The answer to 'grout dusty' is that dusty grout is a common issue caused by a buildup of dirt, debris, and grime in the porous grout lines. This can happen over time as the grout becomes worn and absorbs more dirt and moisture. Symptoms include a hazy, discolored appearance and a gritty feel to the grout.
There are several solutions to address dusty grout, ranging from DIY cleaning methods to professional deep cleaning. For light to moderate dust, you can try scrubbing the grout with a stiff-bristle brush and a grout cleaner. For tougher buildup, you may need to use a grout haze remover or an acidic cleaner. However, for extensive damage or if you're unsure of the best approach, it's best to call in a professional cleaning service to properly clean and reseal the grout.