Firebricks - are 8x4 ok instead of 9x4.5?

[PizzaIdiot]

I've been infected with the wood fired oven virus!
I'm looking at building a 42" oven,but probably won't start until after New Years 2011. It'll take a couple of months to get it all planned out (yeah - I'm an engineer) and get my wife convinced that the family really needs one.

I'm just outside Greenville, South Carolina and I'm having problems finding 9x4.5x2.5" fire bricks. The only option available so far are 8x4x2.25." Thinking about the thermal mass, the 1/2 bricks that would be used in each course will result in a wall thickness of 4" rather than 4.5" - about 10% thinner.

At first thought I don't see it as problem. Am I missing something?

The other problem with the thinner bricks means I'll need to further adapt the wonderful work and drawings I'm seeing here.

Thanks, Jeff

[RTflorida]

Re: Firebricks - are 8x4 ok instead of 9x4.5?

No problems. The bricks you have found seem VERY close to those that I used. Actual dimensions of mine vary about 1/8" from the 8x4x2.25. Seems no 2 bricks were exactly the same. I used the cut to fit method, so I didn't really incure any more problems than I would have if using 'perfect' bricks.

One last thought, my bricks came from Carolina Brick....a plant in S. Carolina. May explain why that is all you can find - they may be a major supplier here in the east.

RT

[GianniFocaccia]

Re: Firebricks - are 8x4 ok instead of 9x4.5?

I wouldn't worry about it much. A large number of builders coat their finished domes with a thin shell of refractory mortar designed to strengthen the dome and contribute additional mass. I'm sure you could match or exceed the mass of others' 4 1/2"-thick domes this way.

[Neil2]

Re: Firebricks - are 8x4 ok instead of 9x4.5?

"It'll take a couple of months to get it all planned out (yeah - I'm an engineer)"

Don't do too much planning, it takes the fun out of learning on the fly.