I really like the look of tile running up the sides of bathtubs when you have the standard bathtub shower combo. How do I know if it’s appropriate to tile the front of my tub? Do I need to have a special type? If not, how do I prevent water from seeping in between the tub and the tile?
I would build a more suitable surface to tile in from the tub. Most tub/shower combo units are made from fiberglass or another similar material which is simply too flexible to properly support tile. You could build a structure in front using kerdiboards or cement board and waterproof and tile over that but I would not recommend attempting to tile directly to the tub surface.
The answer is very simply - you need a drop in tub.
A frame is built and covered with cement (float or wonder boards) on top of which tile can be installed.
Then, a drop in tub gets “dropped in” and properly installed.
Best,
Roy