Originally Posted by leefl
Sort of ... I'm not exactly sure where the vent pipe runs. I'm guessing it's in the corner cabinet in the bathroom ? I'll take a look next time I'm at the storage lot.
If so then I guess to seal the bottom you do it from inside the camper ?
Also sounds like there's an outer sheath around the pipe ? (is this what the vent cover you refer to is ? or do you just mean the cap ?)
I'll take a look maybe this weekend, if I get time to head over there.
Thanks for trying to clarify
Mine comes up in the wall next to the head.
I sealed it from the roof. I had the vent cover completely removed exposing the black pipe going through the roof. From that vantage point I was able to use the tube nozzle on the expansion foam to fill the opening around the pipe at the bottom of the ceiling duct and once cured was able to fill the gap at the roof level. I then replaced the vent cover and sealed it around the edges with Dicor.
Doing it that way stopped the A/C flow out the roof and down the wall to the top of the waste tanks.
I also used the foam to fill the "blunt" areas around the A/C unit and after curing used a knife cutting open a new channel to the ceiling ducts a more streamline design to encourage better air flow.
Both of those "repairs" increased my air flow by almost double, at least.