Thin Veneer over painted stucco - What COde Applies?

​I am looking for guidance and I am hoping your organization can point me in the right direction.

I had a home originally built in 1972 extensively remodeled (90%+) in 2012 and brought up to what I believe were 2007 Florida Building Codes. Recently the home has experienced catastrophic failure of the stone facade. I am in the process of exploring my options as it relates to construction defect and I have had several masons come asses the damage. The mason who originally did the work is no longer in business, but the GC who re-built the home is. I am trying to identify in code where the missteps were in the installation. It appears that a scratch coat was applied directly over an unclean and painted stucco (original to the 1972 home) surface (see photos). In time, this has resulted in a de-bonding of the scratch coat and the stone facade and mortar falling off the home, exposing the original painted stucco. My limited understanding is that this would have been a violation of ASTM C 926 reference 5.2 “...and shall be free of form oil or other elements, which would interfere with bonding.”. I have had masons who have inspected the damage who also bring up that it does not appear a bonding agent was used. At this point the GC is wanting to simply remedy the failed area with new stone and admit no fault. However if the entire stone facade was installed using the same incorrect methods (see pictures) it is just a matter of time before the bond fails. Furthermore, I think it is unlikely that the GC will be able to match the stone as it was manufactured stone with pigmentation that has been baking in the FL sun for nearly 8 years. My ask is, if you could advise on what codes may have been violated with this installation and / or if you have a recommendation of an engineer / GC (based in N C FL) that I could hire to document said violations? I appreciate your time in reading my story, reviewing photos, and consideration of a response.

Thank you for contacting the Masonry Association of Florida with your concerns. You are correct that it appears that the Scratch coat of mortar has de-bonded or delaminated from the original painted stucco. While paint is good weather proofing it will also prevent cementitious material from bonding. Here are some considerations that need to be included in any repair discussion.

1. Simply replacing the fallen stone with the existing stone will not work. Cleaning the mortar from the existing stone could result in much damage to the stone and loss of a considerable amount of stone. 
2. Replacing the fallen stone with new stone will not work even if the original producer is still manufacturing the same stone. There is an 8 - 9 years difference in age and there will be a color difference.
3. Since it appears that the manufacturer's installation guide was not followed a shear bond strength test would have to be performed to determine the strength of the bonding of the mortar to the substrate.
4. It appears not to meet the current building code and standard practice for adhered thin veneer. That would probably have to be remedied.

I wish you the best of luck in resolving this issue. If we can be of further assistance please contact MAF. Be safe.
Jerry Painter, FASTM