Someone painted the shower floor/basin with some type of rubberized waterproofing sealer. We have peeled off most of it but it is stuck in all the grout linesa in the tiles under neath it . We've tried most every cleanser and even a steam cleaner but it won't budge. Does anyone know what I can use to get this stuff off? THANK YOU FOR YOUR HELP, Betsy

Heat?

Hey Betsy:

Only thing I come up with is a tile GROUT saw.

It is a little saw that fits in the grout line and saws out old material (see pics. Below).

After using this tool you would want to clean real well and then purchase grout and grout float and re-grout the shower floor.

Hope that helps you out... Mark