Duct Sealing in Houston, TX

Duct sealing on Houston attic and crawlspace systems

One room never keeps up. The register moves air, but weakly. Dust comes back a week after cleaning. Usually the air leaks before it reaches you. In attic flex systems, the usual culprits are the collar connections at the sheet-metal or ductboard plenum, where the inner liner has pulled back off the fitting. Boots also leak at the ceiling, straight into the attic cavity above the drywall.

Foil tape alone does not hold in a Houston attic. Heat and humidity cook the adhesive, and the outer jacket sweats. The fix that lasts is mastic on the inner liner, a proper draw band, then the insulation and vapor jacket pulled back over and banded separately. Miss that second band and you get condensation inside the wrap.

Returns matter more than supplies here. Panned-joist returns in older pier-and-beam bungalows around the Heights and Montrose pull crawlspace air by design. Sealing supplies only, on an already undersized single central return, raises static pressure and makes the whistling worse.

Some ducts should not be sealed at all. Crushed flex, torn liner, rodent-chewed runs, rusted ductboard at the plenum (mastic on those is wasted effort). Replace the run instead.

Ask for a pressure-pan reading or duct leakage test before and after. That number is checkable.