QUESTION

Cleaning Brown Stains off Exterior Tile - How to most effectively clean white Vitrified ceramic tiles in outdoor area, stained brown grey colour especially closer to grout area?

ANSWER

ANSWER - Normally brownish stains on tile in an exterior area are organic based caused by leaves or other plant materials that have deteriorated.  The fact that it is near a grout joint may be because the grout joints are low points of the floor where water collects perpetuating the deterioration of the organic matter.  Regularly applying a suitable penetrating sealer over the tile and keeping the surface clean will help prevent this problem in the future.

There are commercial poultices that can be purchased through manufacturers of cleaners for ceramic tile and stone that can remove deep stains.  There is a list of some these manufacturers on our website at www.CTaSC.com under Expert Answer's Resources on the cleaners and sealers page. Miracle Sealants has poultices and other cleaners.

Do not use anything acidic to clean these stains as they might cause problems.  You can experiment by taking a neutral based liquid cleaner and soaking the area for 5 minutes or so.  Then use a detergent with a soft bristle brush to scrub it.  Then flush it with clean water.  Always test the cleaning method you use first to make sure you are getting desirable results.  Good luck.