Hearth Opinion

[Jeff Gainey]

The home I inspected today had a fireplace with what appeared to be a marble hearth and trim about 3/4 inch thick. I remember a thread in the recent past about this not being an approved hearth material but would like another opinion. The first picture is of the underside of the hearth from the basement. I recommended a level 2 inspection as I always do since there were gaps in the firebrick and trim also. Thanx in advance for the input.
A different adventure everyday...Jeff G

[Eric Barker]

Going from memory, I think that you'd be looking for a 4 inch noncombustible base under the extension. Don't see any problem with marble extension.

[Bob Harper]

According to 2006 Ed. of NFPA 211, not must the combustible forms be stripped away underneath but a 4" clearance maintained below the HX.

Doesn't look like a 6" perimeter of marble around the opening.

Yes, need to grout the marble to the Fp proper with refractory mortar.

Nothing wrong with using marble. Cultured marble is a different story.