CAUSE:
- Moisture penetration into substrate
- Failure of the old tile adhesive
- Vibrations and other mechanical stresses by an earthquake or other causes
TREATMENT:
- Remove the detached or cracked tiles
- Remove any remnants of the old tile adhesive from the substrate or existing tiles
- Allow the substrate to dry from moisture
- Reinstall existing or new tiles using flexible tile adhesive
- Grouting with the appropriate grout, depending on the width and depth of the joint