A handyman suggested to me that I might need to periodically apply water-sealant to the tile and grout on the tile wall of my bathtub. Is he correct?
If so, what's a good sealant to use, how is it best applied, and how often should I re-apply it? (It's probably been 15 years since the previous owner refinished this bathroom and put in a tile wall, so probably been 15 years since any sealing was done.)