Corner Build Foundation Question

[ralogan55]

Let the games begin.....

After determining a corner build for the Pompeii is the best option for me I looked on pp. 17-18 of the Pompeii Oven Instructions regarding the foundation and am still a tad confused. None seem to equate to a 36" or 42" Pompeii oven that I read so much about.

If I subtract 9" from the exterior dimensions I come up with interior oven sizes of 26.5", 31.0", 34.5", and 40", respectively. I understand that the 36" oven isn't exactly 36" - more like 35.6" (or something like that, but not 34.5"). Or am I wrong?

Egalecki built a 36" on a 64"x64" corner build, but there doesn't seem to be much room left for an enclosure should I go that way.

I have enough room to build a foundation of 74" on the long sides and 51" on the short sides (plus the 45 degree foundation angle in front). That should be enough for a 36" Pompeii, but what about a 42"?

I tried laying it out on a grid as suggested, but there wasn't enough room for a 78" depth.

I don't see enough discussion (or I'm dizzy from all the reading) on the subject so I need some help.

Thanks.

[fxpose]

I understand space is extremely limited in your situation but have you thought of just laying the hearth slab and simply building whatever size dome would fit within? That is the route I would take if I were faced with that situation, letting the limited space dictate the maximum size of my oven.

[ralogan55]

I sure did and in absence of any better advice that's probably what I'll do.

I'm just under the impression that things come together easier with a 36" or 42" oven (ie, even number of bricks, material list is done already, etc.).

I'm sure I could figure things out with a 39" or 41" oven, but why make more work for myself unnecessarily.

Some things can be costly (time and money) to correct. Since there's a wealth of expertise out there I'm asking first. There's a name for the other kind of people (fool).

Thanks.

[Les]

Originally Posted by ralogan55

.

I have enough room to build a foundation of 74" on the long sides and 51" on the short sides (plus the 45 degree foundation angle in front). That should be enough for a 36" Pompeii, but what about a 42"?

I'm not quite visualizing your set up - can you post a rough sketch of your corner area?

Les...

[ralogan55]

My jpeg photo files are too big and I can't attach an Excel file so I'm SOL for right now. Let me work on it. Thanks for the offer.

Rick

[Les]

Do a crude sketch using paint - should come through for us to see.

[ralogan55]

Wow, I didn't know I could cut-and-paste from Excel into Paint (duh!). I guess I learn more from FB than just oven stuff.

The first attachment is my layout that I built in Excel. It shows my foundation size, block layout, and rebar config. I have a foundation of 74" on the long legs and 51" on the short legs (plus the front angle) less 2" setback on all sides for the block.

The second is a new photo taken this morning of my oven site in the corner of my backyard.

I kinda over-excavated, but I have 6'5" to work with on the right long leg, but are using 6'2" and 8' at the top leg (and using 74" here also).

This corner isn't a 90 degree corner and the fence (at the left) diagonals pretty quickly inward and has created some problems in placing the foundation concrete forms.

Any comments or observations would be appreciated. Thanks.

Rick

[Les]

It looks to me like you can build a 42 inch. You will need to do an igloo instead of an inclosure. You will also lose the prepping area in front of the entrance, but it seems like a small price to pay for the larger size.

The numbers I used are:

42 inch inside diameter
9 inches total brick width
6 inches of insulation (3 on a side)
2 inches for cladding (1 inch on a side)

Les...

[ralogan55]

Thanks, Les.

I was just looking at gjbingham's corner build (which you "consulted" on) and learned some things (as always).

He had a 56"/40" +/- stand and ended-up with a 37" oven which created/required a cantelever in the front.

Your measurements from the last post seemed to be from side-to-side, which confirms my calcs (except for the cladding). But my bigger problem is overall length.

According to page 13 of the Pompeii Oven Instructions the all-in length of an enclosed 42" oven is 78". With a 70"/51" stand (and according to my calcs) I have 82.65" (diagonally) from the far corner (upper right) to the center of diagonal front (lower left). Shouldn't I have about 4.65" to spare (length-wise) with an enclosed 42" oven?

Geometry & Trig weren't my strong suits so I may be missing something here. I would prefer to have the option of an enclosed oven unless that's absolutely not possible.

What am I really gaining in having a 42" vs. a 36" oven (other than 6") from a practical standpoint?

Thanks again.

Rick

[dmun]

Geometry & Trig weren't my strong suits so I may be missing something here. I would prefer to have the option of an enclosed oven unless that's absolutely not possible.

You can do an enclosed oven in the same footprint as a igloo if you get creative with your metal studding. You can skip the sill plate all around, and just secure it to the stand in the corners, and then tie it together higher up when the dome curves in.