Air Duct Repair in La Mesa, CA

When the back bedroom never cools, the duct is usually the reason

The thermostat says the system is running. The farthest register barely moves a tissue. That pattern points at the duct, not the condenser. In La Mesa attics we usually find 1970s–90s gray or silver flex, kinked over a joist or sagging in a long belly. Inner liners crack and shed with age. Sometimes the boot has pulled off the register take-off entirely. Conditioned air then dumps into the attic, and attic dust and insulation fiber ride back into supply air.

Repair starts with a look, not a guess. Static pressure, register-by-register airflow, a crawl along the runs. Original 1950s–60s galvanized trunk-and-branch often seals and survives fine. Where pre-1960 plenums carry paper and tar wrap, we handle it intact and do not disturb it.

Other findings change the plan. Rodent nesting shows up in crawlspace and attic runs on the rural east side. Supply plenums sweat on marine-layer mornings. Low-lying crawlspace runs stay damp longer than anyone expects.

Some duct is worth repairing. Some is not. If a flex run is brittle enough to crumble at the collar, patching it buys you one season. We will say so instead of selling tape.