need help fixing water valve to toilet tank
June 22, 2010 8:53 AM   Subscribe

need help replacing the valve which supplies water to my toilet tank. As usual, there are some minor (?) complications.

I need to put a valve on a pipe that doesn't have threads any more.

I had just finished replacing the floor in my bathroom and went to hook the toilet back up. I connected one end of the supply hose to the toilet tank and the other end to the valve on the water pipe, but the cheap plastic handle on the valve broke off when I tried to turn the water supply back on. After shutting off the water at another valve upstream, I went to remove the old valve and the water pipe snapped right at the base of the valve. There are no more threads on the water pipe; they are all in a big corroded mess inside the old valve.

I need some way to attach the new valve to the old pipe, either permanently on my own or temporarily until (sigh) I have to call a professional. Please assume "dangerous amateur"-level handyman skills on my part, and both a local hardware store and a big-box home improvement warehouse nearby for any tools or material.

thanks in advance!
posted by xbonesgt to Home & Garden (14 answers total)
 
I'm pretty sure a toilet stop valve uses a compression fitting on the supply side. When you go down to the hardware store, you will see how the fitting works.
posted by Thorzdad at 9:11 AM on June 22, 2010


Well, the correct way to do it would probably be to thread the end of the pipe ... but I don't think you can thread it in-place.

For a quick fix, you might be able to use a copper-to-PVC compression fitting. You'll need to cut the copper pipe clean and square, so hopefully there's enough of it left sticking out of the wall to install the compression fitting. Then you can use PVC to run up to the toilet. Might even be able to use flexible PVC or something.

I wouldn't expect that to hold for very long; the real solution is to replace the short piece of copper sticking out the wall that broke. My guess is that if it snapped going into the valve easily like that, the pipe is probably severely corroded. It's anyone's guess whether it will stand up to a compression fitting for very long.

I would keep the water shut off when you are not in the house, just in case it lets go when you're not around.
posted by Kadin2048 at 9:13 AM on June 22, 2010


Three approaches:

1) Attempt to use a galvanized pipe compression fitting. Ideally you want one with a threaded end to attach a valve or one with an integral valve. The likely problem with this solution is your pipe is rusted and might either fail again or collapse.

2) Unthread the broken pipe from whatever fitting it is screwed into and replace the pipe. Again because your current pipe is corroded it's likely that all the pipes along the line are corroded. You risk breaking off the pipe farther upstream.

3) Rethread your existing pipe. You can rent a manual pipe threader. You need enough space to swing about a 24" long tool through 15 degrees or so of motion. Again you risk breaking the pipe off further up stream. And there might not be enough thickness of pipe remaining uncorroded to be threaded.
posted by Mitheral at 9:24 AM on June 22, 2010


Measure the pipe diameter and go to your hardware store. Chat the guy up about what you're trying to do.

I've found it useful to shove a couple of pieces of white bread into the pipe to keep back any drips of water. Just be sure that the valve is OPEN when you are heating it and don't add so much solder that it gets into the works of the valve. In fact, buy a couple of valves in case you screw the first one up (just heat it again to remove it if you need to).
posted by bonobothegreat at 9:32 AM on June 22, 2010


Response by poster: Thanks, all.

I have about 4" of pipe sticking out of the wall. It looks like it's in decent shape and might be able to be re-threaded.

I also called up Big Box Store and the old guy I talked to said that based on the age of my house (1930s), I might be able to unscrew the visible pipe since it's only a 'nipple' which could maybe be replaced. Viable option?
posted by xbonesgt at 9:33 AM on June 22, 2010


If it was threaded, I'm sure it wasn't a copper pipe that snapped. It was probably galvanized iron pipe. My vote is for the galvanized pipe compression fitting Mitheral linked to. Don't use black galvanized pipe, it isn't suitable for water.
posted by Daddy-O at 9:35 AM on June 22, 2010


You have to be able to hold back with another pipe wrench whatever the broken nipple is screwed into when you unscrew it and screw in the new nipple. It's going to be difficult if that fitting is inside a wall. Don't forget the teflon tape!
posted by Daddy-O at 9:38 AM on June 22, 2010


What the big box store guy said is the "right" answer, but is likely to lead to more pain, if the threads on the other end of the nipple are also corroded and end up breaking off in the elbow that they're (likely) screwed into. (Trust me on this one - I just sold a house built in 1928 and ran into a lot of these same problems during 8 years of remodeling.) If you're set on doing it yourself, I would agree that Mitheral's galvanized pipe compression fitting is going to be the simplest solution, if you can find one at a store local to you. (I don't recall seeing them in the stores here, but I've never really looked, either.)
posted by jferg at 9:53 AM on June 22, 2010


xbonesgt writes "I might be able to unscrew the visible pipe since it's only a 'nipple' which could maybe be replaced. Viable option?"

That's option two. I'd use pipe dope rather than teflon tape, it works better.
posted by Mitheral at 9:55 AM on June 22, 2010


WAIT! If the threads were rotten on the end sticking out of the wall, then don't go trying to remove the pipe because it's likely that the threads on the other end are nearly as corroded. Be very gentle and don't wiggle it any more than you have to.
posted by bonobothegreat at 9:58 AM on June 22, 2010


Best answer: Don't waste time or resources. While I look at any problem as an excuse to buy a new tool, sometimes you have to admit that you are in over your head. You do not want to be breaking off the pipe inside the wall. Inevitably, you are going to call in the pro. Do so while there is still 4 inches of pipe sticking out of the wall.

Mitheral's compression fitting idea is nice, but the one in his example is for 1 inch pipe. Unless this is a commercial factory bathroom, yours is likely 1/2 inch pipe. I have never seen one for this size pipe, although that does not mean they don't exist. I'm pretty sure Mr. Big Box doesn't stock one. How long do you want to go without a toilet while you watch for the UPS guy to show up?

Time to get the guy with the tool belt to size up the situation.
posted by Old Geezer at 10:39 AM on June 22, 2010 [1 favorite]


Compression fitting. I just did this and they have some pretty nifty new ones that just slide right on there, nothing else required, not even tightening it. All sizes too. Cost you $10 and take 4 seconds. The new ones even come off if you need them to.

Never put a hole on your wall unless you absolutely have to!
posted by fshgrl at 1:23 PM on June 22, 2010


I think you are talking about sharkbites fshgrl; they don't make a version for galvanized pipe.

Old Geezer writes "Mitheral's compression fitting idea is nice, but the one in his example is for 1 inch pipe."

True. I wasn't saying get that fitting specifically; just one of that type. Honestly I don't know if I could buy one locally but we don't have much galvanized pipe here as we don't have much housing stock that old.
posted by Mitheral at 2:28 PM on June 22, 2010


Response by poster: the pipe is 1/2" OD, and (if Big Box Guy #2 is correct) is made out of brass, which is apparently pretty common for houses this age in this city. I don't think it's galvanized since it's sort of a coppery color, not the powdery steel gray of the galvanized fittings I saw at the store.

The product brochure for Sharkbites doesn't mention anything about connecting to existing brass pipe, so who knows how well the seal would hold up. I couldn't find anything else at the store that matched the diameter of the nipple, not without adding a lot of putty/washers/etc., which (as was pointed out to me) would probably come flying off anyway as soon as I turn the water back on and the pressure builds up around the seal.

Time to call in reinforcements.
posted by xbonesgt at 9:12 PM on June 22, 2010


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