"Valley Green" (Black Mold)
It is a greenhouse down here. The heat and humidity never quit. The stone sweats.
This breeds "Valley Green." It usually looks black. It isn't just surface dirt. It is a plant that roots into the granite pores. People searching for headstone cleaning services near me usually want to blast it with a pressure washer. That destroys the stone. High pressure forces the roots deeper. The mold grows back twice as thick in a month.
We use a biocide soak. It seeps into the rock. It kills the root system completely. The growth dies, turns brown, and rinses off with a garden hose.
Citrus Chemical Drift
Mission is citrus country. The orchards are close to the cemeteries. Sprayers run constantly.
Agricultural chemicals drift in the wind. They land on the headstones. They mix with the dust and create a sticky, oily film. It bonds to the polish. Rain won't wash it off; it just smears. If you leave it, the chemicals eat into the stone finish. Standard soap is too weak for this.
We use an industrial degreaser for grave site cleaning services. We strip that chemical film first. Once the oil is gone, we can wash the stone clean.
River Water Scale
The water here comes from the Rio Grande. It is hard and salty.
Cemeteries irrigate heavily to keep the grass alive. The sun bakes the water dry in minutes. The salt stays behind. It builds a thick, white crust on the base of the monument. It bonds like cement. Scrapers scratch the granite. We use a buffered acid wash for cleaning stone gravestones. It attacks the salt bond. We melt the crust back into a liquid and rinse it away.
Mud Dauber "Shadows"
The heat brings the wasps. Mud Daubers build nests under the edges of upright monuments.
They use red clay to build their tubes. Even after you knock the nest down, that red clay leaves a stain. It looks like a shadow on the granite. It won't wash off with water. We use surfactants to pull the clay particles out of the stone pores.
Sandy Loam Washout
The soil near the river is sandy loam. It drains well, but it moves fast.
When we get heavy tropical rains, the water moves the sand out from under the foundation. The monument loses support and starts to lean. Shoveling topsoil back under it is a waste of time. The next rain just washes it out again. For permanent tombstone repair and restoration, we pack the hole with crushed angular gravel. The gravel locks together. It supports the weight, but lets the water drain through without taking the foundation with it.