Good morning

  I am wondering if  anyone has experience with  exterior tile deck failures. I have  approximately 800 square feet of exterior deck surfaces covered in 16×16 porcelian tile. The home is located in SE Coastal North Carolina and faces the intracoastal waterway and a large marshy area. The deck surfaces are treated with Volcum 350, water proof membrane applied in liquid form, 1 1/2- 2  inches of mud set concrete,water resistant thinset, Schulter barrier , thiset and the procelian tile. A significant amount of brown to black material is leaching from the deck apparantly between the tile and the Schulter barrier.This material builds up on the deck facia and then drips on the ground to form a crusty brown caustic smelling substance. The best I can tel this is a breakdown of the thin set material, however my representative from  the source ,where the thinset was purchased,says this is impossible. I have located some information on latex leaching and this sounds and looks very much like what the problem is. Looking for some help with this problem.

Thanks Geoff