I have a 30 year old shower base, which I think is made of fiberglass or some sort of plastic. It measures 32×47. The walls of the shower are tiled with 4×4 ceramic tiles. The base is in bad shape, it gets moldy and very dirty. I’ve tried cleaning it, but it’s had to get clean. I’ve painted it several times with epoxy paint, but it doesn’t hold up very well. There are no leaks, it’s just an eyesore. Is there any sort of liner that I could put in, or do I have to replace the entire base? If I have to replace the base, how difficult is it? Do I need to remove the entire layer of tiles that come down to the base? The drain should not be an issue, as there is an unfinished basement below the shower.