Air Duct Replacement in San Juan Capistrano, CA

When does flex duct need replacing instead of cleaning?

Ask that before anyone quotes a job. Cleaning restores a duct that still holds its shape. Replacement is for duct that cannot. Torn inner liner is the usual verdict. So is a crushed radius elbow feeding an end-of-run bedroom. Sagging flex between truss bays pools dust at the low points. A sagged run with a split liner will not recover. Pre-1975 homes here sometimes still have rigid sheet metal trunks with fiberglass duct board plenums. Aging binder sheds fibers. That plenum gets rebuilt, not vacuumed.

Replacement in San Juan Capistrano attics means R-8 insulated flex on newer work, versus the R-6 common on pre-2000 installs. Runs get supported at proper intervals so they stop drooping. Boots and collars are sealed with mastic, not duct tape, because tape at boots is what failed in the first place.

Coastal homes add corrosion. Salt air eats registers and metal collars within a few miles of the beach. Hillside grading drives fine mineral dust and silica into every seam. Marine-layer months leave condensation and surface mold at supply boots in bathrooms and north-facing rooms.

Unsealed platform returns pull attic air. Fix that and the filter grille sizing, or new duct just redistributes the same dust.