Some dryer vent problems have nothing to do with how much lint has collected. The vent itself, the material it is built from, how the sections are joined, and where it exits the house, can each create a fault that no amount of regular cleaning will fix. A short look at the hardware tells you which one you are dealing with, buildup or the setup itself.
Start with the exterior vent hood
Step outside and find where the run exits the house. The hood should sit flush against the wall or the roofline, with a flap that swings open while the dryer runs and falls shut when it stops. A hood that is cracked, hanging loose, or missing its flap lets pests and weather into the duct between loads, on top of whatever it is doing to airflow.
Hoods placed close to the ground, under a deck, or behind shrubs collect leaves and yard debris from outside as well as lint from inside, narrowing the opening from both directions at once. On brick or stucco homes, common across older Elizabeth neighborhoods, the hood sometimes sits at an odd angle where the siding was patched around it, which keeps the flap from sealing the way it should.
What kind of venting material you have
Not all vent material behaves the same way. Rigid or semi-rigid metal lets lint move through smoothly, while flexible foil or vinyl accordion style venting has ridges that catch it at every turn. Many older New Jersey homes, particularly in towns like Bloomfield and Nutley where laundry rooms were added to a basement long after the house was built, still run on that older flexible material. If yours is one of them, it is worth having evaluated, since a cleaning helps but does not change how readily the material holds lint afterward.
Plastic vent material is a separate concern. Most codes bar it from dryer venting because it can warp or ignite under heat, so finding it during an inspection points at the setup itself rather than at how clean it is.
Signs of a poor connection or a damaged run
Sections taped together, held with a single screw, or sagging visibly between the dryer and the wall are signs of a joint that was never properly made. A crushed length, usually found where the duct gets pinched behind the dryer or squeezed through a tight gap in a floor joist, restricts airflow at that one point however clean the rest of the run is. Those are hardware faults, and a standard cleaning leaves them exactly where they are.
Why these signs do not clear up with a cleaning
The difference between a dirty vent and a damaged one decides the fix. A dirty run with sound hardware responds well to a thorough cleaning and performs normally once the lint is out. A run with a cracked hood, a crushed section, or the wrong material can be cleaned as thoroughly as you like and still dry clothes the same way afterward, because the restriction was never lint. Knowing which one you have before booking a visit sets the right expectation for what that visit will fix.
Pests and nesting inside the vent
A missing or broken flap is the usual entry point for birds, squirrels, and insects looking for a warm, sheltered space. Watch for nesting material at the opening, a sudden clump of lint near the exterior end of the run, or scratching sounds near the vent while the dryer sits idle. Once something has nested inside a duct, clearing it safely takes more than a single pass with a brush.
Three checks cover most of this: look at the hood while a load is running, put a hand on the transition hose behind the dryer, and follow the run as far as you can see it. If any of the three looks wrong, a dryer vent cleaning that includes a full inspection will tell you whether the fix is lint or hardware, and dryer vent installation is the answer when the material itself is what failed.