Snapping to a waste stack

[james23]

Currently the branch drain that connects to the waste stack of my apartment building is 2". I need to replace this with a 3" branch drain for my washer machine. What is the risk of snapping a 3" branch drain to the waste stack of my apartment building in place of a 2" drain?

My plumber says its not a big deal but my building management thinks otherwise. any advise is appreciated!!

 

[johnjh2o]

Why would you need a 3" line for a clothes washer? 2" should be more then adequate.

John

 

[james23]

The neighbors sink is also connected to this drain, and im told we may have a back flow issue with the soap suds.

 

[johnjh2o]

If you have a new washer you may be using the wrong soap. Try cutting back on your detergent. Or the line may be partially stopped. 2" should be able to handle both your washer and a kitchen sink.

john