Different jobs require unique types of mortar, each of which may have a distinct drying time. For example, thin-set mortar used for tiles and counter tops requires 24 to 48 hours to dry while brick mortar made from Portland cement can require up to 28 days to dry.
When laying floor tiles, avoid walking on or grouting them until they are dry. Otherwise, they may shift position, which will later require a time-intensive fix.
Mortar made of Portland cement, as is used in brick walls, patios, and fireplaces, cures to 60 percent of its potential full strength within 24 hours. However, it may still contain moisture, meaning that it will not hold up under heavy use or extreme temperature change.