Recently discovered that my dryer has been venting into my subfloor with no outside ventilation. To fix this im having to run the vent hose up to the attic then to an external wall (long story but is required). Due to the extra length to the hose and the subsequent lent fire hazard i am thinking of adding a second lent trap in the vent line on the wall behind the dryer. It would be easily accessed and cleaned out after every load. Would anyone have any good suggestions on how to do this or dos and donts... any help is appreciated.