The less back pressure is created by the roof vent the more efficiently the system performs.
How do you vent a dryer through the roof.
The vent should exit the building through the roof or wall at least 3 feet away from any other building openings and the vent cover which must not include a screen should allow dispersal of.
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.
If you re having a home built try to have your builder terminate the dryer duct at a location that makes sense.
Check with your appliance dealer or local building inspector for recommendations about the best roof vent cap to use.
Cleaning lint buildup from roof vents is difficult and nesting birds and squirrels often find roof vent caps irresistible.
Before you clean a dryer vent on the roof vacuum out the vent behind the dryer since it s easier to clean out the length of the vent from the ground floor.
A vertical dryer vent is typically a problem because it acts as a moisture condenser.
Once the vent is exposed use a vent brush first clean the exterior surfaces.
When bath fans and clothes dryers vent through the roof they melt a bunch of snow.
Difficulty cleaning dryer vent.
The sheet metal duct is cooled by the outside air in the attic.
But we don t recommend it for two reasons.
After the snow melts below the vent it ll probably freeze again farther down on the roof.
In my humble opinion dryer vent terminals should be accessible from the ground if you already have a home with a dryer that terminates at the roof be sure to have the terminal cleaned on a regular basis and consider having the terminal replaced with a dryerjack terminal.
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.
Dryer vents should always be vented through the side of the house and not vented through the roof and ideally the exit should be fairly close to the ground.
Vent a dryer through the roof only as a last resort.
Keeping a clean dryer vent is much easier when you can safely reach the exit.