Air Duct Repair in Los Angeles, CA

What duct repair actually involves in Los Angeles homes

One room stays hot. The vent breathes weakly. Maybe you hear a whistle at the hallway grille, or the attic smells like something died in it. Those are different failures. A detached flex boot dumps cooled air into the attic. A single undersized return whistles because velocity is too high. Odor usually means rodent nesting inside the flex, or wet liner near an overflowing secondary pan.

Repair starts at the boot, not the register. Flex pulls off the collar when mastic was skipped and only a zip tie held it. We also look for crushed runs lying across ceiling joists and long sags between supports. Sag kills airflow quietly. Nobody sees it from inside the house.

Older trunk lines are a separate question. Original 1950s and 60s rigid galvanized often carries grey or black tape at the joints. That tape can contain asbestos. We do not scrape, sand or cut it. Testing comes first, then abatement by others if needed.

Patching makes sense when the metal is sound and damage is local. It stops making sense when fiberglass ductboard plenums are shedding, when coastal rust has opened the seams, or when the return was never sized for central air. Replacing a few feet of a bad design just moves the problem.