This stress will be tensile during temperature decrease, or compressive. during temperature increase. If the compressive stress level exceeds the column buckling resistance of. the restrained length, then lateral buckling (or snaking) will occur.
Dry Time. In most cases, you should allow the grout to dry overnight before using that room as total dry time may take up to 24 hours. If you are thinking about sealing your grout after you have installed it, you need to wait even longer than that so that all of the moisture has had time to be released.
Let the grout dry for 10 minutes, then wash the surface of the tiles with a damp grout sponge. Move the sponge in circles over the tiles until they are clean. Rinse the sponge frequently to prevent haze. Let the grout dry for 24 hours.