The Site-Assessment Checklist I Borrowed From a Conservator

headstone cleanning in Pennsylvania | headstone cleaning in California

I’ll never forget the first time I tried to clean a headstone without a plan, it was a hot July morning at Oakwood National Cemetary, and I’d just adopted a little Civil War-era marker for a private named Ezra Cole. Marble. Pretty beat up. I showed up with a bucket of water, a soft brush, and a bottle of D/2 Biological Solution I’d read about online. Felt confident. Real confident.

Twenty minutes in, I realized the stone had a deep crack I hadn’t noticed—running from the top edge right down through the name. Water and cleaner pooled in there, and I spent the next hour panicking, dabbing it dry with paper towels, praying I hadn’t made it worse. Took me three tries to get the moisture out. Worth it, but man, I learned my lesson.

That’s when I called a friend who works as a conservator at a big historic cemetery. She laughed—not mean, just that knowing laugh—and said, “James, you need a site-assessment checklist. You can’t just wing it.” She sent me hers. I’ve been using it ever since. I tweaked it a little for us volunteers, but the bones are all hers. Here’s what I use before I touch a single stone.

1. The Initial Walkaround: Look Before You Touch

This is where I pull out my flashlight and my 10x jeweler’s loupe—I bought it for $12 on Amazon, and it’s the best tool I own. I shine the light at a low angle across the stone. That catches every little bump and scratch.

I’m looking for:

• Previous repair attempts – old epoxy, cement patches, paint. If someone tried to fix it before, I need to know. Those repairs often fail and trap moisture.
• Graffiti – even faint pencil marks. Some folks think it’s okay to leave notes. It’s not.
• Surface texture – is it smooth, carved, or rough? Rough stone holds dirt differently.

I take photos with my phone. Lots of them. I use a ruler for scale. Then I write down everything in a little notebook I keep in my vest pocket. I don’t trust my memory. I’ve got the memory of a sieve.

3. The Material ID: Marble, Granite, or Something Else?

You’ve got to know what you’re dealing with. Marble is soft and acid-sensitive. Granite is tough but can still be damaged by harsh chemicals. Sandstone is like a sponge—it soaks up everything.

Here’s my quick trick: I wet my finger and press it on the stone for 10 seconds. If it feels like it’s drinking the water, it’s probably sandstone or limestone. If it stays beaded, it’s marble or granite. Not perfect, but it’s good enough for a volunteer.

I also look at the carving style. Is it hand-carved or machine-cut? That tells me age. Old hand-carved stones are more fragile. I’ll go easier on them.

And I never, ever use anything acidic. No vinegar, no lemon juice, no “natural” cleaners. I stick with a pH-neutral, non-ionic cleaner like D/2. It’s a biological solution—basically good bacteria that eat the lichen and moss. Works slow, but it works right.

4. The Environmental Check: Sun, Shade, and Weather

This part sounds boring, but it’s saved me more than once. I check:

• Sun exposure – if the stone is in full sun, I’ll clean early morning or late afternoon. Hot stone dries cleaner too fast, and you get streaks.
• Shade and dampness – shaded stones often have more moss. They also stay wet longer, so I plan extra drying time.
• Wind – seriously. If it’s windy, dust and pollen blow onto the wet stone and stick. I’ll postpone or work in sections.

I also look at the ground slope. If rainwater runs off toward the stone, that’s a problem. I note it for the cemetery staff. I can’t fix drainage, but I can tell someone who can.

Last thing: I check the forecast. No point cleaning if it’s going to rain in two hours. The D/2 needs at least 4 hours to work. I’ve had to pack up mid-job because I didn’t check. Rookie move.

5. The Final Go/No-Go Decision

This is the step I borrowed directly from my conservator friend. She calls it “the honest moment.” You look at your checklist and ask: Can I do this without causing harm?

If the stone is crumbling, has active delamination, or is covered in old repairs that are failing, I stop. I take photos, write a note, and pass it to the cemetery office. Some things are for pros.

But if it’s stable—just dirty, a little moss, no structural issues—I go ahead. I mix my cleaner per the label (never stronger), use soft brushes and wooden scrapers (plastic spatulas work great), and I work from the bottom up to avoid drips.

And I always leave a note on the stone with a date and my initials. Not required, but it feels right. Like saying, “I was here. I cared.”

That checklist? It’s my security blanket. I’ve used it on maybe 200 stones now. Never had a problem. Well, except for that one time with the wasps. But that’s a different story.

Frequently Asked Questions

Q: Can I use a wire brush on a headstone if I’m carefull?

A: No. Skip abrasive tools like wire brushes, steel wool, or even stiff nylon brushes on anything but granite. They scratch the surface, and those scratches trap dirt and moisture. On marble or sandstone, they can remove the original surface finish. Use a soft-bristle brush or a plastic scraper. I use a cheap nylon dish brush—the kind with the handle. Works fine.

Q: How do I know if a headstone is sandstone without a test kit?

A: The wet-finger test I mentioned works pretty well. Also look at the grain—sandstone looks, well, sandy. You can sometimes see tiny sparkly bits (quartz grains). And it feels rougher than marble. If you rub it gently and a few grains come off on your hand, it’s sandstone. Go easy on it.

Q: What should I do if I find a headstone with old cement repairs?

A: Don’t try to remove them yourself. Cement is harder than most historic stone, and it expands and contracts differently. Trying to chip it off can break the stone. Just clean around it carefully, and report it to the cemetery. They might have a conservator on contract. I’ve flagged three stones this year alone.

Q: Is D/2 Biological Solution safe for all stone types?

A: Yes, because it’s pH-neutral and non-ionic. It works by using bacteria to digest biological growth, not by chemical etching or bleaching. I’ve used it on marble, granite, limestone, and sandstone. Just follow the label: wet the stone first, apply the D/2, let it sit (don’t let it dry), then rinse. I use a garden sprayer with a gentle mist setting.

Q: Can I pressure wash a headstone to save time?

A: Don’t. Even on low pressure, a pressure washer can blast away softened stone, especially on old marble or sandstone. The water forces into cracks and causes freeze-thaw damage later. I know it’s tempting—I’ve been there. But hand-cleaning with a soft brush and D/2 is safer. Takes longer, but the stone stays intact.