Duct Sealing in Phoenix, AZ

Duct sealing in Phoenix homes

One bedroom stays warm all afternoon. The hallway register barely moves a tissue. The system runs and runs. Often the air never reaches the room at all. It leaks out into a 160°F attic first.

Most leakage sits in a few predictable places. Flex gets zip-tied at the outer jacket only. The inner liner slides back off the metal collar takeoff. Boot-to-drywall gaps breathe into the ceiling cavity. On 1950s-70s block ranch homes with sheet metal trunk-and-branch, the drive cleats and S-slips open up and old tape curls off. Return side matters most. Unsealed framing cavities used as return drops pull hot, unfiltered attic air past the filter.

We seal with mastic and UL 181 foil tape at collars, plenum seams, boots and the filter slot. Cleaning comes before sealing, not after. Rooftop gas-pack and heat-pump homes get the roof deck transition and curb checked, since that short run hides a lot.

Some ducts should not be sealed. Torn inner liner shedding fiberglass needs replacement. Under-slab runs holding silt and moisture are a different matter. Abandoned evaporative cooler drops get capped rather than patched.