Air Duct Replacement in Houston, TX

Does all of it have to be replaced?

Usually not. Trunks and plenums often stay. Failures concentrate in the branches. Houston attics are full of insulated flex duct, R-6 or R-8, suspended over joists and frequently kinked, crushed, or sagging between supports. Sagging flex pools dust at the low point and kills static pressure. The fix is a new run, hung straight, strapped at close intervals.

The age of the house changes the job. Pre-1960 homes have galvanized sheet metal trunk with branch takeoffs, often with original or deteriorated internal fiberglass liner. That liner sheds. It does not clean back to good. 1960s-80s ductboard plenums and fiberglass-lined rigid runs crumble at the corners. Some 1950s-60s slab builds have under-slab ducts, prone to moisture infiltration and silt. Those get abandoned and rerouted overhead.

Boots and returns get looked at before anything is sized. Slipped boot collars dump conditioned air into the attic and pull attic dust into the return path. Unsealed return plenums and wall-cavity returns draw attic fiberglass, cellulose, insect frass, and gypsum dust to the blower. Flood-affected homes need boot, chase and lower-run inspection.

New duct on one undersized central return solves little. Velocity stays high, the filter bypasses, humidity stays up. When indoor humidity stays high, settled organic dust on duct interiors supports mold again. Return area comes first.