Cleaning vs. Conservation: Why They're Not the Same Job
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A few summers back, I was out in a tiny cemetary outside of Stillwater, Oklahoma, it was about 95 degrees, I’d already gone through two bottles of water, and I was kneeling in front of a gorgeous 1880s marble marker for a woman named Eliza. The lichen was so thick it looked like green velvet. I had my spray bottle of D/2 Biological Solution, a soft nylon brush, and a wooden scraper. I started working — gently, methodically — and about twenty minutes in, a man walked up with a pressure washer. He was the groundskeeper. He said, 'Oh, let me just blast that for you, make it look new.' I told him no, thanks, I had it. He looked at me like I was crazy. But here’s the thing: what he wanted to do was cleaning. What I was doing was conservation. They sound similiar, but they’re worlds apart. One rushes in. The other holds back. That day, I saved Eliza’s face from being sandblasted off. Took me three tries to get the lichen off. Worth it. So let’s talk about what the difference between cleaning and conservation really means — and why getting it wrong can erase history forever.
What Cleaning Really Means (And Why It’s Not Enough)
Let’s be blunt: most people think cleaning a headstone means making it look brand new. Scrub hard. Use soap. Maybe bleach. Maybe a wire brush. Big mistake. Commercial cleaning, the kind you do on your kitchen counter, is about removing dirt fast. But stone isn’t tile. It’s porous, it breathes, and it’s been sitting outside for a hundred years. When I say "cleaning" in a genealogical context, I mean removing biological growth — moss, lichen, algae — and loose surface grime. Nothing more. I use D/2 Biological Solution because it’s pH-neutral and non-ionic. It doesn’t strip the stone’s patina. It doesn’t eat away at the surface. I spray it on, let it sit for 10-15 minutes (longer if it’s stubborn), then use a soft nylon brush and distilled water. That’s it. No pressure. No harsh household chemicals. No abrasives. The goal is to reveal the inscription, not to make the stone look like it was installed last week. Because if you over-clean, you damage the surface. And once that damage is done, it’s done.
Conservation: The Art of Doing Less
Conservation is a different mindset entirely. It’s not about making something look clean. It’s about stabilizing what’s there and preventing future damage. I think of it like an old book — you wouldn’t scrub the pages to make them white. You’d handle them carefully, store them right, maybe repair a tear. Same with stone. Conservation includes things like: assessing structural cracks (should I use a stone-safe consolidant? Or leave it alone?), resetting a leaning stone so it doesn’t fall, or applying a sacrificial poultice to draw out salts that are causing flaking. It also means knowing when not to clean. If a stone is already crumbling — what we call sugaring — cleaning it will just accelerate the decay. I’ve walked away from stones that looked dirty because touching them would of made them fall apart. That’s conservation. It’s humble. It’s patient. It’s the opposite of that groundskeeper with the pressure washer. He meant well, but his idea of cleaning would have destroyed Eliza’s stone in thirty seconds flat.
The Difference Between Cleaning and Conservation in Practice
Here’s a concrete example. Let’s say you’ve got a sandstone headstone from 1860 with black crust on it. That crust might be gypsum from air pollution. If you scrub it with a wire brush (cleaning), you’ll rip off the crust — and the soft sandstone underneath. The stone loses detail, maybe the whole face. If you use a conservation approach, you test the crust first. Is it stable? Does it hold together? If it’s loose, you might use a soft brush and distilled water to gently remove what comes off naturally. Then you apply a poultice of clay and deionized water to draw out the salts. You wait. You repeat. Takes days, not minutes. But the inscription stays readable. The stone stays intact. That’s the heart of the difference between cleaning and conservation: cleaning is aggressive and immediate; conservation is careful and slow. Both have their place. But on historic stone, conservation wins every time.
When Cleaning Becomes Conservation (And Vice Versa)
Sometimes the lines blur. For instance, if a stone has thick lichen that’s actually pitting the surface, removing that lichen is both cleaning and conservation. You’re taking off a harmful growth that’s actively damaging the stone. That’s a good thing. But the method matters. I’ve used D/2 on lichen for years, and it works because it kills the biological matter without harming the stone. That’s conservation-friendly cleaning. On the flip side, some people try to "conserve" a stone by slathering it in sealant. Bad idea. Sealants trap moisture inside, causing freeze-thaw damage. That’s not conservation — that’s a slow-motion disaster. So the real skill is knowing which approach fits the situation. I always ask: Is this action going to extend the stone’s life? If yes, it’s conservation. If it’s just making it look nicer for a photo, it’s cleaning. And sometimes, a good photo is fine — but be honest about what you’re doing.
What You Can Do at Home (Without Ruining Anything)
If you’re a family historian or a volunteer, you can absolutely clean headstones. But stay in your lane. Stick to gentle methods. Use only pH-neutral, non-ionic cleaners like D/2 (I buy it online, about $40 a gallon). Use a soft natural-bristle brush — I use a horsehair brush. Never use metal brushes, wire wheels, or anything abrasive. Skip strong acids or alkaline cleaners. They’ll eat the stone. Never pressure wash — even on granite, it can blast off patina and drive water into cracks. And for the love of all that’s sacred, don’t use bleach. Bleach leaves salts behind that crystallize and flake the surface. I’ve seen it happen. It’s heartbreaking. If you’re not sure, stop. Take a photo. Email a conservator. There’s no shame in asking. The shame is in ruining something that’s been standing for 150 years because you wanted to "clean it up" in an afternoon.
Frequently Asked Questions
Q: Is it ever okay to use a pressure washer on a headstone?
A: Short answer: almost never. On fragile stone like marble, limestone, or sandstone, pressure washing will erode the surface and blast away detail. On granite, it’s less damaging but still risky — it can drive water into cracks and cause freeze-thaw damage in winter. I’ve seen pressure washers leave pitted surfaces that look like acne scars. Stick to soft brushes and water. Your stone will thank you.
Q: What’s the biggest mistake people make when they try to clean a headstone?
A: Using bleach. I get why people do it — it’s cheap, it’s in the house, it kills mold. But bleach leaves behind sodium salts that get absorbed into the stone. When those salts dry, they crystallize and push the stone apart from the inside. I’ve seen marble flakes the size of postage stamps pop off because of bleach. Just don’t. Use D/2 or a similar biological cleaner instead.
Q: How do I know if a stone is too fragile to clean?
A: Touch it gently. If the surface feels crumbly or powdery (what conservators call sugaring), or if you see loose flakes, don’t clean it. Even a soft brush might pull off pieces. Also check for cracks — if water gets in, freezing can split the stone. When in doubt, call a professional conservator. It’s better to leave a stone dirty than to destroy it.
Q: Can I use vinegar or baking soda to clean a headstone?
A: No. Vinegar is acidic (acetic acid). It will etch marble and limestone, leaving a dull, rough surface. Baking soda is alkaline and can also damage stone. Both are fine for your kitchen, but not for a 19th-century marker. Stick to pH-neutral, non-ionic cleaners designed for stone. Your headstone isn’t a science experiment.
Q: What’s the difference between cleaning and conservation in one sentence?
A: Cleaning removes dirt and growth; conservation preserves the stone for the future. Cleaning is about appearance; conservation is about survival. One is a service, the other is a responsibility.