When building the herringbone cooking surface could you fill the small triangular voids with sand (instead of cutting small pieces of fire brick) especially on the back and sides?

If the voids are smaller than 2" in length - and not in a visible area once the oven is finished, then you will be okay to fill the void with sand.

Just keep in mind, if you miscalculate - the void you filled with sand will be visible once the brick oven is in place (and impossible to move).

Cant find much info on cutting the fire brick can you help? I only found one that said use an angle grinder with masonry blade…can you post a link! Surprised more haven’t needed guidance! ha!

Hi Child of God.
If you have a Harbor Freight near by you can get a angle grinder for $15 bucks or less and a three pack of diamond blades for under $20. I bought two on sale for $9 each and have only used one for over a year cutting brick, stone and concrete block for all the backyard projects.
For the fire brick on the oven floor I found a tile saw was better because it will cut true right angles, harder with grinder and diamond blade. tile saws also come with an adjustable fance to cut the 45’s needed for the herringbone cooking surface. Good luck,
I’m attaching the ceramic blanket today. should be fun!

great! We have a reciprocating table saw with masonry blade so far…we will try that. Wasnt sure if there was a reason no one had mentioned it…and not much talk at all about cutting the brick. Is there a function of setting brick on the herringbone pattern or just for looks? I love the look but a simple brick pattern would be much easier (;

Hey Child of God -

We don’t cover brick cutting too much - since it’s kinda straight forward. And super easy. Once you get that Angle Grinder in your hands, cutting brick is like running a hot knife through butter. Dusty, Dusty Butter… So be sure to wear a surgical mask / mouth mask so you don’t inhale that dust. And always wear eye protection.

As for the herringbone pattern - It is VERY important that you lay the hearth fire brick in a herringbone pattern. As you are sliding your pizza peel into the oven, if just one fire brick is slightly elevated, that pizza peel will either stop immediately (sending a nice shock down your arm)… or it will simply break off a piece of that firebrick (a la - extremely crunchy pizza).

By placing the hearth fire brick at a 45° angle, your peel will slide along the edge of the elevated firebrick (not stopping your peel or breaking the firebrick). If you do have an elevated fire brick on the hearth, you will feel the minute change while using your peel - so once the fire is out and the oven is cold, simply use a rubber mallet to tap, tap, tap that elevated firebrick back into position.

Be sure to take pics of your project for the BrickWood Ovens Photo Gallery!!!

Welcome to the community!

Good advice has already been posted about the tool you need. (I already had an angle grinder, and I Amazon’ed my diamond blades for under $10.) The other piece of your question may be the relative complexity of fitting firebrick “parts” into the larger herringbone pattern.

Unlike with the standard bricks around your frame, and with the firebrick that will form the arch of your oven, the firebrick hearth is fit as tightly together as you can manage. They will be held in by the frame, and you want them to have little or no joint space between them.

When you lay out the herringbone (which by the way is completely FUN!), pay attention to the angle and level each brick on the sand underneath it. A mason’s line across the top, set at the 45° angle, would be helpful to get you started.

You need to get a uniform surface that is flush to your brick frame. Lay as many whole firebricks in the herringbone pattern as you can, then ensure that the entire pattern is flush and angled correctly. You’re not mortaring them in place, so you are free to redo it if you aren’t happy with it the first time.

When you have all the whole firebrick in place, you can start nipping pieces of firebrick into the voids that are left. Start by taking a firebrick and laying it where it would fall in the pattern, using the brick frame to support it. Use a Sharpie or crayon to mark the spots where it touches the frame, and a combination square to extend that line to the top of the firebrick.

Once you’ve marked the two sides, use the combination square again to draw a line on the top between the two side marks. That’s your cut line, and you’ll be able to follow it all the way down because of the side lines.

Don’t worry about the lines themselves—you’ll be cutting them away with the grinder, and any remnant will end up under the walls of the oven.

DO worry about making sure each cut piece is level with the rest of the hearth and the brick frame. Again, that’s what the base sand is for.

And finally, when you see a reference to Step 48 in the instructions, ignore it. There is no Step 48, and no need for a small bag of flour. The idea is to wedge your hearth brick in tightly, and any remaining space between the firebrick will be filled in with ash from the delicious pizza you’ll be making.

Hope this helps!

Hey, I’m at the stage of laying my herringbone pattern. I’ve seen all the posts about letting ash fill the gaps and the function of the herringbone angles dissipating linear force against the red brick perimeter. Since these bricks are virtually perfect rectangles and I have a masonry blade on the miter saw, I can get the bricks to fit extremely tight. My question is, should I get them as tight as possible or should I relax about 1/16" or 1/32" gaps here and there to allow the bricks to expand when they get hot? I don’t want my OCD to actually backfire and crack all my bricks because I fit them to tightly.


I think the answer is right there in your question, Mike. I’ve been using the miter saw too, but there is a little space between those brick to allow for thermal expansion.

Getting them fit snugly into the frame is within your reach (and your tool’s capabilities) but better to let them have a bit of breathing space.

I did find that cutting the corners off the odd bricks and making the pieces to fit the little triangle gaps was much easier with the miter saw.

Good luck with your build!


TIGHT AS POSSIBLE! Yes - there is some micro-movement during high heat (less than a hair)… but it will not effect tight firebrick.

When customers MORTAR those hearth firebrick into place… that’s when cracking occurs as they are unable to move / adjust under high-heat.

Click-and-Drop… just like driveway pavers. Nice and tight.


Hi all,

Yes I set my as tight as I could and have no problems.


6 posts were split to a new topic: Using a miter saw to cut firebrick | tips, tools, techniques