[NickCat11]

Hello All,

I recently completed a masonry fireplace here in NJ. The fireplace was allowed to sit around 45 days without a fire. It was built out of cinder block and veneered with stone. After the first couple fires there is cracks developing in the mortar, the bluestone hearth, and the bluestone rim above. One outer edge firebrick is cracked as well. Any insight on what could be happening and how to fix it? The fireplace is on a strong footing. I compacted 6" of traprock and then poured a 18" deep footing with rebar. Footing is over-sized 12" on each side. Looking forward to your help, thanks. Pics below...

 

[Windows on Wash]

First few fires probably forcibly dried it out to the point where it shrunk a bit.

I have seen some guys burn a few fires in them prior to putting the finished faces on it.