Natural stone is the material most often ruined by bad cleaning. It's porous, each type reacts differently and the damage is usually permanent.
Never do this
- Acids on limestone, marble or sandstone: they burn and stain.
- High pressure close up: it strips the surface and leaves the stone rough and more porous.
- Wire brushes: they scratch and leave rust marks.
How to clean it properly
Identify the stone, use pH-appropriate products, low-to-medium pressure with a wide nozzle and distance, and always test on a hidden area. For algae and lichen, a biocide with time to act before cleaning.
Protect it afterwards
A breathable water repellent reduces water, dirt and salt absorption without changing the look and lets the stone breathe.
FAQ
Can stone be pressure washed?
Yes, with low or medium pressure, the right nozzle and distance. Not with high pressure.