The answer to 'why is my grout grimy' is that grout can become discolored and grimy over time due to a few common causes. Grout is porous and can easily trap dirt, grime, and moisture, leading to discoloration and a grimy appearance. This is especially common in high-traffic areas like floors and showers where grout is exposed to more use and spills.
Some of the most common causes of grimy grout include lack of regular cleaning, soap scum buildup, mold and mildew growth, and general wear and tear. Grout that isn't properly sealed can also become discolored more easily. In some cases, the grout may have been improperly installed or low-quality grout was used, leading to faster deterioration.