Cleaning lint buildup from roof vents is difficult and nesting birds and squirrels often find roof vent caps irresistible.
Outside dryer vent on roof.
Considering that back pressure higher than 6 wci is generally recognized as inefficient you can see that venting through the roof with non dryer specific vents is immediately problematic.
Run your dryer until no debris comes out of the outer vent making sure that the air flow is not restricted.
To make the dyer more efficient you can buy an inexpensive heat diverter and install it in the exhaust duct of electric dryers only not gas dryers you ll save about 50 worth of heat per load in the winter.
Dryerjacks are the first roof vents designed to meet the more stringent venting requirements of dryer exhaust systems.
Connect your dryer to its power sources and turn it on.
The warm moist air inside the vent tends to.
Check with your appliance dealer or local building inspector for recommendations about the best roof vent cap to use.
You can now replace the outer vent cover.
The problem with attics the attic is usually colder than the rest of the house during the winter and that can create a problem for a dryer vent.
Unlike the vents shown above left the dryerjack affects airflow by less than 01 water column inches of pressure.
Once you have done this turn off your dryer.