Duct Sealing in Cape Coral, FL

What actually leaks in Cape Coral duct systems

Start at the boot, not the trunk. Lift the register. Look at where the boot meets drywall. In Cape Coral, that gap usually opens on slab-built homes where the supply drops through a ceiling. Attic air enters there. It carries fiberglass fines and roof grit. Gray streaks around the register grille are the tell. Homeowners blame the filter. The filter is innocent.

Flex duct failure here has a signature. The inner liner is banded. The outer jacket is not. So the vapor barrier hangs open at the collar. Humid attic air condenses on the cold core. Insulation sags wet. The run sweats onto ceiling drywall and someone calls it a roof leak.

Cape Coral's canal-side humidity makes this worse than inland Lee County. Attics here stay loaded. Builder-era homes on concrete slab with interior air handler closets often use the closet itself as return. That closet is rarely sealed to the slab. It pulls garage and wall-cavity air.

Mastic with fabric mesh. Draw bands on both liner and jacket. Boot-to-drywall sealed from inside the attic when access allows. Mold on bare ductboard is not a sealing job. That run gets replaced.