Are all fire bricks the same

  • Active since 1995, Hearth.com is THE place on the internet for free information and advice about wood stoves, pellet stoves and other energy saving equipment.

    We strive to provide opinions, articles, discussions and history related to Hearth Products and in a more general sense, energy issues.

    We promote the EFFICIENT, RESPONSIBLE, CLEAN and SAFE use of all fuels, whether renewable or fossil.
Status
Not open for further replies.

Burd

Feeling the Heat
Feb 29, 2008
438
Bell bell Pa.
This summer I'm looking to replace all the fire brick in side my insert. It seems that all the bricks are starting to crack and crumble.
So my question is.
1. Are there bricks out there that will retain the heat longer then others.
2. My baffles are in good shape,but is it worth replacing them as well.

I dont now much about fire bricks except that theres different sizes.

Thanks to all, for all your help. If it wasnt for you this site would suck. Keep up the good work.
 
What kind of insert are you running?

Adding it to your signature can be done by clicking on "your control panel" at the top of the page.

pen
 
Take a firebrick out & measure it. If it's
9x4.5x1.25", it's called a "Split" firebrick...That's
what most manufacturers put into their woodstoves
& inserts. If you buy from a hearth shop,
they'll cost you about $3 each. If you by from a
masonry supply outfit, about $1.50 each. There
ARE different types, but standard split bricks are fine.
They are primarily used to reflect the heat back towards
the middle of the fire box, making the stove burn hotter,
altho they DO insulate the sides & bottom of the fire box.
If you have to cut a split brick, a tile-cutting wetsaw is the
ideal tool for the job...
 
The bricks are 9x5x1.25 Im not going to have any problems reinstalling them as I have a garage full of tools.
I really thought that the brick would hold the heat in longer like a clay furnace. Has any one come across bricks that are better then others.
 
Like a metal wood stove is not the best material
in which to burn wood most efficiently, fire brick
is not the best material to line a firebox.

Metal wood stoves are compromises at best.

As for the fire bricks, they can withstand very
high temperatures. Much higher than what is
required in a metal stove firebox. They are
made for industrial applications (not for us wood
burners) to take HIGH temperatures and KEPT
there. Our little metal stoves don't generate
the heat that makes them fail (CRACK). Our stoves
heat then cool, heat then cool. This THERMAL CYCLING
or THERMAL SHOCK is what causes the failure of the
fire brick (along with trauma from tossing wood chunks).

So, an expensive super heavy duty industrial firebrick
is not necessarily what you are looking for. Any brick
will crack the way we use them. Red brick has more
impurities, like iron, that make them more brittle than
gray clay fire brick - not the best for our firebox.

Therefore, the best we can do is realize we are dealing
with compromise and replace a cracked fire brick when
required and go about our day.

Aye,
Marty
 
The quick and easy answer is "Yes", there are different types of firebrick. For instance, Quadrafire uses a different brick than Englander. The noticeable difference is the density of the brick. One is quite a bit lighter than the other but is said to have better insulating properties. Again using Quad as an example, they do not recommend the use of the heavier density brick. They want the owner to stick with the other stuff. YMMV
 
  • Like
Reactions: Starbrightsteve
Jags Thanks this is exectly what I was tring to get at. My warrenty is well over and Im looking to make this stove more efficent. If you were going to replace the bricks witch one do you go with? IM looking to hold the heat longer. ( like putting a after market air cleaner in the truck to get better proformance )
Has any one noticed any differents by doing this
 
I would personally stick with the same style as the mfg. put in the unit. I don't mean that you have to buy from the mfg, but the brick style chosen by the mfg was for a reason. Whether it was for - heat reflection, insulating value, what have you - I ain't gonna try and figure out WHY the engineers did what they did.
 
I asked this question a while back and no one seems to have tried a different one in their stove, my old stove had the heavier ones and the new stove has the light ones, I guess I could call PE and get their opinion on it.
 
oldspark said:
I guess I could call PE and get their opinion on it.

I gar-own-double-damn-t that they will suggest OEM.
 
Jags said:
I would personally stick with the same style as the mfg. put in the unit. I don't mean that you have to buy from the mfg, but the brick style chosen by the mfg was for a reason. Whether it was for - heat reflection, insulating value, what have you - I ain't gonna try and figure out WHY the engineers did what they did.

Yup. Jags is right for once. Super duty bricks are more dense and will hold more heat, but they also conduct heat to the shell better. The bricks they use are formulated to insulate to a given extent, I assume to prevent overfires etc.
 
The denser brick is baked alumina and silica, the lighter brick is made from pumice. Pumice brick is better insulator and is used to keep the firebox hotter. The downside is that it is more expensive and less common.
 
Adios Pantalones said:
Yup. Jags is right for once.

I never tire of hearing that - hey, wait a minute...ONCE!
 
Wow that's cool I got some great info. I'm sure that napolean didn't put in pumice
if its more expensive. Is the pumice brick brittle our
do they hold up better then the other
 
I experimented with my P.E. super 27; I changed out the standard stock "pumice" bricks and put in the heavier clay brick sides and back only. I thought that the heavier mass would hold the heat longer in the cooling stage, and radiate better. What I discovered was: the pumice bricks are better, the fire is hotter, just performs better.

I think a lot of the stove's heat comes off the top plate. I thought because of the insulating nature of the pumice brick, a lot of the produced heat will be reflected away from radiating into the firebox.

I filled in the gaps-about 1/2".above the side wall and back wall with strips of an extra pumice brick. Also I modded the air lever stop to allow me to reduce the airflow more.
 
Burd said:
Wow that's cool I got some great info. I'm sure that napolean didn't put in pumice
if its more expensive. Is the pumice brick brittle our
do they hold up better then the other

I believe the pumice to be a bit more fragile.
 
BeGreen said:
The denser brick is baked alumina and silica, the lighter brick is made from pumice. Pumice brick is better insulator and is used to keep the firebox hotter. The downside is that it is more expensive and less common.

I am surprised to hear that. Most pumice is feldspathic and therefore not refractory enough for high temps. It may be more than good enough for the temps in a woodstove, however.

My understanding is that high temp insulating refractory bricks (IFB's) are normally made from some sort of clay with a combustible (rice hull ash or sawdust) mixed in that burns out during firing to create air spaces. I have actually made small components by this process. I have bought G26 IFB's- good to 2600F, which would definitely be beyond the limits of a feldspathic material.
 
Wow now i'm not sure on what type of brick I have in there. How do you find out
 
Ubookz said:
I experimented with my P.E. super 27; I changed out the standard stock "pumice" bricks and put in the heavier clay brick sides and back only. I thought that the heavier mass would hold the heat longer in the cooling stage, and radiate better. What I discovered was: the pumice bricks are better, the fire is hotter, just performs better.

I think a lot of the stove's heat comes off the top plate. I thought because of the insulating nature of the pumice brick, a lot of the produced heat will be reflected away from radiating into the firebox.

I filled in the gaps-about 1/2".above the side wall and back wall with strips of an extra pumice brick. Also I modded the air lever stop to allow me to reduce the airflow more.
Cool someone has tried it (figured it might not be as good), do you think filling in the gaps above the side bricks helped any?
 
Burd said:
Wow now i'm not sure on what type of brick I have in there. How do you find out

Weight is a dead give away. A firebrick split weighs about 4 lbs? The pumice brick is maybe half that weight? Pumice bricks are also a bit less smooth.
 
im thinking the blazekings come with pumace because the texture of the firebrick is allot rougher then the englanders smooth brick, or the firebrick i have purchased locally.
 
We just had a Napoleon 1101 delivered last week and I thought it was strange that it had three types of firebrick in it, what I consider the typical firebrick that you see everywhere was the main type. Some of the cut bricks were the pumice type (much lighter and rougher).
In the back top, two of the bricks were very dense and smooth. I don't have a lot of experience with firebrick but I had never seen any like that before.
 
Jeffoc
Now that you posted. Ill bet that my 1402 has the same thing going on. At the front of the box theres two peacies that are cut and helps lock the side walls together and if im thinking right there pumice the floor was fire brick.Top back wall doesnt even go all the way up to the baffle but the top brick is pumice
Will the manual have witch type of brick goes were.

Man this project is going to suck and I havn't even gotten started.
 
Status
Not open for further replies.