dryer pipe venting

Laundry dryer vent is venting to garage causing sheetrock to decay and lots of lint. I would like to vent up and out to the flat roof of the gagage with a 4 inch peice of PVC. Any tips on a type/where to get a quality roof seal for the PVC pipe which will be protruding from the roof so as not to have water leak. Any help appreciated.

Dave

Use an Oatey roof flashing that has the rubber boot made into it. There are plastic roof flashings and aluminum. I'd use aluminum ones.

You'll have to use either 2 90's as a turn down or a solvent weld trap in 3 or 4" whichever size you plan on using.

Take the vent pipe up at least 18" out of the roof, longer if steeper so lint doesn't start laying on the roof.

You are not allowed to use PVC for a dryer vent. It must be metal. Get solid galvanized single wall duct. Do NOT use any flexible stuff. It must be smooth wall. ( Only exception is up to 6 feet at the actual connection at the dryer can be flex)