Non-square bricks

[guiriguiri]

Hi all, another Saturday back at work on the oven.

I'm trying to get all my cooking surface bricks laid to mark exactly where I need to cut but am running into the problem that very few of my fire bricks seem to be square on all 4 corners. Obviously, this leads to compounding problems and eventual (small) gaps. Is this common and just a necessary headache or should I hold out until I can get some new fire bricks from a different source? I have to get more for the dome anyway, but if I do that, I can't continue until next Saturday as all the supply companies are closed.

[Gulf]

If they are new brick, and are standard 4.5" X 9" fire brick, then they should be pretty even in size and also square. I would hold out for a more even and well fit floor.

[dakzaag]

Firebrick are a manufactured item basically pressing the ingredients into a mold with high pressure and then fired. In the masonry world, they are the most consistent square brick available, Either you have some odd firebrick or your base is not level. A typical floor can be laid out as fast as you can pick up the brick normally. If you are using second hand brick for the floor, you might want to rethink this decision. Any uneven brick in the floor become little lips that the pizza peal catches on. Food and ash will also build up in any crevasses. Use brand new brick for the floor and save the odd brick for the dome. The picture below is a new floor with new brick. As you can see, the brick match up pretty close.

[dakzaag]

Let me revise my statement. I recently asked my local brick yard for a quote on firebrick. 1.99 they said, so I asked who the manufacture was...Belden came the reply. I spent several minutes trying to convince the salesman that Belden does not make firebrick. Well low and behold, Belden entered the firebrick market about 12-18 months ago. So today I stopped by to look at the new Belden fire brick. Indeed they were nice new fire brick. No markings or name on the brick, but pallet wrap was straight Belden. Every brick I looked at had a bulge on the back side. Even had the fork lift driver move the top pallet so I could check another sample. Same thing. The bulge was about 1/16 inch. If you spooned them together, they fit nicely, but then the next brick was way off. Easily causing 1/8-1/4 inch gaps when laying an oven floor or stacking shiner style. I am almost certain the brick were seconds, but the owner of the yard said they were number 1 Belden brick.
A lot of yards carry Belden brick and this is such an easy option for the brick yard to stock a relatively cheap firebrick and avoid dealing with the other refractory suppliers who do not sell common brick. I should have snapped a picture, but I am sure this is what is going on. If you are building a standard fireplace, and stacking the brick common running bond, the back side would be insignificant, but stacking shiner style or laid flat for an oven floor and you are going to have issues.