The Problem
A 12-storey office tower had damp drywall on the 3rd floor. Two plumbing contractors had opened ceilings, tested fixtures above, and found nothing.
Detection Method
Thermal imaging scan identified a 2C differential in a fan-coil supply line above the ceiling — a pinhole leak too small to drip visibly but saturating drywall over weeks.
Results
Repaired same week. No drywall removal beyond a small patch. Detection cost under $1,000. Estimated $15K+ in exploratory repairs avoided.