I have another post in this forum that has nothing to do with this one in case you were wondering. Anyway, in my basement I have a shower stall with a 36" square pan and some form of cultured marble walls. The walls are in great shape which leads me to my problem. When the shower pan was installed, concrete was not put underneath to fill in any unevenness between the slab and the pan and over time the floor of the pan has started cracking. Currently there are two hairline cracks roughly 4 - 5 inches in length radiating out from the drain. Normally the shower isn't used but I am redoing our master shower and we are using it regularly. I can't think of any easy way to fix this. Since the shower is normally only used a couple times a year, I would be willing to put up with a pseudo-fix until we dislike the shower walls enough to replace everything. The only other option I can think of is removing the pan chunk by chunk and then rebuilding one out of tile. Any other thoughts? Thanks.