QUESTION:

I have a old building that was built with natural stone and has turned black over the years. Can I clean it without hurting the stone? Can I stop the black from returning?

PICTURE:

SOLUTION:

The picture above shows an old limestone wall that has the symptoms that you described. The bottom section was cleaned with BioKlean by PROSOCO. To minimize the black returning, apply Weather Seal Natural Stone Treatment by PROSOCO. The black staining is usually mold, mildew and atmospheric stains. By making the stone less absorptive, you will minimize future staining.

SUPPLIERS:

www.prosoco.com Link to the service provider page