Originally Posted by
Warren Alderman
is it allowed to discharge a dryer vent onto the roof covering?
Yes.
You are not really discharging in "onto" the roof covering, you are discharging it "into" the air above the roof covering.
It is done quite often and they make special dryer exhaust vent roof cap flashings for that. No screen, has a damper, and there is a neck down inside below the roof sheathing over which the dryer exhaust slips and is connected and sealed to.