Can I Just Put New Grout Over Old Grout?

Grout is crucial in keeping up the integrity and the look of your tiles. It does not only keep the tiles firmly fixed, but also does not allow the moisture, dirt, and bacteria to seep under the tiles. Gradually, grout may be stained, cracked or worn off and this undermines the appearance and life of your tiled places. The question many homeowners ask themselves is; can old grout be overlaid with new grout?