Loose sewer vent pipe to roof vent

[myredracer]

Is the ABS black tank vent pipe supposed to be glued to the roof vent (ABS glue)? I just found ours wasn't glued and it only had a tiny dab of silicone on it. Maybe it's not supposed to be glued to allow for vertical movement? I just found this after doing some cabinetry mods and am not sure if I should try to glue it in. Would be hard to do though as the joint is buried up in the attic space and not accessible.

[dougrainer]

Old-Biscuit wrote:
NO the roof vent caps need to be removable just in case you need to run a hose down vent line to clear a blockage, replace vent cap due to damage or age.

The vent line should be secured to trailer wall/studs etc. so that the vent line doesn't move.........loose vent line can drop down into tank and become blocked off.

Very few Vent pipes are installed in a rubber slip gasket on top the Tanks. MOST are glued to the top of the tank. So, dropping into the tank is extremely rare even on the ones with a rubber slip gasket. Most vent lines are NOT a straight pipe from top of tank to the roof. They usually have a "Y" or a sink drain pipe connected to them somewhere in the wall. That also keeps the pipe from slipping down IF it has a rubber slip fitting. Doug

[Old-Biscuit]

Depends on style of cap........

Some have tabs, some have spring steel, some snap on, some use a single screw, some you have to remove complete assembly from roof etc.

[myredracer]

Thanks! Does the vent cap just unscrew so I can check inside it?

[Old-Biscuit]

NO the roof vent caps need to be removable just in case you need to run a hose down vent line to clear a blockage, replace vent cap due to damage or age.

The vent line should be secured to trailer wall/studs etc. so that the vent line doesn't move.........loose vent line can drop down into tank and become blocked off.

[dougrainer]

It is not glued, but should extend beyond the round slip of the Vent cap assbly. That ensures sewer gases do not have the chance to migrate backward inside the hole thru the roof cavity. The end of the ABS pipe should NOT touch the top vent cap cover to allow the gases to escape. Doug