Installing a Tiled Shower

Q: When installing a tiled shower, should I use grout or caulk at the joint where the tile walls meet the tub?

A: For tiled showers, grout goes in the joints between tiles that are on the same plain (walls, horizontal shelves, etc.). However, waterproof caulk/sealant should be used in any expansion joints, such as the 90-degree angles where the tub meets the tile, because it is more flexible and helps to absorb movement. Make sure the caulk/sealant you use is formulated to resist mold and mildew.