My sewer pipe is rotted and a vent pipe broke off... how do I find the end of the vent and what is reason for them?

Typically the vent goes through the roof of the house from the interior sewer lines. Vents admit and release air to allow the water to flow out. If water was flowing out a non vented pipe, negative pressure would keep the water back. Put a straw in a glass of water. Put your finger on the top and lift the straw. The water stays in the straw. Now, take your finger off. Water flows out and that is basically how a vent works.

Where are you and how old is the home?

Hello Ma0641,


Excellent explanation, Thanks.

John

Hello Ma0641,


Excellent explanation, Thanks.

John

Just kind of dreamed that explanation up. Thanks, Brian

Great explanation Brian!

My sewer pipe is rotted and a vent pipe broke off... how do I find the end of the ven This isn't a week end project for a home owner. This calls for a plumbing contractor. Get three estimates. Good luck, Tom

Tom is correct, especially if your drain and vent is cast iron.

Vents not only allow for proper drainage but also protect traps from siphoning which would allow sewer gas to enter the home. Sewer gas can be deadly so you need to get this resolved.