For an experienced technician equipped with the proper tools, dryer vent cleaning is generally a straightforward affair. As with any activity, however, add a good deal of height to the mix and said activity becomes a great deal more challenging.
Dryer vent cleaning companies will usually add a hefty surcharge for a rooftop job—and with good reason. Danger (and liability) increases greatly due to the potential for injury caused by the height itself, a steep pitch, a slippery surface (e.g. cedar shake roofs), or weather (ice, rain, etc). Let's face it, builders did not necessarily have hapless dryer vent cleaners in mind when they designed homes with second-floor laundry rooms. Luckily, however, those sent to tackle the job are well experienced and appropriately equipped.
The process of rooftop dryer vent cleaning
Before beginning the cleaning, the technician will run the dryer on air-only, checking to make sure the machine is working properly, that all connections are secure, and that there's no air loss or disconnects anywhere behind the dryer.
Once he's safely reached the rooftop, he'll check the vent itself for proper air flow (the machine has been left running on air only). If the vent line is clogged, air flow would understandably be diminished or non-existent. He begins the cleaning process by inserting a spinning, reverse-blowing air ball, attached to an air line, down the vertical duct through the vent line to the back of the dryer itself. Then, using a long-handled air trigger, he cleans the hood and damper portions of the exhaust. The inner hood and the area around the damper tend to become clogged with lint that has been hardened from exposure to successive summer heat and winter cold.
The process of cleaning this area will probably result in some larger compacted lint chunks falling down the vertical vent line, beyond which sits the reverse-blowing air ball, waiting to do its job. Once the tool is engaged, the technician will pull and push it up and down the vent line, while its reverse-blowing air nozzles blast lint out toward the vent opening. This process is repeated until no more lint is expelled, and the technician is able to observe good air flow pushing through the vent.
The limitations of alternative methods
It should be noted that it is nearly impossible to thoroughly clean a rooftop dryer vent from anywhere other than the rooftop. If attempted from down below, or from the attic, cleaning can be partially accomplished and decent air flow can even be achieved, to the point where the dryer runs better and more efficiently. However, the cleaning cannot possibly be complete or as thorough using this method as when performed from the rooftop, and a re-clean will be necessary sooner. Why? Because you cannot get around the damper from behind it. In fact, cleaning a rooftop vent from down below can quite possibly make the situation worse, by pushing all the debris up toward the damper without being able to completely push it out, causing a more stubborn clog.
An unfortunate byproduct . . .
As shown in the photo above, a lot of lint can accumulate in a rooftop dryer vent (or any dryer vent for that matter). The technician will bag the larger pieces, any chunks he removes manually, and anything nearby that can be grabbed. However, due to the velocity of the lint blasting out from the vent line from the spinning air ball and the distance it often travels, it is nearly impossible to contain completely. The tech will typically use his air trigger to ensure no lint comes to rest in the gutters, and to disperse that which remains elsewhere (it is biodegradable after all), but to capture all of the lint expelled is an impossible task, particularly when weighed against the importance of remaining focused, steady, and safe at such a height.
Wanna dig deeper? Download our free tipsheet: 5 Questions to Ask Before Hiring a Dryer Vent Cleaning Company.
Many thanks to our technician Ben S for lending his expertise to this article.