granite hearth cracked

finchsaundersDecember 20, 2009

What should we do next? Our 1 1/4" thick absolute black granite hearth has cracked down the middle from the heat of our fireplace. We don't know what to do. The hearth was installed on top of our wood floor, and the first time we had a fire (with normal-sized firewood)it cracked. The slab was replaced only to have the new one crack with the next fire! The only "different" thing about this hearth is that it sticks into the fireplace about 1 1/2" across the width of the fireplace. The part of the hearth that sticks into the fireplace entrance is 4 1/2" away from the andirons. I assume that the hearth needs to be farther away from the heat, but haven't heard of others having this problem. Advice???

Thank you for reporting this comment. Undo

Properly installed granite should not crack from heat (unless it's not thick enough for this purpose). It is possible that both slabs had hidden internal cracks which were revealed only when the hearth heated up. Another possibility is that the two fires were excessively hot. Starting with a series of smaller fires to acclimate the slab may be necessary to prevent cracking. One more possibility is that the mortar used to set the granite was not fully cured and flexed in such a way that it cracked the stone.

    Bookmark   December 21, 2009 at 5:33AM
Sign Up to comment
More Discussions
Gas Fire Place
I have a direct vent gas fireplace with a standing...
direct vent gas fireplace
Hello, I just bought a house and there is a Monessen...
Can woodstove clog a chimney in a month??
We had a Quadrafire 5100 woodburning stove insert installed...
Hot wall
Hi , I've posted this here before but will try again...
best way to clean a brick hearth?
i have tried washing the brick, but it still looks...
People viewed this after searching for:
© 2015 Houzz Inc. Houzz® The new way to design your home™