I have a Kenmore Gas Dryer, Model 26 70022 011, installed in our garage in 2012. Due to a remodel, I can no longer vent the dryer directly through an outside garage wall. Rather than run the vent through the garage to another outside wall (at least 30 feet), we'd like to go straight up and out the roof - about a 10-12 foot length. The installation instructions do not address venting through the roof, but they do have a Vent System Chart for rigid metal lengths. Is there any reason venting through the roof (no attic involved) would be a problem? I realize we will need a special type of rooftop dryer vent.