could be acid damage as well. I would first test it for moisture and see if that is the problem. If it is, than you it may be a problem since it is an exterior application and water will continue to be a problem.  if its acid damage it may be repairable..maybe.  Test it first and see what it is.  DO NOT try sealers or color enhancers..this will only make it worse

On Tue, Feb 7, 2012 at 8:09 PM, Lorne Greenberg <> wrote:

These tiles were put down 5 years ago and only about 6 months ago began
showing this.  I believe it is the sediment (salts, etc..) finally coming
through after the years of getting wet and drying out.  Is this correct? All
they have tried is acidic cleaners (strong ones) Either way, what is it and
how can it be fixed?

Lorne Greenberg
Fabra Cleen
"Getting all the dirt since 1949."
212-777-4040, 718-776-3564

Powered by
Visit list archives, subscribe, unsubscribe or change your subscription preferences:
Start a new conversation (thread):

Frederick M. Hueston PhD

Recommended stone care products

Many of my articles can be found at
Listen to my radio show
office             321 514 6845      
See my specialty products at