Duct Sealing in Simi Valley, CA

Duct sealing in Simi Valley homes

The back bedroom never cools. Dust returns a week after cleaning. The system runs long and the attic above feels warm. Those three symptoms usually trace to the same place: leaking connections between the furnace, the plenum, and the flex branches. In most 1970s-forward tract homes here, that equipment sits horizontally in the attic. Conditioned air escapes into a hot attic. Attic air gets pulled back in.

The leak points are predictable. Flex collars loosen after decades of attic heat cycling. The inner liner separates from the boot and insulation fibers ride into the airflow. Cloth tape from the original build dries out and lets go. Return plenums often leak worst, because a single undersized central return pulls hard enough to draw dust through wall cavities and past a loose filter rack.

Sealing means mastic on every collar and seam. Mechanical fasteners go at each connection. The plenum box gets addressed too, not just the easy runs. Crushed or sagging flex gets re-hung before sealing. Sealing a kinked run accomplishes nothing.

Some ducts are not worth sealing. Torn liner means replacement. So does rodent contamination or brittle sections. We say so on site. Crawlspace runs in older homes get their own look.