Cleaning a headstone sounds simple, but the wrong method can permanently damage it. Granite tolerates more than marble, older stones tolerate almost nothing, and aggressive cleaning can void a cemetery's rules as well as strip the stone's surface. This guide explains what is safe, what to bring, and when to leave the stone alone.
Before you start: ask permission
Most cemeteries have rules about cleaning, and some require staff to do any work on graves. Check with the cemetery office before cleaning a stone that is not your family's, and never clean a historic marker without the owner's or caretaker's consent. On public land or in abandoned cemeteries, contact the county or the local historical society first.
What to bring
Everything you need is cheap and gentle:
- Water. Lots of it. Pump sprayer or several gallon jugs; the stone should never dry out while you work.
- Soft brushes. A nylon brush with medium-soft bristles for granite, a very soft horsehair or baby brush for marble and older stone. No wire brushes, ever.
- Plastic scrapers. For lichen and moss that do not release with water alone.
- Clean cloths or sponges. White, so you can see what is coming off.
- Ample time. Work in the morning, bring more water than you think you need, and plan on at least fifteen minutes for a modest stone.
Do not bring household cleaners, bleach, vinegar, pressure washers, or metal tools. Each of them can etch the surface, kill grass around the grave, or drive moisture deeper into the stone.
Step 1: Read the stone
Look closely before touching anything. Cracks, flaking layers, a stone leaning at an angle, or lettering that is already lifting all mean hands off. Water and brushing can turn a fragile stone into a broken one. If the stone moves when you press it gently, report it to the cemetery instead of cleaning it.
Check what the stone is made of, because that decides everything that follows:
- Granite (speckled, hard, common after the 1940s) is the most forgiving stone.
- Marble (smooth, often white or gray, common from 1850 to 1920) is much softer and acids damage it instantly.
- Sandstone and limestone are porous and fragile; treat them like marble, only gentler.
- Slate (dark, thin, common in New England before 1850) holds carving well but can split along layers.
Step 2: Soak, do not scrub dry
Saturate the entire stone with water and keep it wet. Dry brushing grinds dirt into the surface like sandpaper. Spray or sponge water over the stone repeatedly while you work; a pump sprayer set to mist keeps both hands free.
Step 3: Clean from the bottom up
Work in small sections, starting at the base. Dirt runs downward, so cleaning from the top streaks grime over the parts you already finished. Use the soft brush with short, gentle strokes, keeping the surface wet the whole time.
For raised lettering, brush along the grooves rather than across them. For polished granite, light pressure is enough. For marble and old stone, think of it as sweeping dust, not scrubbing.
Rinse constantly. If the water running off the stone is still dark, keep going; if it runs clear, you are done.
Step 4: Deal with lichen and moss carefully
Lichen grips stone with tiny roots, so pulling it off dry takes the surface with it. Instead:
- Soak the growth thoroughly and let it soften for ten to fifteen minutes, re-wetting as needed.
- Use a plastic scraper held almost flat to lift the loosened lichen at its edge.
- Brush gently and rinse.
Biological growth on very old stones is sometimes considered part of their historic character. In a registered historic cemetery, ask before removing it.
Step 5: Rinse and walk away
Finish with a full rinse from top to bottom and let the stone air dry. Do not seal it: commercial sealers trap moisture inside the stone, where freeze-thaw cycles can split it. Do not wax or polish.
What never to use
- Bleach and chlorine cleaners leave salts in the stone that erupt as white crusts and can keep damaging it for years.
- Vinegar and acidic cleaners dissolve marble and limestone on contact.
- Pressure washers drive water into pores and blast away flaking surfaces.
- Wire brushes and metal scrapers leave rust stains and scratch soft stone.
- Household detergents and cleaners contain surfactants and salts that penetrate the stone and can feed future growth.
When to call a professional
Some jobs are beyond safe DIY cleaning:
- Fragile, cracked, or flaking stones, especially pre-1900 marble and sandstone
- Heavily stained marble where a conservator may use specialty poultices
- Stones that need resetting in their base, which should never be DIY
- Any monument too large to treat without ladders or lifting
A monuments conservator trained in historic masonry is expensive but costs less than a stone destroyed by bleach. For veterans' markers, see whether the VA or the cemetery's care fund covers maintenance before paying anyone.
How often to clean
A gentle clean every year or two is plenty for most stones. Over-cleaning, especially with anything beyond water and a soft brush, shortens a stone's life. A light annual rinse and brush keeps growth from taking hold without stressing the stone.