How does one clean a cemetery headstone?

Just like people do, a healthy cemetery ages; it will sometimes show its age in the form of moldy, old headstones. Cleaning the headstones is a necessary component of cemetery maintenance -- often performed by doting family members -- albeit very arduous and tedious. Save Texas Cemeteries would like to inform you of any and all effective and sound strategies for cleaning cemetery headstones, so here is the headstone cleaning method developed from data supplied by John R. Dennis of the Dallas Museum of Art Conservation Lab.

CLEANING STONE

Check the stone's condition before cleaning. No stone should be cleaned if its condition is questionable, such as:

• a stone with a friable or "sugary" surface;
• a grainy surface that readily falls away;
• any other condition that indicates that the stone is delicate, brittle, or otherwise vulnerable.

All surfaces of the stone should be checked. If there is any question as to the stone's condition, do not attempt to clean it, as the surface could be irreparably damaged in the process.

THE CLEANING PROCESS

1. Mix a solution of one heaping tablespoon of ORVUS® to one gallon of clean water. ORVUS® is a detergent that comes in either liquid or paste form. It is commonly used in association with horse and sheep husbandry, and is available from feed stores.
2. Pre-wet the stone thoroughly with clear water, to make sure the detergent solution will not be absorbed directly into the dry stone.
3. Thoroughly wash the pre-wetted stone with natural, bristled, wooden handled brushes of various sizes. The use of plastic handles is not recommended, as colors from the handles may leave material on the stone that will be very difficult to remove. Be thorough. Wash all surfaces, Rinse thoroughly, with lots of clean water.

REMEMBER!

• Do pre-wet the stone with clear water prior to cleaning, and keep the stone wet during the entire washing process.
• Do not allow the detergent solutions to dry on the stone while cleaning.
• Never use abrasives, high-pressure washes, acids or bases, solvents, household cleaners, wire brushes, or blasting equipment to clean stone!

CLEANING MARBLE AND LIMESTONE

When cleaning marble or limestone, one tablespoon of household ammonia can be added to the above mixture; this will help remove some greases and oils. Do not use ammonia on or near any bronze or other metal elements.

LICHENS AND ALGAE

Lichens and algae can be removed by first thoroughly soaking the stone and then using a wooden scrapper to gently remove the biological growth. This process may need to be repeated several times to remove the material.

STAINS

Some stains in porous stones cannot be removed. Do not expect the stones to appear new after cleaning.

FREQUENCY OF CLEANINGS

Do not clean marble, limestone, or sandstone more than once every 18 months. These types of stone may occasionally be rinsed with clean water to remove bird droppings and other accretions. Granite can be cleaned as needed.

KEEP A RECORD OF THE CLEANING

Simple treatment records should be kept with the date of cleaning, materials used, and change in condition since last cleaning (such as missing parts, graffiti, and any other damage). These records should be kept at a central location where the condition of the stone can be monitored over time.