the middle and right parts. But I got careless and right part is way out of level with the middle (bubble over the line on level). Should I make the left part of the current course level with the right and fix the middle in the next course? Or make the left of the current course level with the middle, and then fix the middle and left in the next course? Thanks.

[Giovanni Rossi]

I'm hoping your high point is the middle so you can just add a little more mortar on the sides where it will be less noticeable but I think you're describing the opposite. Either way though, and depending how far out you are, you should make the adjustments over 2-3 courses. Again, depending how far out you are, I would be inclined to slowly ease the high section with a grinder, wet sponging with each pass.

There are members with much better masonry skills than I possess and may have a better solution. Hopefully one will see your question soon so you don't get stuck on this too long.

[xvandish]

Giovanni, since apologies for the late reply! Work and travel...

I decided to go the brute way and mostly undo the 3rd chain, I was really unhappy with it. Took some time to chisel the bricks out of position without weakening the ones below, cleaned up the old mortar, then slowly re-did the course. This holiday weekend hopefully I'll get the first arch up and continue on.