Dome wall thickness question

[fxpose]

Hello,

I need to completely confine my oven, including vent and entry, within the 48" diameter corner hearth slab pictured below and would like to squeeze in as much floor space as I can.

So this is what I'm thinking:

I can build a 3" larger oven (35" vs 32") by using bricks cut down to 3" instead of the usual 4.5". I don't plan on using a soldier course.
I understand I will end up with less thermal mass but is this acceptable?

If this is all right should I keep the entire dome wall thickness uniform at 3" or can I use 4.5" bricks for the upper courses?

Or is this a bad idea and I should just stick to the 4.5" wall thickness and build a 32" oven?

Thanks!

EDIT: On second thought, using thicker courses on top of 3" lower courses may be a bad idea, structurally. I remember reading somewhere about the line of thrust.

[olddude]

like this

also if you stand first corse on end you will get more usable area for bread and wood

just my thought's

[Les]

Originally Posted by fxpose

I understand I will end up with less thermal mass but is this acceptable?

I see no reason why it won't work. The cast ovens are thinner than that and I believe David built his 2.5 inches thick. I personally would sacrifice the mass for the larger space.

Les...

[olddude]

that pic sucked try this never mind lol

[Neil2]

32 inch is a very usable oven size. If it was me, I would opt for the thicker 4 1/2 inch mass. This will make the oven a bit more versatile - like slow roasts 24 hours later with only the initial firing.

[RTflorida]

I'm with Les on this one, go with the added space. My oven is 36" and is perfect for my family, but I really would not want anything smaller - just makes the cooking harder if you are trying 2+ pizzas or multiple pans when roasting.
Good insulation all around should allow roasting the next day without issue. Be sure to build an insulated door if you want that capability.

RT

[nissanneill]

fxpose
I would be tempted to go 3" bricks for the first few courses and then increase this to the thicker to increase the thermal mas and 'usability' of the oven. Just make sure that the strength and integrity of the oven is not compromised in needing to apply buttressing to the thinner walls. I have a 40" Pompeii and would not go smaller. This is a little too small for the odd occassion.

Neill

[fxpose]

Thank you all, for your replies! They all make good sense but I'm still torn which way to go.

I figured 3" was fine because most cast ovens I've seen all seemed to have thinner walls as Les mentioned.
I also decided I will use a soldier course, after all, to maximize floor space.

As far as the shallow entry goes, it will be rectangular with a flared side wall opening.

George

[dmun]

I figured 3" was fine because most cast ovens I've seen all seemed to have thinner walls

They also have far fewer pieces to expand, contract, and crack. That said, I have a thin wall oven and I don't see any real advantage to it. If it's just the size of the dome, you can thin the dome walls where they intersect with the enclosure.

[fxpose]

How about 3" thick walls, bottom to ceiling, and adding some layers of home brew mortar on the upper half of the dome to increase mass?