what can grout be used for
Often, installers use grout in place of caulk for these reasons: 1  The caulk may not exactly match the grout color.  Even when the caulk exactly matches the grout color when installed, it may not match six months later (caulk will age differently from the grout).
However, when grout is used in place of caulk, the grout can cause structural and aesthetic problems. 1  The grout will crack allowing moisture to penetrate. 2  Where the grout is sufficiently strong, movement in the walls, floor, or countertop can damage the tile.  Grout cannot hide corner cuts as well as caulk.