Why roof leaks are harder to find than you think
Roof leak detection is the work of finding the entry point before anyone touches the roof. Water travels laterally. The stain on your ceiling is rarely directly below the breach in your membrane. Water enters at one point, travels along decking, insulation, or structural members, and appears somewhere else entirely. Patching where you see damage almost never stops the leak.
Commercial flat roofs compound this problem. Multiple penetrations, equipment curbs, drain connections, and parapet interfaces create dozens of potential entry points. Without systematic commercial roof leak detection, you're guessing — and guessing means repeat service calls, continued water damage, and escalating repair costs.
Common leak sources we diagnose
Membrane Failures
Seam separations, punctures from foot traffic or equipment, and blistering from trapped moisture. We identify the specific failure mode to specify the right repair.
Flashing & Skylight Leaks
Every pipe, vent, skylight and HVAC unit penetrating the roof is a potential leak source. Failed sealants, improper lapping, and corroded metal all contribute — skylight leak repair and curb reflashing are among our most common calls.
Roof Flashing Repair
Counterflashing, reglets and through-wall flashing are the first thing we check and the most common roof flashing repair we do. Once roof leak detection points to the flashing, we rebuild the detail rather than resealing it.
Drainage Deficiencies
Clogged drains, inadequate slope, and failed scuppers create ponding that accelerates membrane deterioration and forces water through weakened areas.
Wall & Parapet Junctions
Where roof meets wall is a chronic leak source. Through-wall flashing, counterflashing, and coping connections all degrade over time.
Recent NYC projects
Root-Cause Leak Diagnosis
Our roof leak detection starts with a comprehensive roof survey — visual inspection, drain testing, and condition documentation. We trace water pathways from the visible damage back to the point of entry using systematic elimination.
When visual inspection isn't conclusive, we employ infrared roof leak scanning to identify trapped moisture in insulation and decking. Core sampling confirms conditions beneath the membrane. This diagnostic approach means we repair the actual source, not a best guess.
When we identify an active leak, we schedule promptly, trace it to the true source, and execute a permanent repair — not a stop-gap. One thorough fix beats repeat service calls.
What NYC building owners say
Active leak? Call now.
Free diagnosis for NYC. We find the source, not just the symptom.
Frequently Asked Questions
Stop chasing leaks. Find the source.
One thorough diagnosis beats ten patch attempts. Let us find it and fix it right.
Related: Roof Leak Repair NYC