Our washer has been leaking water over the lip of the standpipe. When I push a clothes hanger into it (trying to dislodge possible blockage) it only goes about 10" and then hits plastic.

Is it possible the original home-owner installed the P-trap without a standpipe? He was a bit of a handyman but we've noticed some of his handywork is a bit shoddy. If so, what options do I have short of rip and replace the plumbing?

Is there any other explanation why we might be hitting plastic 10" from the lip of the standpipe where it connects to the U-shaped end of the washer's drain hose?

Thanks,

--
Bruce

More details please. How far off the floor is the trap? If the pipe coming out of the trap is only 10 inches long then it needs to be lengthened.
Is there any other explanation why we might be hitting plastic 10" from the lip of the standpipe where it connects to the U-shaped end of the washer's drain hose? Yes. You're hitting the base of the trap.

If you will tell me how far the trap is from the floor and the pipe size I'll tell you how long you must cut the extension. Back to you. Tom

Thanks Tom. The P-trap (if that's what I'm hitting) is 4 feet off the floor, with the lip of the standpipe at about 5 feet next to the hot/cold water hoses in the recessed outlet box. Also, the standpipe can be lifted out of the trap easily, like it was just set into place without glue or tightening and it's about 8" long.

There are cabinets about 8" above that recessed box.

At this point, I'm thinking we just need a plumber to take off the drywall and install a longer standpipe. But I'm just checking if there might be a simpler fix I'm missing?

I'm thinking we just need a plumber to take off the drywall and install a longer standpipe. But I'm just checking if there might be a simpler fix I'm missing?
AS a rule I'd recommend lowering the trap and doing the job in the correct fashion but you have a washer box recessed behind drywall. That would be major surgery to redo. Sooo,
I have a much simpler solution. Make the connection between the standpipe and the washer hose a hard connection.
First, prime and glue the stand pipe in the trap. You may now do one of two things.
1. Purchase a compression type fitting,(see image) in the correct size and glue that to the standpipe. The hose will compress in the fitting making a waterproof connection. **OR**
2. You can do what I did was when I was faced with the same problem. I Duct Taped the hose to the stand pipe with the same results. That was over 5 years ago and still no backups. Let me know how you make out. Good luck, Tom

Thank you Tom. That's super-helpful.

Do you know if there are building codes I need to check into first if I make it a hard connection? Or would this not be covered by building codes?

Not to worry! You won't be breaking code. But even if you were, If you don't tell. I won't tell. Good luck, Tom