# Forum Home Renovation Brickwork  Cutting firebricks

## jimfish

I'm building a pizza oven and am going to use refractory bricks for the base over calsil insulating board and solid clay bricks for the dome. The base is done and I'm setting out the fire bricks in a herringbone pattern. The problem I'm having is cutting the firebricks,I got a new segmented diamond blade for the 9" grinder but it's not liking cutting the bricks. Short of hiring a brick saw does anyone have any tips ?

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## Marc

I have never cut firebricks but this guys say their wheel are made for them ... (?) Austsaw Firebrick Cutting Blades | Circular Saw Blades for Cutting Ceramic Refractory Bricks 
As far as pizza oven, remember that you are not building a kiln to melt metal so refractory bricks are overkill. You are going to pump it up to 200 or 250 C at the most. What you want, despite all the information to the contrary on the internet, is not insulation but thermal mass. 
You want your oven to get hot and stay hot for a few hours even when the fire has died down or even after you sweep the ashes out. 
So you want a base and a dome that stores a lot of heat. 
All the pizza oven I have ever built were made of solid clay bricks, base and dome, set in clay mud, and rendered with a generous coat of the same clay.

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## jimfish

Thanks Marc , I was going to use solid clays all through but the bricks I've got are odd shaped and would of been to hard to get a flat tight floor. The diamond blade goes through the clay bricks like a hot knife through butter. The brickies are on site at work atm so I think I will take the bricks I need cut into work on Monday with a slab of tradies currency and get them to cut them. Where did you source your clay for your mud?

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## Marc

Diggin a hole in the ground, then put the soil in a pen and get the kids to trample on it with a bit of water.   :Smilie:  
Clay pavers make for good pizza oven bricks. 
A lot of cuts though. Being that I am a bit of a gadget addict, I actually bought a brick saw for this purpose from Cash Convertors.  :Shock:

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## PlatypusGardens

Looking forward to pics of pizza oven    :Smilie:

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## Moondog55

I don't see the need to cut the firebricks if you are using them for the base

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## jimfish

Progress so far.

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## PlatypusGardens

Ooo nice    :Smilie:

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## Micky013

Keep them coming please  :Smilie:

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## jimfish

Ok but it's going to be slow progress I'm afraid.

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## Mark CH

G'day Jimfish,
Glad to see someone joining the pizza oven fraternity. I built mine 4-5 years ago and we love it. Very nice brickwork on the base, mine looked like a monkey having a fit laid them but I rendered over the top so all good. I used Hebel for the base rather than a slab and it's held up really well.
FWIW I have to disagree with Marc about not using firebricks. I heat my oven to around 450-500 C then let it drop to pizza cooking heat (300-350 C) and can cook 3 pizzas in 5 minutes for 2+ hours due to the retained heat in firebricks; something that standard bricks simply can't replicate. Depends on what you want to do, I guess. If a pizza party is all you want then reds and clay is fine, if you want more flexibility, then I'd recommend bumping up the 'ingredients'. 
To make all my cuts I set it out like you, worked out all the cuts and hired a brick saw from Kennards. I cut most of my dome bricks into halves and some into thirds for the top of the dome. Got it all done in an afternoon. I also bought a diamond blade online for my circular saw for a bit of trimming that I wanted to do during the build.
In order to help retain the heat, you should insulate. I would recommend checking out Forno Bravo( www.fornobravo.com ) that has a heap of resources and advice.
depends what you want but comparing to a friends oven which is made from reclaimed reds and clay, mine retains heat better and uses a lot less wood to do a cook. I can cook pizza at lunch, a roast at dinner and retain enough heat to bake bread the next morning.
Anyway, hope yours is progressing well and I too look forward to more photos.
Cheerio,
Mark

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## jimfish

G'day Mark . I've been wanting to build a pizza oven for some years but never seemed to find the time . I downloaded the plans from forno brava some time ago and I think I have a good idea on how I'm going to go about it. We want to use the oven for pizza , roasts and bread but at over $6 a brick here in Tas the budget doesn't stretch far enough to build the entire dome out of fire bricks. The dome will be insulated and rendered so hopefully we will still get decent performance. Enjoying the process so far and looking forward to starting laying the dome on the weekend.
Cheers Jim

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## jimfish

1st course cut and muded in

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## PlatypusGardens

Looks good.  
So how did you end up cutting the bricks in the end?    :Smilie:

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## jimfish

Turns out a mate has a brick saw and doesn't need it so I've got it for the duration.

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## PlatypusGardens

> Turns out a mate has a brick saw and doesn't need it so I've got it for the duration.

  Awesome   :Smilie:

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## jimfish

Productive day today. Tomorrow I'll form the door opening arch and hopefully another course

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## PlatypusGardens

Looking good 
This sort of stuff is way beyond me.
I'd start off ok, but once I get to the top nothing would line up   :Unsure:   
Not sure about the garden gnomes, however....

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## jimfish

Haha the gnomes appeared from under the shrubbery that was formally in that garden bed. Must have been abandoned by the previous owner. It remains to be seen how well everything will line up as I've only been building by eye and ruler. Pretty happy so far

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## Moondog55

Nice work and I can see why you wanted to cut the firebricks
Is it going to be sand filled and clay plastered now or will it be bricks all the way up?
I actually like the gnomes

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## jimfish

No going with bricks all the way, I'm going to use a beach ball as a form to hold the top bricks in place. Then cover with insulation blanket and chook wire and render.

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## jimfish

Have been struggling with the transition frome dome to arch, in the end I just started cutting bricks and will keep cutting till all the gaps are filled.

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## PlatypusGardens

Winning so far!   :2thumbsup:

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## Marc

Couple of questions Jim:
What are you using for mortar?
I notice you left the wooden wedges in from the outside. Are you going to point the gaps with the same mortar you used inside?

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## jimfish

Hi Marc , I have used visouvious air set mortar for the inside. It is a refractory mortar only recommended for up to 3 mm gaps..the outside I will use a lime based mortar with a little cement and fire clay( if I can find any down here) to point it up.

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## jimfish

Finally after work commitments, Christmas and daughter providing us with our first granddaughter I have some time to get back to the pizza oven.

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## Marc

I thought you had baked your Christmas roast in it already ... keep the photos coming !

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## jimfish

That was the plan but unfortunately I run out of time to get it built.

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## PlatypusGardens

Looking good.   :Smilie:

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## jimfish

And more today.

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## Uncle Bob

That's a very nice brick igloo you're making there  :Wink:

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## Marc

Flue at the top?

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## jimfish

No will be on the front of the inner arch Marc

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## Marc

Mm ... I always thought that having the flue at the front makes the construction of the oven so much complicated and the use more restricted. Anyway you are committed now.

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## jimfish

Would definitely be easier to put the flue at the top but I think heat loss would be a problem.putting it at the front shouldn't be any different to the rest of the build, cut brick mud it in place then repeat😀

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## Marc

Ha ha, yes, you have done the hardest part already.
There are advantages to a flue at the back (not at the top), one third down the back. No need for such complicated front opening structure and a controlled flue at the back gives the cook a bit more comfort and allows to direct the smoke if that is required.

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## jimfish

Had to use sand as a form in the end which while it worked it meant that it was impossible to check how flush the bricks were on the inside and some didn't quite line up as I would of liked.
I may take the diamond disk to the inside tomorrow to tidy it up.
It's now time for a cold cleansing Ale 👍

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## Marc

Looking real good there Jim !!

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## PlatypusGardens

Interesting....so it's just held together with a little bit of mud and gravity at the moment....?
Will it be covered on the outside, as in "rendered" or will the individual bricks be visible like on a brick wall with mortar in between?   :Smilie:

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## jimfish

The mortar I used P G is an air set mortar which is very sticky and goes off quickly allowing me to lay several courses without the worry of it sagging or falling in. 
Started pointing the outside of the bricks today.( horribly slow process). Once that's done I will brick up the outer arch and chimney. It then gets wrapped in ceramic insulation blanket and chicken wire and several coats of a vermiculite render which also insulates the dome then my daughter is going to cover with a tile mosaic pattern.

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## PlatypusGardens

I see. 
Very cool, but I think I'll stick to my steel plate fire buckets.   :Smilie:

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## jimfish

The never ending saga continues. Finally got a nice sunny day to coincide with a day off so the front arch and chimney is on the agenda today. Photo update at the days end .

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## jimfish

Run out of time today but only one more course on the chimney and a few bricks to trim up to the chimney then render the dome.

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## PlatypusGardens

Very nice I like it a lot

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## jimfish

Ceramic fibre insulation and first coat of vermiculite render.

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## jimfish

And the bricklaying is finally done. Now just render to finish.

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## phild01

> Ceramic fibre insulation and first coat of vermiculite render.

  Interested in how this is done, and the material supply?

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## jimfish

> Interested in how this is done, and the material supply?

  Hi Phil 
It's a pretty simple process. The blanket came from a company that builds kilns and supplies brick oven components. The blanket is offcuts and we're basically installed in layers overlapping the previous. I ended up with 4 layers making it around 100 mm thick. It is then covered with 4 25mmish thick coats of a 10 - 1 mix of vermiculite and cement and once dry will have a coat off acrylic render to seal it.
If all goes to plan the oven should hold enough heat to bake bread the day after using for pizza.

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## phild01

Thanks Jim, does the vermiculite naturally give that rough finish, or is that technique?  Never seen it done before.

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## jimfish

It's the vermiculite Phil, as it's got minimal cement in it there is no slurry to get a smooth finish. The vermiculite is basically another insulation layer and to form a solid dome over the blanket for the acrylic render.

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## jimfish

Acrylic render to base done and 4th and last coat of vermiculite to dome. Three or four days of drying and then time to start lighting fires to ensure all is dry before acrylic render to dome.

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## Uncle Bob

Wow, nice job Jimfish!

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## jimfish

And today we have fire !

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## jimfish

And a door .

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## PlatypusGardens

Beer and pizza next?  
top job.
love it

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## PlatypusGardens

Where does it draw the air in?
is there an inlet at the back?

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## jimfish

Thanks , had a few beers last night while watching some bread bake. Draws through the front opening. The door is only to keep heat in once the fire is done cooking pizza. Kept a smallish fire going all day yesterday to cure the oven, another smallish one then time to crank them up a bit.

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## Armers

looks awesome mate! Very jealous!

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## SlowMick

amazing work. serious dedication to baked goods.

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