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.
Time Before Grouting. Drying time varies with ambient air temperature, humidity and moisture content of the mortar when applied. In general, mortar must set at least 24 to 48 hours before grouting. Apply mortar when the ambient air temperature is between 50 and 100 degrees Fahrenheit. Ideally, temperatures should not exceed this range for at least 72 hours after application.