I am finishing a basement bathroom for which I have a rough-in, and will have to break into the concrete to move the tub drain a few inches because it was misplaced originally (Thanks for confirming that on my earlier post, speedball1). Since I will have to break into the concrete anyway, I was thinking I might be able to take the opportunity to install a bar sink on the other side of the bathroom wall and connect it to the drain pipe downstream of the tub drain trap. Since I noticed that another person's posting indicated that hooking up a clothes washer in a similar way would be a bad idea, I was wondering if that meant my idea was bad as well. If it isn't a bad idea, what are suggestions on how I should vent the bar sink? There is a stack near the toilet rough-in on the other side of the bathroom which may or might not work if a wet vent is a no-go.

Thanks,
Todd

Hi Todd, Welcome back.

" I was thinking I might be able to take the opportunity to install a bar sink on the other side of the bathroom wall and connect it to the drain pipe downstream of the tub drain trap. Since I noticed that another person's posting indicated that hooking up a clothes washer in a similar way would be a bad idea, I was wondering if that meant my idea was bad as well."

Not a bad idea at all. There's a lot of difference to draining a bar sink and discharging a washer. You may connect the bar sink to the tub drain with no bad results. You probably won't be able to vent back to the stack since it's a main drain and not a vent. However if local codes allow you can install a AAV( Air admittance vent) cheater vent,(see image). Good luck, Tom