Using non-tapered bricks

[yoboseyo]

I am planning on using regular red brick, due to the difficulty of acquiring firebrick. I am starting to get the plan down pat, but I still have a few concerns.

If I lay the bricks on the right angle and fill the gaps with mortar, then the only issue I foresee is that there's less thermal mass overall due to more gaps. Is this a big concern?

What other considerations to this approach have I not taken into account?

Also, if I'm doing it this way, do I need to leave a mortar gap on the inside? or can I just fill up the V gap on the outside?

I'm not looking at cutting bricks into a taper, as that's too onerous for what I'm trying to do, even though I've seen a lot of recommendations of doing it this way. If it's highly preferred, I'll look to source tapered fire brick

[david s]

You can probably get away with using red house bricks for the dome, but you need firebricks for the floor. You can have the brick edges touching on the inside so no mortar is visible. This is useful as you have no joints to clean up. Filling from the back with homebrew will result in little difference than cut bricks because the density of homebrew is not too much different from brick.

[yoboseyo]

You can probably get away with using red house bricks for the dome, but you need firebricks for the floor. You can have the brick edges touching on the inside so no mortar is visible. This is useful as you have no joints to clean up. Filling from the back with homebrew will result in little difference than cut bricks because the density of homebrew is not too much different from brick.

thank you! I am, indeed, going to use fire brick for the floor.

What's homebrew?

also, if my bricks are 230mm*115mm*75mm should I cut each in half for dome-building?

[david s]

Homebrew is the cheap, make yourself mortar used for ovens that most builders use. It works extremely well for the temperature range we fire to.
3:1:1:1 sand, Portland cement, hydrated lime, powdered clay.
most builders cut the bricks in half. If you make the cut on an angle, one side of each half brick is done in the one cut.