We have a fireplace that was covered with cement rocks when we moved in. We knocked off the rocks and drywalled most of the surface, but we were told we shouldn't drywall the whole thing because of fire codes. Apparently, there's supposed to be a minimum amount of space around the opening of the hearth that has to be a non-flammable material (i.e. tile). We left ourselves at least 2 feet all the way around the opening to do that, but wanted to make sure that was enough before we continue... does anyone know what is the minimum or where I can find this building code? Thanks!

Not to state the obvious but your local inspector and the NFPA codes that the local paid firemen should know or point you also in the right direction.

This is why smooth sponged parging ( stucco ) works well and passes all fire codes and it looks like finished drywall done right.