you must insulate the vent pipe with the sock insulation. this will eliminate the condensation from the cold attic, that will build up in the pipe or drip back down 10 minutes later after shower.
and use solid ducting in order to not have low spots that will alow water to sit in. slope pipe to outside wall if you can or put it straight up through roof with a proper roof vent that has a flapper .
Remember the past or all is lost. http://www.geocities.com/theeagles_page/
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