Similar to the tiles themselves, grouting should be left to sit for at least 24 hours before you start walking on the tile you’ve installed, for example, on your bathroom floor. If you don’t wait long enough and walk on the tiles before the grout has properly dried, you could make the tiles shift and become uneven — leaving a devastating aesthetic effect that would be very costly and time-consuming to repair. Again, always follow the instructions on the products you’re buying. You won’t regret doing your research and heeding directions when it comes to installing tiles.