Q: Should I use sanded or unsanded grout for bathroom tile?
A: The sand in sanded grout makes it stronger than the unsanded variety so it resists shrinkage and cracking better. Sanded grout should be used in all joints larger than 1/8 inch. For most projects, sanded grout is the best choice. However, for more delicate tiles such as marble or polished stone, use only unsanded grout to avoid scratching the surface.