I am trying to determine if there is a vent pipe for a washing machine install on our second floor. We have expereinced a major leak on the floor and the ceiling below when the washing machine is draining. I am wondering if there is a vent pipe, which would be behind a wall, and if there could be a blockage in the drain forcing the water to over flow through the vent pipe.

Do you have a diagram of a typical vent pipe for a washing machine installed on a second floor?

revtbk

Hey Revtbk:

If drain was clogged then water would overflow the drain pipe before it would interfere with the vent (vent is above the drain)... so most likely vent has nothing to do with leak.. ok?

Here's a couple of pictures of sink and washing machine drains/vents.

Does water show on the floor by the washing machine? Have you checked behind the machine and at the water valve itself or the WM hoses? Also should check where the drain hose itself connects into the drain. Eliminate the obvious first and then if nothing you may need to open the ceiling to determine issue.

Let us know more...

MARK

Why is the vent split into 2 sections, I'm guessing that the main vent is for the basin and the 2nd vent is required for the washer. You can not share the main vent because adequate venting would not be available in case of simultaneous use of both fixtures? If my assumption is correct, it would be easier to just use a larger main vent to avoid the 2nd vent? Maybe a 3" instead of 1.5 " or 2"?
Thanks

Jwbrenna states, "You can not share the main vent because adequate venting would not be available in case of simultaneous use of of both fixtures?"

Generally speaking, that statement is correct, Jwbrenna... :)

Your assumption, however, is incorrect and does NOT follow venting requirements for a washing machine drain/vent and wet venting principles. Here, in some cases, you can actually increase the vent size as you presented (called wet venting fixture(s)), but in this case you have a washing machine and a laundry sink and you CANNOT wet vent any plumbing fixture using a washing machine drain/vent, OK? In this case, the sheer volume and velocity of water that gets discharged from a washing machine (especially the newer models) will overwhelm the system and if the washing machine drain/vent wet vents another fixture (in this case a laundry sink) it can siphon the trap of the laundry sink when the washing machine drains and that can allow sewer gases to enter the home... an absolute No-No in basics of plumbing!

Questions? Let me know... glad to discus more if you want!

Mark