What is used to protect concrete walls against graffiti such as crayons, marking pens, spray paint, charcoal chalk and lipstick? We are concerned about a pedestrian tunnel where there will be ample opportunity for passers-by and loiterers to express themselves.
There are a number of coatings that protect the concrete and are easy to clean. Many of these are epoxy coatings but other types of coatings are also used. We suggest consulting a manufacturer of epoxies or other tile-like coatings.