Roof Dryer Vent Cleaning in San Jose, CA

Why does a roof vent clog faster than a sidewall run?

Gravity works against you. Second-floor laundry rooms push 20–35 ft of duct straight up to a roof jack. Lint that doesn't make it out falls back down. It collects at the first elbow above the dryer and inside the jack's flapper. Damp lint there sets like felt. The dryer top goes hot to the touch, and towels need two cycles.

The run gets brushed both directions: rotary brush from the roof down, vacuum at the laundry end. Clearing only the first few feet accomplishes nothing on a vertical stack. Roof condition decides the approach. Concrete tile cracks underfoot, and steep pitch limits what can be done safely from above.

Roof jacks are also nesting sites. Birds and rodents get into un-screened hoods, common in foothill and orchard-edge neighborhoods. A nest sits on top of packed lint and has to come out whole, not get pushed down the duct.

Two things change the job. Booster-fan homes with a failed fan usually have a packed line behind it. Flat-roof Eichler and mid-century houses have no attic at all, so the duct runs in a soffit or through a post-and-beam wall instead of up to a jack.