I used Mapei Grout Maximizer to seal the grout. How long does it need to dry before we can use the shower?
Manufacturer directions should state minimum time after sealing for use. It is important to “test” sealer by sprinkling a few drops of water on the sealed grout to make sure it is repelling water. If the water is spreading out and being absorbed, you need to apply another coat of sealer and allow to dry at least two hours.