Hello,

I have moved my washer and dryer and added a sink for a 1/2 bath in that spot. The washer had an existing trap in the wall. It would be a real pain to cut it out because it is galvanized pipe and because of were the trap is located.

Would it be OK to leave the existing trap in the wall and add another trap under the sink like normal? Would this have any effect on the draining of the sink? This will not need an inspection so I am not worried about code just function. Thanks!

"Would it be ok to leave the existing trap in the wall and add another trap under the sink like normal? Would this have any effect on the draining of the sink"

Out of the fact that Section 703.6 of the Standard Plumbing Code forbids double trapping of a fixture it just isn't good plumbing practice. You're just begging for blockages with two traps. Although I wouldn't recommend doing it unless you were thinking of doulble trapping the sink you could connect the sink drain to a drainage ell and arm over to the washer stand pipe and connect with another drainage ell. That way you will be using the washer trap and vent for your new sink. Good luck, Tom

You think it would be better to use the existing washer and dryer trap than have two? I could easily use the existing trap. Only problem is it would be buried in the wall and it doesn't come apart for clean-out.

What do you think? Maybe I just need to suffer and cut the old one out. Yikes... It's a real pain though... Thanks for the reply!

By the way, I am using the old washer and dryer drain line and vent. That's why the trap is in the wall...

If the washer stand pipe is on the outside wall then you could install a cleanout tee in it or install the CO tee just below the last drainage ellbo. Any configuration is better then a double trap. Regards, Tom

It is located on an outside wall so I will consider adding a clean-out like you suggested. I will not use a double trap.

Thanks for the help Tom!