The floor in my shower is 20 years old and outdated. I want to modernize the shower . Do I need to remove the old shower floor tile and pan or can I just tile over the old tile. To my knowledge the old floor and pan are not leaking. The house is cement block with a cement floor.

More than likely the "pan" there is just the concrete floor and cement build up from there and not an actual pan.

I would chip out old tile and lay in new to keep it a "new" installation as opposed to trying to scab over the old floor tile.

I don't know how your shower was built from here, BUT I can tell you how it was supposed to have been built.

There should first be a pre-slope, this is made by placing deck mud slopped from taper to - 3/4" or so, slopped towards the drain. There should then be a shower pan membrane over that, the membrane is attached to the drain and continues up the walls about 6-10" and up and over the curb. This is what keeps the water contained inside the shower. Then there is another layer of deck mud approx. 1 1/4" thick or more, to which your tiles are bonded to.

If it was done correctly as above, you can NOT just remove the tiles, deck mud and membrane without removing part of the walls and curb too. That would be a silly thing to suggest anyone to do. :eek:

You can easily tile over the old shower floor if it is in good condition and the shower is otherwise in good shape as you claim. You will need to find a product called Extendo (?) Drain so you can raise the drain strainer as required. More to it than that of course.:D

Jaz