New shower pan and shower drain installed a couple years ago. Shower drains fine.. washing machine less than 3 feet away starts backing up in shower. Does not overflow from standpipe. Standpipe is 18" high , 1 1/2 " inside diam.
Galvanized. I'm thinking to cut standpipe near bottom and install 2" abs with no hub coupler and make it obviously higher. Also snake laundry line and most likely kitchen line . This is a very old house,. kitchen and room with washer and shower stall only
Are on cement slab. Plumbing co. installed shower pan.and new line to the tune of over 3000.00 , I will check under house this week, (next day off) to see exactly what was done , I am almost posi tive the only abs is shower line. I just saw this house yesterday. Very sweet 84 year old new client and friend with very limited funds. Who lives alone.
I know this whole situation is not even close to code. I just want to help her out I did home repair work and quite a bit of plumbing for the past 10 years. I am now a manager with a well known non profit organization, which is where I met this very sweet lady. Does any one have any other suggestions? Thank you

Hi Tammy,

washing machine less than 3 feet away starts backing up in shower. does not overflow from standpipe. Standpipe is 18" high , 1 1/2 " inside diam.galvanized. I'm thinking to cut standpipe near bottom and install 2" abs with no hub coupler and make it obviously higher If it doesn't over flow there's no advantage to increasing the height of the stand pipe.
Has the washer always backed up in the shower or did this just start? I need a answer to this. If it backed up in the shower from day one then it's a design flaw and there's not much you can do. However, if this is a new problem this indicates a partial blockage downstream from the shower that can be snaked and cleared. Let me know, Tom

Hi Tammy,
If it doesn't over flow there's no advantage to increasing the height of the stand pipe.
Has the washer always backed up in the shower or did this just start? I need a answer to this. If it backed up in the shower from day one then it's a design flaw and there's not much you can do. However, if this is a new problem this indicates a partial blockage downstream from the shower that can be snaked and cleared. Let me know, Tom

Thank you for your quick response. The drain hose is pretty tight in the stand pipe, I will call her in the morning to answer your question, I don't think her kitchen sink ever backs up. Her shower by itself doesn't back up either I don't think. Does this matter

Tammy,
I don't think her kitchen sink ever backs up. Her shower by itself doesn't back up either I don't think. Does this matter
This is not what I asked. I asked; "Has the washer always backed up in the shower or did this just start?"
I need to know! Regards, Tom

You have blockage in the drain. Clean the drain and you will be fine.

That stand pipe shoud be 30" from the trap. But still, installing taller stand pipe will not solve your present problem.