How well would these work?

[joesn68]

How well do heavy duty fire bricks work for a residential oven? This ad is local but understand that medium duty bricks are desired. I am planning on a 42 inch oven so how many would I need for the floor if these are acceptable on top of a ceramic board base?

Large, heavy duty, hard firebrick suitable for gas kiln, pizza oven, fireplace construction, etc. Measure 13.5x9x3 and weigh 22lbs each. Approximately 105 available at 1 dollar a piece if you take all.

[rwiegand]

Given that none of the masonry supply places I contacted had a clue that there were different kinds of fire bricks I wouldn't assume that the language "heavy duty" has any actual meaning in this ad. That said, I don't know how they might differ from "garden variety" fire bricks in use in an oven. Those bricks are very large and the price is great, so I'd look hard at them.

I used about 320 4-1/4 x 8-1/4 x2 -1/4 bricks, so 100 of these larger bricks should be close to enough if you can cut them appropriately. You'll need a big brick saw.

[UtahBeehiver]

There is a difference in duty ratings, it depends on the amount of Alumina in them, the higher amount the higher the duty rating. In my case I used what is classified as SuperDuty. My bricks were surplus from a steel mill and used to line the steel kilns. Also large and thick, 6 x 9 X 3 (dome) and 6x18 X3 (floor) I had to adjust accordingly. Even though some say that super duty retain too much heat I have not had any issues. One caveat, super duty are very very dense and harder to cut and take their toll on diamond wet saw blades. I went though a dozen cheap ones. The ones I see on the KSL ad look like good potential for the floor but you will have quite a bit of cutting to use in the dome. I am I SLC so if you have any questions PM me.