2 Brick Questions

[thebadger]

Gang,

My very first post. I was thinking about buying a pre fab oven kit and then found this site!!! I'll still be making some purchases from the FB to aid in the construction.

The boss says I'm not allowed to start until next year but she didn't say I couldn't get everthing ready.

Just a few initial questions:
1) found a local supplier of fire brick - yellow - "correct" size but he isn't sure if it's low/med/high duty. He charges $1.15 each. Don't want to build with the wrong stuff - is this okay?

2) Regarding the soldier course :
a) It sits on the brick base and not the isol board or concrete/vermiculite base?
b) It doesn't look like you mortar the soldier course to the brick base on the bottom - does it just "free float?"

Thanks
Dick
thebadger
Cincinnati, Ohio

[maver]

The yellow firebricks you found are probably the correct ones - they should be pretty heavy - about 9#. If they are light then they are insulating firebricks which you do not want.

My soldier course sits on top of the insulation. Do the current plans suggest placing the soldier course around the insulation? You want a layer of insulation between the walls of the oven (soldiers) and the concrete hearth to avoid heat loss into the large concrete heat sink that is the hearth.

And yes, the soldiers can be free floating (although they are not free once they have been mortared in to their neighbor soldiers and weighed down by the massive dome).

[james]

Hey Dick,
Welcome aboard.
You have two choices on where you put your first course of dome bricks -- both of which definitely sit on the insulating layer. You can either build the dome directly on top of the cooking floor, or you can cut your cooking floor into a round shape, and set the dome on the insulation layer.

I think it is easier to build the dome on the floor, but the oven will be a little more efficient if you build the dome around the floor. The better precast ovens (all of ours) are designed with the dome around the floor.

Maver has it right on your bricks. As long as they are heavy (not insulating bricks) they will be fine.

If the project ever looks daunting, you can always buy an FB precast oven.

James

[dmun]

I built my dome on the floor. One consideration is if you are going to make an igloo enclosure, you may want a smooth circle at the bottom. It is not a necessity: you can raise the floor level up above the ragged edge of the floor. Remember: the first pompeii plans presumed that people would be cutting their bricks with a brick set: it was meant to be a minimal-cut operation.

[james]

David,
That's a good point. You can go as elaborate or simple as you want -- with more, or less cuts, and more or less accurate cuts. You get to pick your own level.
James

[thebadger]

Thanks!

I thought it looked like the soldier course "rested" on the bricks but wanted to check. I'm sure I'll go with that approach. Don't worry James I'll be making some purchases from the FB store. The problem with ordering the pre cast is the shipping (in addition to the base cost). These ovens don't seem too prevalent in the mid-west. Based on some other posts I've read it doesn't look like I need to do anything "special" for construction and could use it in the winter if I follow the advice I've read.

Dick