Why caulk matters
The caulk line where a tub meets the wall keeps water out of the wall. Once it cracks, peels or turns black, water gets behind it. Fresh caulk is one of the cheapest ways to protect a bathroom.
Grout or caulk?
Grout goes between tiles. Caulk goes where two surfaces meet, like the tub and the wall, or the counter and the backsplash. The pro uses the right one for each joint.
Let it cure
New caulk and grout need time before they get wet. The pro tells you how long to wait before the first shower, usually a day.