Duct Sealing in Bonita Springs, FL

Why your registers sweat, whistle, and never cool the back bedroom

Most duct leaks here are not holes in the middle of a run. They are at joints. The boot above a ceiling register separates from the drywall. The drawband on a flex collar loosens and the inner liner slides back off the takeoff. Ductboard plenum seams open where the staples and foil tape let go. Air handlers in hot garages and low attics make this worse, because the cabinet and the first few feet of trunk carry the highest pressure.

A leaking supply dumps cold air into an attic. A leaking return does the opposite. It pulls hot, humid attic air into the blower. Insulation fiber and fine sand come with it. That is what loads a coil and stains the ceiling around the grille.

Sealing means mastic and mesh at seams, mechanical drawbands on flex inner liners, then the R-6 or R-8 jacket and vapor barrier closed back over it with UL 181 tape. Skipping that outer layer invites condensation on the cold metal collar.

Crushed or torn flex should be replaced, not taped. Ductboard with soft, discolored liner is past sealing. We will say so rather than mastic over a failing duct.