Roof Dryer Vent Cleaning in San Antonio, TX

Why does the upstairs dryer vent always end up on the roof?

Because the builder took the shortest path. In 1990s-and-newer two-story homes here, the laundry sits upstairs. The duct goes up through the attic and out a roof jack. That makes a long run. Code caps the equivalent length at about 25 feet, and every elbow eats into that budget. Plenty of these runs were installed with no booster fan at all.

Roof terminations fail in their own ways. The flapper gets propped open by packed lint. Birds nest behind it. Wasps build in spring. Screened hoods are worse: lint and cedar pollen cement into a mat you cannot brush through from below.

Cleaning one end does not finish the job. Lint knocked loose from the roof falls back down the riser. The run gets brushed and vacuumed from the laundry side too. While the attic is open, the joints get checked. Disconnected joints dump lint straight onto insulation, and gray fuzz on top of the batts is the tell.

Check it yourself. Run the dryer and look at the roof flap from the yard. No movement means a blockage, not a weak dryer. Towels needing two or three cycles in August humidity point the same direction. Long roof runs, pets, or big households want attention every six to nine months.