Unknown vent pipe

I found this vent pipe in the attic, anyone know what it is for ???


What size is it? it could be almost anything fresh air for the furnace perhaps or a vent pipe that was not taken to the outside.

1 1/4 to 1 1/2 inches. It could be a vent for the central vac system. There were no ordors.

was it gray below the pvc? and was there central vac outlets?

My guess…central vac. Did you have or turn the central vac “ON”?

What’s that stringy crap coming out of it?

It looked like a shoe string.

Maybe they were attempting to snake wire/cable?

What rooms were directly below?


Periscope to check for rodents.

Brian, wins LOL

I see this in new homes, and have one in mine. It probably is a pipe that runs from the basement to the attic; in case you need to run future wiring. You may see the other end in the basement. It should be straight. It could be also pre-wiring for a security system/siren in the attic.