Before Leakage Test

Use this before duct gets tested so the obvious leak points are not missed.

The system is near pressure/leakage test, inspection, TAB, startup, or punchlist.

Ask when a leak is caused by bad fit-up, wrong material, missing gasket, damaged flange, access door issue, or when the test requirement is unclear.

Do not smear mastic over a bad mechanical joint and call it fixed.
Do not seal over loose screws, missing gasket, missing corners, or misaligned flanges.
Do not cover damper labels/access points.
Do not assume pressure-test requirements are the same on every job.

Walk the system and check mechanical joints before throwing sealant at everything.
Check flanges/TDC/Ductmate corners, gasket continuity, cleats/bolts, and joint alignment.
Check S-and-drive corners, slips, drives, and open seams.
Check takeoffs, collars, spin-ins, access doors, dampers, equipment connections, and end caps.
Clean dirty/oily surfaces before sealant or tape.
Confirm which sealant/mastic/tape/gasket is approved for the job.
Document suspect leak points before test if you need direction.