Need help/advice - Cracked granite from heat - wood fired grill

[StevieD]

Hello everyone,

I am new to this forum, and came across it while googling for help on an issue I recently had. I have a house in Maine, and recently had an outdoor kitchen constructed, with an Argentine style grill. The grill is wood fired, and is constructed of stainless steel. The contractor installed the grill in a thick granite enclosure, lined with firebrick. I used the grill a few times this summer without issue - but recently had a party where we used the grill (with wood - the wood is lighted in the enclosure on the left side of the grill - as embers form, these fall through a grate and then are raked across the firebrick under the grill), and the granite enclosure on the bottom of the grill cracked (from front to back). It cracked rather loudly, and we noticed water leaking from the crack. I had noticed that the outside surfaces of the granite enclosure would get quite hot during use - but never expected that the granite couldn't take the heat. After conferring with some of the stone folks, they suggested that there wasn't enough firebrick between the heat source and the granite, or that insulating firebrick or an insulating blanket should have been used, to reduce heat to the granite. I'm hoping some of you might have some thoughts on this - should we have used insulating firebrick instead of regular refractory firebrick? would an insulating blanket under the firebrick (between firebrick and granite) have been better? Or should we just use another layer of firebrick (the bottom layer of firebrick is actually only a half height of firebrick rather than full height).

Steve

[UtahBeehiver]

Welcome to the forum, dang to bad about the granite.We get asked about the use of granite here and there, mostly on the oven landing, similar to yours. Granite cannot handle the heat of the ovens whether it be by transmission (ie through the fire brick floor into the granite) or by reflective (from the coals towards the from the coals/fire so we recommend it not be used where high heat is involved. As suggested, insulation under the fire bricks reduce the transmisson issue, You need either insulated fire bricks (IFBs) or calcium silicate board (not a blanket - too soft to support fire brick) also a perlite or vermiculite/portland mix 5 to 1 ratio could work, just depends of how my depth you have to work with.

[JRPizza]

We cracked a granite countertop from the heat of a crock pot. Sometimes it's all about thermal differential - at least it was for us. We left the slow cooker running all night during the winter where the house cooled off to the low 60's. Found the crack in the morning. No more crock pot on the drainboard.

[Alomran]

My sister's house was fully (tiled) paved with granite, she had a nasty house fire that went through the entire house on two floors constructed from concrete frame. What was shocking is that not a single piece of granite was found! All seemed to have gone/evaporated!
My personal thoughts, granite blasts at high temperatures, especially when it is in contact with cold liquid such as water. M fire place hearth was cracked when some water was dropped on it while it was hot.
Granite is not suitable for ovens and if it is hot and comes in contact with any cooler material (such as cold liquid), then at a big crack will be visible. If you have not fired the gr