The answer to 'why is my grout filthy' is that grout can become discolored and dirty over time due to a variety of factors. Grout, which is the cement-based material used to fill the spaces between tiles, is porous and can easily absorb dirt, grime, and stains from everyday use. This can lead to a dingy, unsightly appearance in your tile floors or walls.
Some common causes of dirty grout include spills, tracked-in dirt, mold and mildew growth, and improper cleaning techniques. Over time, the grout can become discolored and stained, making the entire tile area look old and unkempt. Proper maintenance and regular cleaning are key to keeping your grout looking fresh and clean.