Firebrick

Look here:
Source from the Clay Firebrick suppliers listed here

If you don't find the shape you want, firebrick cuts nicely with a brick saw or a masonry abrasive cutoff disk. Be sure to wear a dust mask. You can cut out wedges and staves and conform quite decently to (singly) curved surfaces.

In the seafood plant where I work, we recently relined a large propane sea cucumber wok. The annular bottom consisted of 10 uncut bricks alternating with 10 36° wedges (5 bricks cut in half diagonally). It came out looking like a rose window in a cathedral, and no material wastage.

Hi vishwanath,

You refer to an almost 12' (~4M) chimney. Unless you are using extra large sized bricks, the normal size refractory brick in 9" x 4" x 2.5". I would choose a standard 'flat' brick with square edges and faces. What is the chimney for? Do not forget all the usual standard refractory building methods of tying-in to the other non firebricks away from the inner surface layer. Are you using ties or relying on different brick bonds to tie the structure together?

Building a 12" chimney the standard firebrick as stated above, can have each consecutive brick laid slightly at an angle compared to the previous brick. As long as the brick joints are 'made-good' with complete coverage of the brick-bed with mortar, and no voids or spaces, when these square edged flat faced firebricks are used to build such a large circle, you will hardly notice they are not curved!

Actually, even for a normal domestic chimney I have not seen much use of 'curved' face bricks. The curve necessary for your chimney would hardly be discernible anyway, so, as long as you do use firebricks, I can see no reason for not using the standard firebrick. But, as I have said the 'finish' is all important and a smooth surface with making good completed as you build, (not the next day or two) is crucial to a refractory face to allow for easier cleaning and no patchy build up of soot which can fall back down and make a mess or certainly not be nice to work with.

Good luck and please ask further questions if necessary.

Hi Babybear,

our bricklining dia is 3.9m and our specification says that below 4.5m dia shaped bricks should be used . unfortunatly shaped brick is not available than what is solution.

Hi Guest,

Is this a huge job for you? Because if the spec of a chimney states you must use shaped bricks then you have to.

I cannot see the Council agreeing to building with any other method if it is 'written in stone' that you must use shaped bricks. You and I know that there is shaped bricks out there, it just depends how close they are to you? I once had a building job where I had to use a particular type of cement. It was non standard in my area so I had to travel a round trip of 280 miles for it. It was all part of the job.

My suggestion to you, is write me a PM by clicking on my user name and write a post as usual. Tell me which Town you are in and I will see if I can find some bricks for you, OK?

But there is possible ways around this, provided you are upfront and honest with your customer and Local Council and explain your predicament about not being able to find any shaped bricks?

If you have not already started it, which I suspect you may have done, you can design it to allow for the inside to be plastered with refractory cement perhaps, though you will have to build it slightly smaller to allow for whatever the standard thickness of refractory cement is?

Or explain there is no shaped refractory bricks and would normal flat sided, square edged bricks be allowed?

The other problem may be that you have to taper the chimney in toward the top. A flat sided chimney using normal shaped bricked could be built with every other course laid the same way, but if it narrows at the top you may find the flat sided bricks may start to be laid like a corkscrew............. All be it a very large one.

Good luck and PM me.

I think I asked how tall the chimney is? I mean to say, if it is going to take several months to build there is no reason why you cannot put a special order for shaped bricks for the job?

PM me and we can discuss this further.

An interesting GA. I hope the conversation stays public, though, so we can see how all this works out.

Flat bricks will not deviate very much from this large a stack diameter. I would think that troweling a bit of refractory cement onto the back side of each brick (mounding a little in the center), and on the joints between, should seal this up pretty well. But this is only a general observation; I am not a bona fide boilermaker--just one project that came out well.

Hi Tornado,

I appreciate your reply post and GA, thank you!

The only reason I suggested a PM was to try and find a little more about the area this is being built in. I will then redirect any other mail to the open forum. I think it is a pretty interesting subject!

Sound like you followed common sense and did not worry too much about ridiculous rules! Good for you!

Good luck.

Rectangular prism *IS* a shape. {sorry}