It is grout. It should remain grout for drainage reasons. Dig out the old,
deteriorated grout and re-grout. The grout is porous and allows the
moisture that goes through to weep down the underlayment and out the bottom
over the lip of the shower pan.
Many people just caulk but that traps the moisture and you will soon have an
nice black line of mildew around the bottom the needs to be re-done every
few months.

Inspector Dana
"toller" wrote in message
...
My shower has tile walls and a fiberglass bottom. As far as I know (I
have
lived here 12 years) it has never been recaulked, and it is about time.

I started to remove the old caulk and found it is hard and grainy. Could
it
be grout rather than caulk? If it is grout, can I clean it up and put
caulk
over it? Or do I have to dig it out and regrout?
Or is it not grout?

The rest of the walls are in pretty good condition, it is only where the
base and the wall meet that are deteriorated.

Thanks.
Thanks.