Air Duct Repair in Simi Valley, CA

Weak airflow from one register, and dust you keep wiping

One room runs warm. The register barely moves a tissue. Usually that branch is flex, and flex fails in predictable ways. The inner liner pulls loose at the collar. Air then fills the outer jacket instead of the room. Or the run sags between joists and kinks over a truss chord. Attic heat cycling across decades loosens the tape and mastic at those collars. Simi Valley tract homes from the 1970s forward sit squarely in this pattern, with the horizontal furnace and coil up in the attic.

Repair starts with a visual trace of the whole run, not just the boot. We check collar connections at the plenum and support strap spacing. We also check whether the liner has torn free. A torn liner sheds insulation fiber into supply air. That is the gritty film on furniture that returns a week after cleaning.

Return side gets inspected too. A single undersized central return pulls attic and wall-cavity dust past a loose filter rack. Sealing the rack and the return plenum often changes more than patching a supply branch.

Some runs are not worth patching. Crushed flex with compressed insulation, or ducting with rodent nesting debris from hillside attics, gets replaced rather than taped. Patching a failed liner moves the leak downstream.