Save Historic Gravestones with a Good Cleaning

Cemeteries should be timeless venues where descendants can visit the resting places of their ancestors. Lichens, black mold and airborne pollutants wage a silent assault on the grave monuments that pay tribute to the dead. But with a good, careful cleaning, these stone remembrances can be saved from eventual destruction.

Before and after cleaning a badly contaminated grave monument.

Today’s cemetery headstones are better resistant to the ravages of time than markers created more than a century ago. Older monuments were often made of porous materials that are susceptible to weather wear and infiltration by biologic growths such as mold, moss and lichens. Like the patina on a copper statue, these growths can look like they add character to historic cemeteries. But they are actually very destructive and should be treated and removed.

The good news is with a little effort and the right materials, just about any grave marker can get a new lease on life. We recently treated a number of monuments at a cemetery in Brown County, Wisconsin. The lettering on one monument was filled with lichens, rendering the text almost unreadable. Another was badly blackened by mold. Both stones are more than 100 years old.

After less than an hour of cleaning effort, the lettering on this monument became clear and readable.

We treated them with D/2, a safe biodegradable cleaning agent available from many cemetery supply outlets. It is important not to use harsh cleaners on monuments, since they can actually damage and weaken the stone. D/2 is the only cleaner approved by the National Park Service for sites such as Arlington National Cemetery.

Other guidelines we follow when cleaning cemetery monuments:

• Only work on monuments that are stable and free from major structural damage. You don’t want to topple a stone or cause any damage.
• Have plenty of water available to pre-soak the stone and then to rinse away the cleaner and contaminants. Some cemeteries have water stations where you can hook up a garden hose. Otherwise, it is good to bring 5-10 gallons of water and spray bottles or a pump sprayer.
• After spraying the cleaner and letting it settle for 10-15 minutes, use soft-bristle brushes (natural or synthetic) to gently scrub away growths and stains. Never use wire brushes or stainless steel scrub pads.
• Use plastic or wood scrapers to remove growths from the surfaces and from inside the lettering. Metal instruments can damage the stone.
• Do not use power tools such as sanders, pressure washers, drills, etc. Only use your hand power with the types of brushes and tools mentioned above.
• Work from the base of the monument upward to the top. This is especially important on tall monuments. It avoids risk of leaving marks as the cleaner drips downward.
• Don’t worry if the stone turns colors during chemical treatment. The D/2 solution often turns the stone orange. It can take several months to see the full effects of cleaning and treatment. The orange will fade away, leaving the original color of the stone.
• Make sure to bring a camera to document the before, during and after.

For more information about cleaning cemetery monuments, contact Joe Hanneman at Treasured Lives (joe@treasuredlives.us).

After cleaning, this monument still showed an orange hue, which means the anti-biologic chemicals are safely working. After 3-4 weeks, the monument will look white again.