Air Duct Replacement in Bodega Bay, CA

When is replacing duct better than patching it again?

Patching works on joints. It does not work on a failed duct body. Mastic and tape seal seams. They cannot restore a crushed crawlspace run. They cannot fix flex with a torn inner core. Rodent-chewed insulation is replacement work, not repair work. The honest line is whether the duct still holds its shape and its jacket.

Bodega Bay has two duct populations under one roof type. Pre-1970 homes run galvanized trunk-and-branch through the crawlspace under raised foundations, and the original wrap is often deteriorating. Tract construction from the 1980s onward uses insulated flex in the attic. That flex sags and kinks over framing. Stored boxes compress it further. Old farmhouses and later additions have retrofit ducting squeezed into odd cavities.

Fog and marine air change the math near the shoreline. Cold supply duct sweats. Mold shows on the jacket, not inside the metal. Boots pull loose from the subfloor and dump conditioned air under the house.

Replacement starts at the return, not the registers. Undersized filter slots and leaking plenums draw crawlspace and attic air straight into supply. Sheet metal transitions get fabricated off-site. New runs get strapped at proper spacing so they never sag again.

Pull a register and look for gray fiber streaks. That tells you a lot.