# Cracks in fire pit



## jlhaslip (Dec 31, 2009)

Are you using fire brick? or regular stone/rock?
The mortar can only do so much expansion by itself.


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## cbr549 (Oct 31, 2010)

Fire brick in the base, 4" concrete block for the sides.
it's cracking along the mortar joint though.


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## jlhaslip (Dec 31, 2009)

You are dealing with a differential co-efficient of expansion in the joint between various products an unless you can change to entirely firebrick, I'm thinking the problem won't go away.


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## Tscarborough (Mar 31, 2006)

Anything in contact with direct flame or temps higher than 500 degrees needs to be lined with firebrick laid with refractory cement. It won't be long before the CMU begin to crack and spall.


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## stadry (Jun 20, 2009)

don't pay attn to the previous posters,,, what you need to do is build MUCH smaller fires then the block won't get hot,,, did you ever hear of fireplaces built from river rock exploding ? 1 of the things i remember from boy scout days :thumbup: amazing how much information was included in that little handbook & the merit badge pamphlets,,, guess those who play little league baseball, soccer, football, etc have as much ' real life ' information to get them thru life :whistling2:

*of course listen to them* - just had to get my $.03 into the thread,,, many changes have taken place in our culture at the rate is geometric


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## Bondo (Dec 8, 2007)

> How can I repair/fix this?


Ayuh,... How about just leaving it be, 'n callin' it drainage....
It ain't like the fire is gonna drain out thru it...but the rainwater will...


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