1 1/2" drain pipe - ok to be shared among kitchen sink + laundry sink?

[joecm3]

Hi,

I have an existing 1 1/2" galvanized drain pipe servicing the kitchen sink.

I want to add a wall mount laundry sink in the garage that is behind the kitchen wall, so it would be sharing this 1 1/2" galvanized drain pipe.

Is 1 1/2" galvanized drain pipe good enough to serve both sinks, or I need to change the drain pipe to 2" size?


Also,

I just wonder if it's a good practice to put the wall mount laundry sink that's behind the kitchen wall (I'd need to do something for the whole wall area behind the sink to prevent dry wall damage if there's spill from the laundry sink?). Another location would be next to the washer machine in the other corner on the side wall of the garage, although space is tight there.


Thanks.

 

[frodo]

nope, you need 2'' can you post a picture of where the 1 1/2'' ties into the other pipe

 

[joecm3]

The bottom of the 1 1/2" galvanize pipe for the existing kitchen sink seems to be a threaded end but it goes go a CI hub (old house so it's CI main pipe). Not sure if it's in fact joined w/ lead to the hub.

Attached photo:





So the P-trap and the trap arm for the laundry sink needs to be both 2" diameter?