Grout is especially porous. This porosity makes it susceptible to the buildup of dirt and grime that eventually lead to discoloration. Being such an exceptionally porous substance, grout is the perfect incubator for mold and mildew. Every time you shower or get an area of grout wet it can take up to 72 hours for it to dry. If you shower every day, you will always have damp grout, providing an environment in which mildew loves to grow. Harsh cleaners and various bleaching agents hide the mildew at the surface but it will still be alive inside the grout. As it grows from the bottom up, eventually you will find the mildew coming back. It can seem like a never-ending cycle. Over time, these same harsh chemicals used for cleaning actually damage the surface of the grout making it more susceptible to dirt so it actually becomes dirty faster. High Country HydroShield has the solution for homeowners in Colorado!