Am I to Fix The Broken Pipe Beneath the House?
April 14, 2010 9:39 AM   Subscribe

Am I to Fix The Broken Pipe Beneath the House?

This morning I woke up to weak water pressure on the hot water line, and the sound of running water from under the house. I turned off the water at the street and crawled into the crawlspace, then my wife turned the water back on. There are a set of pipes that run along the ground. Some are metal, some are PVC, and they are connected at various joints from previous repairs. I found two things:

1. I found the broken pipe. It was a metal pipe about 3 inches in diameter. It looks like it was rusted through at a point just before it reaches the 90 degree joint. I can feel with my finger the missing part.

2. I also found a lot of water on the ground, but it wasn't near the leak. The leak was about 6-7 feet away from where I found a couple of puddles of non-trivial water. When the water was on briefly, I didn't see what might have been causing those particular puddles.

Here's my question. I can fix pipes. I used to work for a construction company where I mainly had to plumb for installing swimming pools. But, I've only replaced PVC pipes. Metal pipes made me wonder if I was going to be hacking away at something forever. Is it too different?

I was also reading online and the advice was considerably foreboding. For instance, some said that needing to have a company come out with a thermal sensor to find the leak. I'm assuming that is because they don't see the leak immediately, whereas I at least see the main leak that is causing (I think) the water pressure to fall and the sound of rushing water. I do not see, though, where the puddles are coming from, but putting that aside for a second, I see the broken pipe. Still, the existence of puddles away from the pipe has given me pause over my hypothesis that this is just the single rusted piece of pipe that I see.

So questions are:

1. Should I replace this myself? I am comfortable repairing pvc pipes. Is this too different?

2. How much am I going to be dealing with using a plumber?

3. How long is this project on my own?

4. The other puddles.
posted by scunning to Home & Garden (19 answers total)
I would say that you could give it a try, if you can figure out how to make a good metal-to-PVC joint. Then just replace the broken stuff with PVC. I would imagine that the broken pipe is galvanized.

If this does not work and you need to get a plumber, you'll be out a little bit of money and some time, and it COULD work.
posted by Danf at 9:44 AM on April 14, 2010

I'd call a plumber - I can also repair PVC plumbing, but have never done copper pipe soldering and would not be willing to teach myself on a real repair.
posted by jquinby at 9:45 AM on April 14, 2010


1. Sure, why not try? You probably won't do any more damage, even if you can't fix it. The big difference is the obvious one, you can't glue anything to the metal pipes.
2. No idea how much it would cost to have a pro do it.
3. Based on my own limited experience with these things - budget an entire day with 2 or 3 trips to the store. You may do better. Cutting the existing pipe might be a royal pain, depending on how much space you have to work in.
4. My best guess would be that the puddles are collecting at the lowest point, even if you can't tell that the crawlspace is sloped when you're under there.
posted by ecurtz at 9:53 AM on April 14, 2010 [1 favorite]

I worked for my father's plumbing company during university. I did mostly gasfitting, but I sometimes did plumbing. Working with copper pipe is not hard. Just get some advice at the local Home Depot and give it a try. The worst that could happen is that it does not work and you have to call a plumber.
posted by KokuRyu at 10:10 AM on April 14, 2010

Response by poster: The thing about this metal pipe is that it does not appear to be copper. IT appears to be old metal. But I'm assuming that what it looks like is irrelevant. Also, I could've sworn that there was pvc connected to the metal pipe at an earlier point. Can water not run through pvc pipe or something? Plus, this thing rusted, which means it's not galvanized steel right? (assuming that the article I just read about how galvanized steel cannot rust is correct).
posted by scunning at 10:15 AM on April 14, 2010

Good luck threading a 3-inch galvanized pipe. The threader alone is going to set you back a few hundred dollars. Maybe the pipe is copper and you lucked out, but everything you posted suggests galvanized.
posted by malp at 10:21 AM on April 14, 2010

NAPBOAOH (Not a plumber but own an old house) and I've never heard of a residential water supply 3" dia. It sounds more like a waste or vent pipe. Most houses have either a galvanized pipe (which should be replaced) that's about an inch thick or a 1/2" or 3/4" copper. Take another look near the puddles or turn the outside water back on and check.
posted by bonobothegreat at 10:21 AM on April 14, 2010

Response by poster: Sorry - I made a mistake. It's 3 inches in circumference, not diameter. I wrapped string around the pipe and measured it and it measured 3 inches.
posted by scunning at 10:23 AM on April 14, 2010

Side-remark: galvanized steel will rust, it just takes longer. The idea, generally, is to just make it take long enough that you'd be replacing the item anyway so then it doesn't matter.
posted by aramaic at 10:38 AM on April 14, 2010 [1 favorite]

Oh, it's probably 3/4-inch or 1-inch pipe. You could mail order a hand threader for $80 or rent one for $40 give or take, but you should replace all the galvanized pipe with copper or pex or cpvc. Galvanized pipe clogs or rusts out. You may end up snapping the pipe when you try to thread it.
posted by malp at 10:41 AM on April 14, 2010 [1 favorite]

My instinct with non-welded galvanized piping would be to unscrew it at the joints and replace whole sections with matching lengths, not cut the pipe. In a crawl space, unscrewing rusty threaded joints may not be a fun job. You'd probably need a couple of big pipe wrenches and a lot of persuasion, and a crawl space may not let you get any leverage on the wrenches.

The other thing I'd be concerned about and make me call a plumber, especially given the mystery puddles: if your pipes are at the age where they are rusting through, and didn't just break from freezing or something like that, it's actually likely that you have other thin spots or tiny leaks, and the whole piping system needs replacing.

I believe my mom had her (metal) water piping all replaced a couple of years ago with PVC for the exact same scenario, but I could be misremembering that.
posted by ctmf at 10:46 AM on April 14, 2010 [3 favorites]

Yeah, take this opportunity to get all that galvanized water supply pipe out of your house. Fixing one small piece of it just kicks the can down the road a bit. PEX is great stuff. Given that your pipes are probably pretty corroded at this point, you may get a nice increase in water pressure.
posted by electroboy at 10:51 AM on April 14, 2010 [3 favorites]

Can water not run through pvc pipe or something?

PVC is safe up to 140 degrees. You probably want your hot water to be 120.
posted by Danf at 11:01 AM on April 14, 2010

Agreed that you should just replace the whole thing. I bet there is so much rust buildup inside that the water is coming through a pinhole. Easiest is to do Pex with Sharkbite connectors, but if you own the house, think of your long term game plan in regards to plumbing (for example, if you plan on all copper, start now with copper, just be careful of not burning your house down). I'm just a girl and I do all my own plumbing in my 105 year old house. Research your basics and you will be fine. I used to cut out the bad pipe, carry it down to my local hardware store, and they would tell me what to get and walk me through it. (they usually are not up do date on pex and newer connectors, though)

If you have a friend with plumbing experience to guide you a bit, that would be fabulous. Other than that, google for awhile...

You will feel very empowered.
posted by Vaike at 11:21 AM on April 14, 2010 [2 favorites]

Also, take your time turning the water back on, open all your faucets. The worst is when the force of the water pushes all the rusty stuff into a packed mass and you have to replace more plumbing right then and there (you will have to get rid of your galvinized eventually).
posted by Vaike at 11:22 AM on April 14, 2010 [1 favorite]

1) According to the Stanley new-home-owner-learn-about-plumbing book I read, there is very little resemblance between plumbing with PVC and with steel -- the tools are process are entirely different. I'm not an expert, and you may be able to rent or borrow some of the tools required. (The book also said that it is a very bad idea to mix metals carelessly, because it causes corrosion. I don't recall if PVC + steel was a problem.)

2) The absolute best and only way to answer this question is to call plumbers and ask them to come and quote it for you. Most plumbers will not charge you to just look and quote, and plumbing prices vary wildly by location and just by plumber. My wife and I were recently quoted prices that varied by 250% for a fairly simple job.

3) Plan for at least an entire day, ideally an entire weekend or three-day weekend. As others have said, expect to go to a supply place at least three times.

4) Sadly, the only sure way to determine whether those other puddles are related is to fix the leak you found. You know you have to fix it anyway, so fix what you've identified as broken and then see if there are still other puddles.
posted by contrarian at 11:42 AM on April 14, 2010

Response by poster: Thanks everyone. Just got back up from the crawlspace where I tried to get the metal pipe loosened at the joints. Couldn't get it to budge at all, and it ended up tearing the pipe at a place somewhere else, attached to a different joint, that I didn't notice. Turns out that part was even more corroded than the part I was working on. So I pulled it off. If I could just get the corroded elbow off the healthy pipe, I could work with this PEX stuff I read about, but I can't get that thing to move at all. And as there's a corroded piece in the threading, I figure I'm going to have to get a plumber out here.
posted by scunning at 11:58 AM on April 14, 2010

You can cut off the galvanized pipe as far up the run as possible and connect it to pvc w/ a special coupling. Try and replace as much of the galvanized as possible.

Do you have a good hardware store nearby? Hopefully, because whatever tactic you take, it'll take a minimum of three trips to the store to complete the job.

Here's a discussion on TOH forum showing a hub type of coupling. Here's a resource for the coupling. Here's another discussion on the mechanics of how to do this connection.
posted by mightshould at 12:33 PM on April 14, 2010

Response by poster: Thanks everyone for their help. I ended up capping the line and on Saturday am going to attempt to replace it with PEX. It'll be a good exercise and I look forward to it. Thanks again. EXTREMELY helpful comments.
posted by scunning at 3:06 PM on April 15, 2010

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