Although it is not fireproof, I have my studio floor covered with
carpeting for several reasons. First of all, it is comfortable
underfoot, and equally important, when I drop something on it I do
not have to worry about breakage---and believe me, I drop plenty of
stones, which usually stay where they fall and are easy to retrieve.
It is even carpeted in the soldering area. Ideally, it should be
fireproof in that area, but in 20 years (yes, same old carpet), I
have never had anything hot fall on it. I do keep a fire extinguisher
and a bucket of water close on hand, but have never had to use them.
It is another story in the separate studio where I fire my enamels,
burn out my waxes, do casting, and work with acids for etching
etc..--in short all the dangerous messy stuff. There, the floor is
concrete, except in areas which are not in danger of flammable items.
i would suggest since you will be starting from scratch, that You
use a hard fireproof surface in areas which need protection,( which
would rule out wood flooring, which might burn), and put some
carpeting where you do your stone setting etc..