Oven floor brick cuts

[mleuck]

After setting up the fire bricks for the oven floor and tracing the template, what is the best way to cut the bricks? With the "rounded" cuts, they must have to be "free handed"? Looking form a good technique for this step.

Thank you

Michael

[david s]

Most folk buy or rent a brick saw. You can also get by using a large angle grinder fitted with a tile cutting diamond blade. Either way be sure to use a respirator as brick dust is dangerous to inhale.
If the dome is built on top of the floor instead of around it, then you don't have to cut the floor bricks, they can stick out past the base of the dome, just cut roughly with a brick bolster. The only disadvantage of building it this way is that replacing a floor brick (if ever) that sits under the dome wall is very difficult.

[Gulf]

Mleuck,

I did mine with a 10" wet saw. So, my advice comes from that experience. Yes, they are sort of free handed. I would describe cutting the curve on a floor brick as a series of straight cuts. However, you can simplify it by first making one straight cut across the brick on the outside of the mark. Set the waste to the side and make a couple more cuts, just outside of the mark, at angles. Sort of like shaping part of the brick to a stop sign. Now, you can start making a series of short cuts. After a couple of bricks, you will notice that the kerf of the saw blade will allow you to proceed a little ways through the brick while forming a curve. When the cut starts getting tight against the blade, you will then know to finish the finish the cut straight across to get the waste out of your way. This probably doesn't make sense right now but, after a couple of bricks, you will be a pro .

EDIT: I attached this diagram hoping to make it a little clearer

I hope this helps.

[mleuck]

Thank you very much! Your explanation and picture makes it very clear for me!

One other question..... My plan is to build a 42" pompeii. I see everyone has a template. How is the template created? I understand the circumference, but how is the opening calculated?

Thanks again for taking the time to explain the brick cutting.

[Gulf]

The width of the opening is not nearly as important as the height. I have a 44" oven. (22" dome id) My opening width is 20" wide. The height is 12.5". I could of went up a little higher with the height of my "door". The perfect number is 63% of the the height of the id of the dome for the height of the opening. In making a template, you will want to decide if you want a a flared entry or a straight tunnel. Mine is straight. But I have a large reveal which gives about as much side to side room for working the oven. You will also want to decide how deep your entry will be.

Edit: You may also want to check @JRPizza's build, and find out how far forward that he finally decided to place his inner arch. The dimensions aren't the same but, the theory behind it is.

Edit:I corrected a sentence above to read door instead of dome.

[moderator]

Thanks for posting that graphic explanation to help out mleuck, Gulf!

[mleuck]

Thank you for the information. Another question....When framing the hearth, what is the best option.... plywood or backer board for the base. The plywood is 3/4", what is the thickness of the backer board? 1/2" ?

Thank you all for taking the time to answer my "beginner" questions.

[UtahBeehiver]

Either work, but with backer board, you can incorporate in pour and leave. You do need to make sure you temp. support underneath.
I used 1/2" that overlap the wall but not covered up the cell completely so I could grout.

[valentin]

You don't need cut with such precision as the Gulf offers. Simply cut and after grind. Video of grinding

https://youtu.be/MOm7aqfpW4g

[DavidApp]

There are a lot of ways of getting the Oven floor bricks cut. They all work but some take a bit more time than others. I cut mine with a 10" Harbor Freight wet saw like Gulf suggested and it only took a few cuts per brick. The hand grinder will get it done but will take more time.

David

[JRPizza]

Mleuck, I also used backer board. I did it because it seemed to really simplify the framing process and eliminated the need for removal of the plywood after the hearth pour. I went with 1/2 inch board - I had a sheet of 1/4 but I convinced myself it was kind of thin and might have more of a chance to fail before the slab cured. Since the backer sits on top of the cinderblocks, I poured my hearth 4.5 inches from the edge so I would have a full 4 in the middle. Probably overkill but I did not want a 3.5 inch slab.

[joeykramer]

im about to use Durok, for my hearth base and plan to support it using angle iron notched into the top layer of cinder blocks.

[JRPizza]

Do you have a picture or drawing to share?

[proc]

I did the same, hardi-backer on cinder block with an angle iron in notched cinder. Nice thing about the hardibacker is that you can leave it in place and let the concrete key into the cinder all the way around the backer.

You can see it here:

https://my.matterport.com/show/?m=Byk5n8VR1hb

I did use shoring jacks under the backer board to make sure they did not sag. You can see them if you click around to the front of the base.

[joeykramer]

Here's a rough view of what I'm working with. Planning on pouring this weekend