Cleaning and caring for a headstone: granite, marble, bronze

A gentle hand beats harsh chemicals

Stone looks tough, but its surface is sensitive. Once the polished layer that gives granite its depth and shine is scratched, it cannot be restored without specialist treatment. Marble reacts to even a brief touch of acid. So when cleaning, the most useful tool you have is patience: water, a few drops of neutral soap, a soft sponge and time for the dirt to soften. Many stains will not come off in one visit, but after several careful cleans they gradually fade. That is far better than one aggressive attempt that leaves a mark for good.

Before you start: identify the material

Before you put anything on the stone, make sure you know what the memorial is made of. A dark, shiny stone with a visible grain is, as a rule, granite. White or pale stone with a slightly warm-looking surface and veining is most often marble. The lettering may be carved and painted, gilded, or made of separately fixed metal letters. If in doubt, treat the stone as though it were the most delicate material of all. Test any new product first on a small, hidden spot, for example the back of the plinth, and move on to the visible surface only once you have seen the result.

Washing polished granite

Granite is the most forgiving material. First soak the surface generously with clean water to rinse off dust and grit, so they do not scratch the stone when you start wiping. Then dissolve a few drops of colourless, unscented neutral soap in a bucket of water and wipe the memorial with a soft cloth or sponge, working from top to bottom. Rinse away every trace of soap, and finish by drying the surface with a microfibre cloth. That last step matters most on black stone: water left to dry by itself leaves white drip marks, and the memorial looks untidy.

Marble: porous and afraid of acid

Marble is made largely of calcite, which reacts with acid. That rules out vinegar, lemon juice, rust removers, all-purpose bathroom and kitchen cleaners, bleach and anything containing chlorine. Scouring powder and a rough sponge scratch the surface and push dirt even deeper into the pores. Clean marble with plain water and a soft natural-bristle brush, adding the smallest amount of neutral soap only if you need it. You can read more about the particular qualities of white stone on the marble headstone page.

Pressure washers and old stone

A pressure washer promises quick results, but on an older memorial it often does damage. The powerful jet strips away the weathered top layer of stone, washes the grout out of the joints between the tiles, blasts paint out of the lettering and can hit the photo plaque. Do not use one on marble or on stone that has stood for many years. On new, sound granite it is relatively safe, but only at low pressure, held well back from the surface, and never pointed at the lettering or the portrait.

Moss and lichen

In a shady, damp spot a memorial picks up a green film and moss, and sometimes lichen too, which shows up as crusty grey or yellow patches. Moss is easy to remove: wet it, wait a few minutes, lift it off with a wooden or plastic scraper and then go over the area with a soft brush. Lichen grows tightly onto the stone, and tearing it off by force damages the surface. Loosen it gradually, over several visits. Never use a wire brush or a knife. Less shade, trimming overhanging branches and clearing leaves regularly all slow down its return.

Bird droppings

On a memorial under a tree, bird droppings are a frequent problem, and the sooner you remove them the better. They contain acidic substances that slowly dull the surface of marble, and a dried-on patch is harder to shift even from granite. Do not scrape dry droppings off by force: soften them with water first, lay a damp cloth over them for a few minutes, and then lift them off gently with a soft sponge. Finish by rinsing the area with clean water. If a stain has left a dull patch on marble, only professional surface treatment can put it right.

Candle wax

Wax drips are the most common mark of all, especially after the days of remembrance. Do not rub wax while it is still soft, or you will just spread it further. Wait until it hardens, then ease it off carefully with a wooden or plastic scraper held flat against the surface. A metal knife will scratch even shiny granite. Wipe off any thin film that remains with warm water and a soft cloth. On marble, the grease in the wax can soak into the pores and leave a dark mark, so on white stone always put a candle in a holder or lantern.

Rust stains

Brown rust streaks appear wherever a metal railing, vase, candle holder or old fixing touches the stone. Rainwater carries the rust onto the stone and it works deep into the pores. Such a stain is hard to remove, and most household rust removers contain acid that ruins marble instantly and can also attack the binding minerals in granite. So the first step is to deal with the source: replace or repaint the rusting item. Leave the stain itself to a specialist who can choose a product suited to that particular stone.

Gilded and painted lettering

Carved inscriptions usually get a coat of gold, silver or white paint inside the cuts, and occasionally real gold leaf. This layer is very thin and cannot stand up to rubbing. Do not scrub the letters with a brush: it is enough to pour clean water over them from above and touch them gently with a soft sponge. Do not put soap or any other product directly on the lettering. If the paint is already flaking or the colour has faded, repainting is a job for a craftsman, who will remove the old layer and restore the letters evenly. Amateur repainting often leaves drips on the stone.

The photo-ceramic oval

A photo-ceramic portrait has a surface as smooth as glass, and dust wipes off it easily. Use a soft cloth and clean water, then dry it with a clean cloth so no streaks remain. Abrasive products and rough sponges turn the surface matt. While cleaning, do not press on the plaque or grip it by its edges: if the adhesive has aged, extra force could pull it off. If the oval wobbles, its edge is cracked or a gap has opened up behind it, that is your cue to call a craftsman. For replacing or restoring the photo, see the photo-ceramic and portrait engraving page.

Bronze letters and patina

Bronze letters and fittings darken over time and sometimes take on a greenish film. This is patina, a natural protective layer on the metal, and there is no need to remove it completely. Many families actually prefer that dark, quiet tone. Wash bronze with water and neutral soap using a soft cloth, and dry it thoroughly. Polishing with an abrasive paste brings back the shine for a while, but it strips the protective layer, and the metal then gets dirty faster. If green streaks are running from the bronze down onto the stone, that needs a professional.

The usual causes of damage to stone

• vinegar, lemon and any acidic product, especially on marble;
• bleach and chlorine-based solutions, which change the colour and leave salt behind;
• scouring powders, rough sponges and wire brushes;
• scraping wax or moss off with a metal knife or a screwdriver;
• high-pressure water on old, weathered stone;
• de-icing salt in winter;
• an all-purpose cleaner of unknown origin whose ingredients you do not know.

Stains and how to clean them safely

How often to clean

A light clean - rinsing off dust and clearing away leaves - can be done on every visit. A thorough wash with soap is usually enough for granite two or three times a year, for example in spring and autumn. Marble needs a little more attention, because dirt sinks into its pores faster, especially under trees. Cleaning too often is harmful as well: every bit of rubbing wears the surface down a fraction. What to do at each time of year is covered in detail in our article on seasonal grave care.

When it is better to bring in a professional

Some tasks are beyond a family tidy-up. Granite that has lost its shine needs repolishing with specialist equipment. Marble needs resealing every few years, which closes the pores and protects against staining. Restoring faded lettering, removing deep rust stains, filling cracks and refixing a photograph are also jobs for a craftsman. If you rarely get to the grave, regular cleaning can be handed over to a care service: details are on the grave care page.

Frequently asked questions