Can I use clay paving bricks for my dome?

[Steve_H]

Hi all, inspired by this site I am about to start my first build.
I have a huge pile of paver bricks salaged from my old veranah floor and I was hoping to use some in the construction of my dome.
I wasnt sure if they would stand upto heat so I chucked a couple in my log burner indoors and after a couple of weeks, they havent cracked. Obviously this will save me some considerable money but will they be good enough?
Thanks loads
Steve

[nissanneill]

Re: Can I use clay paving bricks for my dome?

Hi Steve,
if they are fired clay pavers, they will be fine as they are normally fires at around 1200˚C. One of the original wood fired oven builders in Adelaide, Russel Jeavons built numerous ovens and had 2 in commercial operation in Willunga for years without problems.

Cheers.

Neill

[hodgey1]

Re: Can I use clay paving bricks for my dome?

Hi all, inspired by this site I am about to start my first build.
I have a huge pile of paver bricks salaged from my old veranah floor. Obviously this will save me some considerable money but will they be good enough?
Thanks loads
Steve

My only comment would be that when looking at the total cost of my project pushing $5k USD, that the cost of the bricks "$350 USD" was one of the cheapest parts of my particular build. If you factor in the man hours it takes to cut and set those bricks properly my advice base on those things says, only use bricks that you are 110% sure will function properly before using them.

Before all the scrap maven/junkyard dogs jump on me, "I love used" look at my build, I used reclaimed slate, barn beams and counter tops. I'm not saying not to use them, but just thoroughly research what you have before hand. Finding out later, like I've read here on the forum , that after the fact you used the wrong product and the end result is your left with a under performing WFO or worse yet one that's not-functioning or dangerous.

[cobblerdave]

Re: Can I use clay paving bricks for my dome?

G'day Chris
With most firebrick approach $ 4.50 a unit in Aust and with transport costs to anywhere outside the major cities expensive ,firebrick is a major expense.
A NEW pressed fired clay paver can be got for .50c to $1.20 locally now that's a big difference...... And to put it simply, makes the difference between it being able to build an oven or not. I say do it rather than not.
Regards Dave

[hodgey1]

Re: Can I use clay paving bricks for my dome?

G'day Chris
With most firebrick approach $ 4.50 a unit in Aust and with transport costs to anywhere outside the major cities expensive ,firebrick is a major expense.
A NEW pressed fired clay paver can be got for .50c to $1.20 locally now that's a big difference...... And to put it simply, makes the difference between it being able to build an oven or not. I say do it rather than not.
Regards Dave

Wow, that's more than double the price here. I can see why you'd want to try to find alternatives. Thanks for the eye opener Dave.

[Steve_H]

Re: Can I use clay paving bricks for my dome?

Thanks for the replies. I asked the same question in my other post (Australia) but got impatient waiting for it to appear and asked again here! there is now a question over whether my pavers are even clay, they could be concrete so I will carry out some more checks and continue on my other thread.
Thanks again
Steve

[oasiscdm]

Re: Can I use clay paving bricks for my dome?

G'day Chris
With most firebrick approach $ 4.50 a unit in Aust and with transport costs to anywhere outside the major cities expensive ,firebrick is a major expense.
A NEW pressed fired clay paver can be got for .50c to $1.20 locally now that's a big difference...... And to put it simply, makes the difference between it being able to build an oven or not. I say do it rather than not.
Regards Dave

Makes my recent purchase of 200 Arch Firebricks for $1.50 each a bargain. Must remember to pick them up Saturday week.

[david s]

Re: Can I use clay paving bricks for my dome?

Hi Steve,
if they are fired clay pavers, they will be fine as they are normally fires at around 1200˚C. One of the original wood fired oven builders in Adelaide, Russel Jeavons built numerous ovens and had 2 in commercial operation in Willunga for years without problems.

Cheers.

Neill

They may well be ok, but also they may not. Neither being made of clay and fired to a high temperature are guarantees of suitability. These pavers have been designed to be walked on not used in a kiln or oven. We used to buy creamy solid house bricks from Cooroy years ago that happened to be ok as kiln bricks up to stoneware temps (!300 C). Although many house bricks and pavers are not suitable and are likely to fail, particularly if used for the floor. By all means try them if they're free or cheap, but you have no guarantee of their suitability unless someone else has tested them.

[nissanneill]

Re: Can I use clay paving bricks for my dome?

Hi again Steve,
I use a simple method to check the suitability of the pavers within an oven by getting a rather large hammer or smaller sledge and giving the brick/paver a solid belt. If it shutters with lots of small bits the I wouldn't use them but if it breaks into a few larger pieces with just a little fines, then they would be suitable.
Russell Jeavens used 2 layers of pavers in his ovens as the top layer was easy to replace after considerable commercial use, I thought to be a good idea. You might see if you can get a copy or borrow his book, titled "Your brick oven, building it & baking in it" ISBN 1 9049443 25 X printed in 2005 by Hyde Park Press in Adelaide.

[david s]

Re: Can I use clay paving bricks for my dome?

Hi again Steve,
I use a simple method to check the suitability of the pavers within an oven by getting a rather large hammer or smaller sledge and giving the brick/paver a solid belt. If it shutters with lots of small bits the I wouldn't use them but if it breaks into a few larger pieces with just a little fines, then they would be suitable.
Russell Jeavens used 2 layers of pavers in his ovens as the top layer was easy to replace after considerable commercial use, I thought to be a good idea. You might see if you can get a copy or borrow his book, titled "Your brick oven, building it & baking in it" ISBN 1 9049443 25 X printed in 2005 by Hyde Park Press in Adelaide.

Neill, that may be a reasonable test of the pavers strength, but it does not tell you anything about the pavers thermal shock characteristics. Generally the more vitrified the clay is the stronger it will be and the higher fired it is the more vitrified it will be. But an open clay body, fired to a low temperature has much better thermal shock characteristics than a high fired one even though it will be considerably weaker.

[nissanneill]

Re: Can I use clay paving bricks for my dome?

To a certain degree David, I agree with you, but with the thermal shock on a lower fired brick/paver and a more absorbent material (although minimal) the more proned to is to suffer from surface breakdown and drop small brick particles. My experience over the years is to see that clinker bricks (those receiving the maximum heat from the firing process with in the kiln) stands up to regular heating/cooling in an open fireplace than the lower fired samples. This is also seen in "low fired bricks" that fret away over the years with weather conditions only, no fire nor heat to accelerate the process. I have been down to Russel's Pizza Restaurant, observed carefully his 2 ovens and they work exceptionally well at a fraction of fire bricks.
I also agree that ire bricks are the preferred build material, but to build with the best alternative or not to build at all, that is the question!

[cobblerdave]

Re: Can I use clay paving bricks for my dome?

http://www.fornobravo.com/forum/f6/budget-build-36-a-19911.html?highlight=Budget+build

G'day
The link above is a pressed clay paver build.
What I would like to point out is that he used the " hit with a hammer " test and bypassed some possible bricks. Unfortunately it came out out the end that he was using a sledge hammer and a solid cement surface underneath. What can you say If you do apply this type if test to a brick a soft under surface like a bit of grass covered surface....I recon I could powder a firebrick easy the same way.
A lot of secound hand brick is not suitable just for the fact that 9 times out of 10 it's stored out of site out of mind at the back of a shed. Soaking up water covered in moss.... Certainly deteriorates them.
With a New pressed fired paver at least you have product that hasn't suffered from the elements.
In Brisbane for anyone that's interested.
There is Clapave in Dimore (Ipswich) they make a 29 per cent fire brick. They also produce a white fired brick common. Their pressed clay pavers are fired to 1200C.
Warrick on the Darling Downs they make a brick common that is reputed to weigh more than a Dinmore firebrick. Personally I have never laid my eyes on one of these monsters. So if you use these please tell me.
Recycled . There is one that stands out. Its a light red brick brick common used in the 50s 60s on a lot of the public buildings. An example for those who care to look is the C of E church in Wynnum. My diriveway is paved with these but of course I would not use now as 16 years in the ground.. Perhaps not.
My own oven dome is built of "light duty firebrick" the rest a mix of whatever I could lay my hands on.
If I was to build again... First I would build... Hey its a lot of fun .. And you get to eat from the results..
Secound i would build with whatever I could... A budget build.... A hearth floor of firebrick splits and a dome of Fired ClayPavers.. If I won Lotto .. That builder would be kept busy with instructions
As always
Regards dave

[david s]

Re: Can I use clay paving bricks for my dome?

Yes Dave you are correct. A fire brick is generally far easier to break up (weaker) than a solid house brick.The reason is that the house brick is partly vitrified but the firebrick far less so because it contains less fluxes that help the silica start to turn to glass. It is the composition of the clay body that gives it the thermal shock characteristics rather than its raw strength. That is why I question the efficacy of banging a brick with a hammer to test its thermal shock characteristics. Taking this a step further, an insulating fire brick has even better thermal shock characteristics than a dense firebrick, but will crumble really easily if hit with a hammer.
African and South American low fired pottery (around 600 C) can be placed directly on a stove. While similar stoneware fired(1200 C+) pottery won't cope.You won't find any commercial bricks fired that low, because as they are designed for houses they want them to be partly vitrified so they are partly waterproof, but still a bit porous. It is the thermal shock characteristics that are important for our ovens and the firebrick is the logical solution. Most solid house bricks should be fine,
but some will not be and you won't be able to tell by smashing them.

[oasiscdm]

Re: Can I use clay paving bricks for my dome?

hey Dave

I will let you know what happens to a Claypave paver yes fired to what you said 1200c I will be getting it re-fired once I play a little.

Fingers are crossed

[david s]

Re: Can I use clay paving bricks for my dome?

If it is a clay paver why are you refiring it? It should already have been fired, most bricks to around 1100 C