I'm looking to tile a basement floor that was dug out about 6", so there is a roughly 6" tall x 4" wide raised concrete border around the whole room, as they didn't dig out the edges. This border is mostly level but has a rounded edge, and it's painted.
I was thinking it would be a more finished look to tile over this edge with the same thing I'm using for the floor (TBD but probably slate).
How do I do this properly so that it comes out straight?
My best guess is to use a backerboard of some kind over the existing concrete border to guarantee I have a straight, level surface on which to apply the tile. I had been planning on using Ditra for the floor, in large part just because it seemed easier (and thinner) than cement board, but would I have to worry about the interface between the two? Would I attach the cement board to the concrete just with thinset, or should it be fastened somehow? Do I need to remove the paint (it's very well adhered currently, no peeling)? Or is this completely the wrong way to do this?