Industrial Soot and Black Crust
Wilmington has a long history of industry. For decades, factories pumped smoke into the valley. That sulfur settled on the limestone and marble headstones.
It turns into a hard, black scab. It fuses with the stone surface. Rain runs right over it. Families looking for headstone cleaning services near me often try to scrape it away with a knife. That rips the face right off the marble. We use chemical poultices. We soften the crust gently. We draw the pollution out without stripping the monument.
Winter Freeze-Thaw Damage
Delaware winters are wet and freezing. Water gets into hairline cracks in the granite and marble. When it freezes, it expands.
It acts like a wedge. It splits the stone or pops the face right off. We call this spalling. You see it as piles of chips at the base of the marker. We inspect for these cracks before winter. We seal them to keep the water out. Prevention is the only way to stop the ice from breaking the stone apart.
Valley Moss and Algae
The Brandywine Valley is damp. Fog hangs low near the river. In shaded cemeteries like Cathedral or Riverview, the sun doesn't dry the stones out.
Green moss and black algae take over. They cover the inscriptions completely. This isn't just cosmetic; the roots hold water against the stone, making freeze damage worse. We don't pressure wash this. It is too risky on old stone. We use a biological biocide. We kill the growth down to the root. It dries up and falls off, leaving the stone clean and readable.
Road Salt Spray
Salt trucks are busy here from December to March. The spray from the roads hits the cemeteries along the perimeter. Salt eats masonry.
It soaks deep into the pores. When it dries, it expands inside the rock. It pushes the stone apart from the inside out. On the surface, it looks like white powder. We use a drawing poultice for grave site cleaning services. We suck the salt out. We flush the stone to stop the rot before the surface crumbles away.
Wet Leaf Rot
We have big deciduous trees here—oaks and maples. In the fall, they drop tons of leaves. Wet leaves stick to flat markers like glue.
They sit there all winter, rotting under the snow. They release tannins that stain the stone dark brown. If you leave it, the acid etches the polish. We clear this debris before the snow falls. We treat the organic stains with a solvent that lifts the brown color out of the granite pores.
Sinking in Soft Ground
The freeze-thaw cycle also messes with the soil. The ground heaves in winter and sinks in spring. Heavy monuments shift.
We see headstones leaning dangerously. Adding dirt on top doesn't fix it; the ground is too soft. During cemetery plot maintenance, we lift the stone. We dig out the mud and put in a deep gravel foundation. Gravel drains well and doesn't heave like dirt. It keeps the monument straight through the winter.
Urban Grime
Being in a busy city, exhaust and road dust coat the stones in a greasy film. It makes polished granite look dull and hazy.
Water just beads up on it. You need a degreaser to cut through it. We scrub the stone with specialized surfactants for cleaning stone gravestones. We strip the traffic film. The natural shine of the granite comes back once the oil is gone.
