Re-Occuring Lavatory Blockage

I'm having a recurring problem with a galvanized lav drain...

About a year ago my upstairs lavatory drain was draining slowly. I borrowed a friends manual 25' snake and with some patience I was able to clear it. I could run the water full blast with no backing up. But slowly over time the problem came back. It would back up into the lav, but within 15-20 seconds the lav was empty. Not really a big deal.

My roomate asked if he should plunge it... I said DO NOT plunge the sink. I left for Thanksgiving to visit some family, and when I got back he said he plunged the hell out of the sink and now it's totally clogged. It does not drain... water stayed for hours until I removed the p-trap.

I called a plumber and he worked on the drain for a half hour or so. He said even with the smallest bit (1/4") he couldn't get through a 90 in the wall... about 8' in. He said "This is some old stuff" and the galvanized is probably rusting (or rusted) shut. Apparently the drain stub takes a 90 right then takes another 90 left to a vertical piece of cast iron. The problem is at the second 90.

Any suggestions or insight? Did my roomate plunging form a huge slug?

I'm going to try my manual snake again this evening after work... I remember it took me a while to get through the clog last time.

The plumber may very well be correct. Unfortunately, galvanized pipe does fail due to rust. I don't hold much hope for your manual snake, but you have it, so go ahead and try. It may be you will need to consider a new drain line. That's not a very happy thought, and isn't recommended as a DIY project. It will take a plumbing contractor on site to really evaluate what your total problem is and what it will take to fix it.

If there are any galvanized 90's in that piping, those close up quicker than the pipe itself.

The absolute worst thing that can be done to an older galvanized drain system is to stop using it.

It'll dry up the contents inside and a drain cable will pass through without removing the buildup.

Galvanized drain piping would hold up a significant time longer if people did periodic maintenance to the drain, clearing the piping every so many months.

Reality is it does not get cleaned for years/decades till it clogs, and the aftermath results in chronic plumbing issues from there on out.


I have one customer that has just that, and I'm going to give that job away to a local plumber where he lives when it comes time to rip it all out.

Too extensive and it is going to destroy a kitchen and bathroom both when it has to be replaced in the walls. Horrible.

Thanks for the replies. I always appreciate the insight. I have a little more information after working on the line yesterday evening. I attached an isomertric of my drain.

A few notes:
1. The 2" cast iron to the left of dotted line is running vertical up the side of my house. This pipe is converted to 2" PVC and continues under my house.
2. There are 3 90s in the wall before the 90 I can see outside.
3. Somewhere in the wall the drain turns into cast iron. The drain seemed clean until I hit the clog... Perhaps only the stub is galvanized?

I was able to get my 25' hand snake about 18' into the line, so the clog is definitely not where I originally suspected. When I pulled the snake out the end was caked with thick mud/sludge/etc. It was obviously difficult for me to twist a hand snake that was 15'+ down the line, so I know I didn't clear it. I don't think the plumber got this far down the line. He said he couldn't navigate past the 2nd 90.

I then decided to remove the no hub outside and run the snake up the vertical CI outside. I didn't get much past the 90 and I couldn't go any more. The snake end was full of hair/gunt/sludge/etc so I think I hit the clog. Can a motorized snake be run up a drain, or is that dangerous? Should I call the plumber back and have him snake from outside?

So I think the good news is that it's not a problem with the galvanized... because replacing the horizontal section between the floors (where the clog is) would require removing the ceiling in my dining room.

If you got your snake into the pipe 18 feet, but the plumber could only go EIGHT feet, then you probably need a better plumber, with a better snake, unless your snake is so pitiful as to be ineffective.

That is a valid point, too. I used a reputable company, and one I've used in the past... however, they sent out a different guy this time.

I reconnected the drain last night and poured in water until the point it backed up into the lav again... and NOTHING came out the vertical cast iron outside. So it's 100% clogged.

I'll call someone else...

hj said:

... then you probably need a better plumber ...

Click to expand...

Wise words!

I called another plumber. He said the clog/rust was at the last 90 outside and ran his snake through several times and cleared it without a problem. He reconnected the lavatory, filled the bowl 4 times to flush out any remaining loose debris. The water drained right out. Cost me $150. Satisfied customer. He guaranteed his work for 30 days.

hj said:

If you got your snake into the pipe 18 feet, but the plumber could only go EIGHT feet, then you probably need a better plumber, with a better snake, unless your snake is so pitiful as to be ineffective.

Click to expand...

That's not exactly true.


If a plumber goes in with a drain cable to the largest size diameter head possible and cannot maneuver through 90's,

one has to believe that the plumber or drain cleaner is trying to effectively clean the drain to the best of his ability.


We all know that a 1/4" cable can manuever through a line that's closing up, but has no brute force to do any significant "cleaning" along the way.


All the property knows is the drain is flowing fine, wants that to stay that way longer than the last backup.

If I've already ran the best cable down the drain and cannot get it open, it's a judgement call back to the homeowner if he wants to spend the extra money with more than one cable.


If the plumber used the same exact sized cable as the property owner, plan 3.

I would have preferred do be home for both plumbing appointments, but my schedule didn't allow it so I had someone let the plumbers in and wait till the work was done. So all my details are second hand. I only spoke with the plumbers on the phone.

Having said that, my "sitter" made a comment that the plumber today used a "big heavy round machine snake" He said the first plumber had some sort of drill operated snake. So they didn't use the same machine, that's for sure. So perhaps in this case it was the plumber. And the guy told me over the phone I won't have any problems with this drain for a long time. I sure hope he is correct.

I received a bill last week from the first company that was unable to clear the drain. What would you suggest in a case like this? They sent someone out and charged me for an hour of labor, even though the plumber (in my opinion) didn't know what he was doing. He told me the drain was totally blocked and I needed to rip down the ceiling on the 1st floor and replace the entire drain.

A different plumber came the next day and cleared the line in 30 minutes.

Would anyone recommend calling the first company and let know that the line was fine and the replacement they suggested was totally unecessary? Or should I just pay and not call them back?