will these bricks work ?

[ronbyrne]

i can get 300 firebricks for good price but they are 4.5 X 9 X 1 inch. So i will need to cut in three to get enough to build oven BUT that will leave me with a thickness of 3" is that eneough thermal mass ?

[FrankT]

You might need more than 300...
I used 9x4.5x2.5 bricks, 224 bricks to make my 42".
224 includes the hearth, landing, vent arch and the dome.

[GianniFocaccia]

These are firebrick splits, which will require more mortar and sawcuts than if you used standard 9x4.5x2.5" firebricks. If you don't mind the extra work, I think the look of an oven made with these would be fantastic. There are plenty of precast ovens that are less than 3" that work great. If you can possibly swing it though, I think you'd enjoy the heat retention benefits of a 4" dome, especially in cold weather. Just my $.02 worth.

John

[fxpose]

Yeah, the dome interior would look awesome with splits.
Around here, splits cost just about the same as full sized firebricks so using them is not at all practical.

[dmun]

Three inches of thermal mass is ok, but as a builder of a thin dome (2.5") I can attest that thin domes are more prone to cracking. It's also not that much of advantage in heat up time. I'd use the half bricks to build your dome if at all possible.

[brickie in oz]

Cant you just add more mass with house bricks outside of the fire bricks if needed?

[Lburou]

Originally Posted by FrankT

You might need more than 300...
I used 9x4.5x2.5 bricks, 224 bricks to make my 42".
224 includes the hearth, landing, vent arch and the dome.

Assuming FrankT is correct, you'll need about one hundred regular sized bricks to complete the build. Just put them where the experts say you need them the most. But, definitely use/recycle the smaller bricks. I say yes to recycling bricks or anything else when you can. dmun could probably advise you on the best curing strategy and mortar content to minimize the cracking he experienced