How to clean a headstone safely
The conservation-approved method used by cemetery preservationists — and the common mistakes that permanently damage stone.
Cleaning a family headstone is one of the most meaningful ways to care for someone's memory. Done gently, it can return a weathered stone to legibility. Done wrong — with bleach, a pressure washer, or a wire brush — it can erase an inscription forever. This guide follows the methods recommended by the National Park Service and the National Cemetery Administration for government headstones.
First: know when not to clean
Never clean a stone that is cracked, flaking, sugaring (surface turning to powder), or rocking on its base. Cleaning fragile stone accelerates the damage. Older marble and sandstone markers — common before the 1920s — deserve extra caution. If in doubt, photograph the stone and consult a professional first.
What you need
- Several gallons of clean water (many cemetery sections have no spigot — bring your own)
- Soft natural-bristle or nylon brushes (a large one for faces, a toothbrush for lettering)
- Plastic or wooden scrapers for thick moss (never metal)
- D/2 Biological Solution — the biocide used at Arlington National Cemetery — for lichen and algae
The method
- Soak the stone. Wet it thoroughly with plain water before touching it with a brush. Dry brushing grinds grit into the surface like sandpaper.
- Scrub gently, keep it wet. Work in light circular motions with the soft brush, rinsing constantly. Start conservative — you can always do another pass.
- Lift heavy growth with a plastic scraper. Hold it at a shallow angle; if growth doesn't release, leave it for the D/2 rather than forcing it.
- Apply D/2 to biological staining. Spray on, wait 10–15 minutes, agitate lightly, rinse. D/2 keeps working with rain over the following weeks — stones often look dramatically better a month later.
- Rinse bottom to top. Rinsing upward prevents dirty streaks from setting on the lower face.
Expect a well-done cleaning to last three to five years, longer for granite in sunny plots.
Granite vs. marble vs. bronze
Granite (most stones after ~1930) is durable and tolerates the full method above. Marble and limestone are soft and dissolve slightly with every cleaning — clean these less often, more gently, and never with anything acidic. Bronze markers need a different process entirely: mild non-ionic soap, then a paste wax; never abrasives or brass polish.