Tile adhesive dries in a way that is very similar to concrete. The substance starts out as a powder and then, when mixed with water, it becomes a substance with a thick consistency. Under normal circumstances, you will need to let it dry for approximately 24 hours after installation before you can walk on the tile. There is another type of tile adhesive that is designed to dry faster than that, usually in about 4 to 6 hours. Do some preliminary research online to see which kind will work best for your DIY task. You can also go to your local hardware store whenever you're ready to buy supplies for the task and ask employees which adhesive they would advise based on what you're doing.