Max temp for Masonry chimney?

[SundanceT]

Hello!

I have a wood burning insert seated in a stone hearth. With these cold weather temps I have been burning hotter and longer than before. I put a simple digital room thermometer on one of my hearth stones above the insert and it registered around 98F. The stones are warm if not hot to the touch.

How hot can they (safely) get? It would make sense that they would retain and radiate some heat as part of the design. But how much? Will the rocks pop?

What kind of thermometer should I get, where do I put it, and what are my goal temps?

Thank you!

 

[Nick Mystic]

As you can see in my avatar I have a Jotul F 600 woodstove sitting in front of my masonry fireplace/chimney. When it is burning the bricks directly above the fireplace opening will register about 225F and I don't have any problems. After all, a fireplace is built to contain a fire, so they expect the bricks to get pretty hot. I suspect the same holds for a stone hearth/fireplace. I take my readings with an infrared laser thermometer.

 

[rwhite]

I certainly wouldn't worry about 98. Rocks get hotter than that just sitting outside.

 

[SundanceT]

Thank you!