Dear Steve:
When it looks like mildew it is usually mildew. It couldn't be anything else anyway.
A light power-washing with a specialty product to remove mildew stain rated for natural stone like Mb-9 will take care of that effortlessly. Spray it on and let it sit there until the stains disappear. It may take up to 10 minutes. Feed some product if it dries. Repeat in the most stubborn areas if necessary.
Rinse thoroughly when done.
May I ask you now to please read and e-sign our Statement of Purpose at: http://www.marblecleaning.org/purpose.htm?
Ciao and good luck,
Maurizio Bertoli
www.marblecleaning.org – The
Only Consumers' Portal to the Stone Industry Establishment!
Article ID: 1374
Created On: Sun, Apr 13, 2008 at 5:59 PM
Last Updated On: Sun, Apr 13, 2008 at 12:00 AM
Authored by: Maurizio Bertoli [mail@mbstone.com]
Online URL: https://marblecleaning.org/knowledgebase/article.php?id=1374