Step 1

sandpaper could be the answer to dirty grout

Try Sandpaper

Many stains are on the surface of the grout and can be removed with sandpaper. Just fold the sandpaper into a crease, and work it back and forth along the grout line. If sandpaper doesn't work, you may have better results by applying a pencil eraser.

Step 2

Use Solution to Remove the Grout

If sandpaper or an eraser fails to remove the stains and dirt, try an over-the-counter grout cleaner -- or create a similar solution from household bleach and water. Squirt or pour the solution onto the grout, and scrub with a toothbrush. Make sure the area is well ventilated, and wear rubber or latex gloves when working with bleach.

Step 3

Remove and Replace the Grout

If bleach doesn't do the job, you may need to remove and replace the grout. Use a grout-removal tool or a rotary tool with a carbide tip (Image 1). After you install new grout, seal it with a grout sealer (Image 2) to reduce the likelihood of future stains setting in. Reapply sealer once every two years.