How to Clean Weathered Gravestones
You may be tempted to clean a gravestone often to keep it looking new. But Camille Bowman, architectural conservator, says this approach will erode gravestones prematurely. Instead, clean gravestones every 10 years or less and use the gentlest approach possible. Gravestones are most commonly made from granite, marble, limestone or sandstone. Before cleaning a weathered gravestone, find out what material it is made from.
Inspect the gravestone for damage. Don't clean a gravestone that has flaking, crumbling or cracked surfaces. You will further harm the stone.
Fill a pump sprayer with warm water and spray the gravestone. Scrub debris gently with a scrub brush, using a random scrubbing pattern. Start at the bottom and work your way up to avoid streaking. Rinse the weathered gravestone with water to remove loosened debris.
Dilute non-ionic detergent with warm water as directed on the package. Scrub the gravestone, applying the detergent with your scrub brush. Rinse clean immediately.
Apply a biocide cleaner to the weathered gravestone as directed in step 3. Apply the biocide cleaner to a wet or dry surface. Biocide cleaners kill fungi and other organic growth without damaging the rock. Wait five to 10 minutes and rinse thoroughly.
Things You Will Need
- Pump sprayer
- Soft-bristled plastic or natural brush
- Non-ionic detergent (photography product available online)
- Biocide solution
- Photograph the gravestone before and after you clean it.
- Consult a conservator before cleaning damaged or historically significant gravestones.
- Never move or discard gravestone fragments.
- Never use chlorine bleach on gravestones. Doing so can permanently stain the stone.
- Be careful when working around gravestones. They are heavy and often unsecured.
- Wear rubber gloves and eye protection when using biocides and non-ionic detergent.