I’m fixing up a Victorian house from 1900. We used a 42″x60″ TileRedi shower pan in the bathroom. I just finished tiling the shower, from the floor to the walls. When I fill the pan with water, it doesn’t drain right. There’s a 3/16-inch-deep puddle (see the reflection in the photograph). I think there are probably two problems: 1) The base wasn’t set up perfectly straight. I put a level on the curb to prove this. (My framers set the pan, not me.) 2) I think that under the tile in the pan, the thinset is just a little bit thicker near the drain. If I put a 2-foot level on the pan from the trough to the middle, it shows “level,” not sloping down to the drain as it should. But the water doesn’t pool higher up in the pan, so that’s how I came to my conclusion. (I put down the tile, so if this part is true, it’s my fault.) Here’s the question: I want to fix this by just tiling over the old tile. I’ve read a few things that say this is fine (incl in FHB). What they don’t say is how to change the slope of the base in the right way. Should this be something I do with thinset? A little brick? Also, is there a certain way I can make sure I get the slope right this time? I only have about 1-1/2″ to work with here, or my “curbed” shower will start to become “curb less” at the shallow end. The photo shows about 48″ of the pan. Notice how the window can be seen in the photo. The puddle goes from where the water drains out of the trough to about where the coloured piece of plastic is sitting.