First time post on this website, I hope to find some help.
I have an uncovered, outdoor fireplace that was installed around 8-9 years ago. The internal parts came in a kit with the pieces made out of a cinder block material. The exterior is sandstone rock, held in place with mortar, just like the rock on the side of my house.
We burn live oak, hickory, pecan, etc. in it during cooler weather.
My problem is that the mortar holding the fire tiles on the inside of the fire box is failing. One tile has fallen off, more are sitting in place, but are loose.
The top is pretty flat composed of mortar and rock, with a metal screen/top covering the chimney. The top has cracks in the surface plus more cracks between the surface and the rock exterior. I’m sure water is getting in and suspect that is what is causing the fire tiles to loosen. I have noticed that after a hard rain, the ashes in the fireplace are wet.
I have two issues. First, how big of a problem is this? Is the water causing the interior pieces to deteriorate? Am I looking at a problem which, if not addressed, will get worse and worse and eventually require the fireplace to be torn down and rebuilt? Or is it no big deal and I can ignore it with no ill effects?
Second, if it’s a real problem how to fix it? Can I caulk the cracks at the top? Or do I need to fix with mortar? Should I try to build up the slope the top so that rain runs off? What products should I use?
I’ve called fireplace companies and they simply sell components and won’t give advice on installation. I’ve called rock installers and they don’t know about this subject either.
Any advice along with other issues I need to consider would be greatly appreciated.