Gravestones are exposed to all the elements, which often results in plant growth, including algae and moss, overtaking the stone. This plant life is not only unattractive, but also harmful. Older gravestones are especially vulnerable, as plant life can cause breakage and chipping. Marble gravestones can be cleaned using a few simple steps and some ordinary supplies.
Put on protective gloves and goggles.
Spray the marble gravestone with clean water from a pump sprayer.
Cover the gravestone with a non-ionic detergent. Allow the detergent to set for about 15 minutes.
Scrub the gravestone with a natural-bristle brush, moving from the bottom to the top of the stone.
Repeat the process of spraying and scrubbing the gravestone until all moss, algae and other grime is removed from the marble. The process may as many as five applications or more.
Rinse off all detergent and plant growth from the gravestone with the pump sprayer before the detergent has a chance to dry to avoid smudges and streaking.
Wipe down the gravestone with soft, clean rags in a circular motion.
This method can also be used on limestone and sandstone gravestones.
Do not clean a marble gravestone with a wire brush, pressure washer or acidic cleaners, which are harmful when used on marble. Do not clean gravestones without permission from the proper authorities. Do not clean gravestones that are flaking, chipping or otherwise falling apart.