what kind of pipe r u using, i used pvc pipes on mine, and cleaned it real good around the pipe and inside, and then used some silicone inside, and then around the trim to prevent it from leaking. left it to dry for a good 48 hours and that did the job...then got kind of lazy and bought some cement glue at lowe's and glued it together "i know it was not right thing to do but just used small amounts and silicone on the outside.