Water leaking behind wall

[Gordo]

I have a unique situation where I have 2 bathroom tubs (both with moen diverters) that each seem to be leaking behind the wall through basement ceiling at the same spot. The tubs are several feet apart. Have tested each by: 1 filling tubs from spout and then draining with no leaks; 2 running hot and then cold water from spouts with no leaks; 3 running showers cold with no leaks; 4 running hot water from showers and get leaks from each but leaks only directly below one of the tubs.
Is there any way the cartidge in the faucet above the leak could cause both hot showers to leak.
Have taken off handle and plate to view diverter but dont see evidence of water leakage at pipe connections.
Am at my wits end trying to figure this out.

 

[Chucky_ott]

**edit** I re-read your post on my computer this time and it looks like you do have a leak. So disregard my initial answer

You have observed an actual leak with water or are your just hearing a water drip? if the former, I can't help. if the latter, it could be just the pipes contracting as they cool. It does that in my house after every hot water use. it sounds exactly like a water drip as the pipes contract and do a tick-tick sound when they rub against the wood joists.

 

[Sponsor]

 

[ImOld]

So, only turning on hot water causes water to leak in the ceiling. Cold has no effect.

Can we assume the install is back to back in the same wall?

You have turned on one shower, observed a leak and waited an hour or two before trying the other. Is this correct? If not, the leak could just be residual from the first shower.

It is certainly possible for multiple leaks in the same wall to show up at the same spot. Very common in my experience.

Pretty hard to believe one diverter is influencing the other as far as leaking.

Has this problem just shown up out of the blue or has work been done in the bathrooms recently?

 

[Mliu]

How long has this leak been running? If it's been a while, you surely have much bigger problems now. If it's something that just started, you need to get it fixed fast before you get mold, wood, rot, termites, etc. It's important not to let the water stay trapped between the walls and between the floor and ceiling. If you have some plain drywall near the leak, I'd strongly advise opening it up and getting a blower (like the one below) to force air into the walls. You need to get air circulating in there quickly to dry out any moisture. drywall repairs are easy and cheap. Tearing out entire walls and floors gets very expensive.

A blower like this costs ~$100 at Home Depot. You need something like this in order to get enough air volume to dry the area.

 

[Gordo]

So, only turning on hot water causes water to leak in the ceiling. Cold has no effect.

Can we assume the install is back to back in the same wall?

You have turned on one shower, observed a leak and waited an hour or two before trying the other. Is this correct? If not, the leak could just be residual from the first shower.

It is certainly possible for multiple leaks in the same wall to show up at the same spot. Very common in my experience.

Pretty hard to believe one diverter is influencing the other as far as leaking.

Has this problem just shown up out of the blue or has work been done in the bathrooms recently?

The walls are not back to back - one is at least 4 feet away from the other.
While I've not run the water for an hour at least with the shower testing started with cold in both ran for good 5 minutes ( long enough to have seen leaking in past) and then hot on both when shows leaking on both. And yes did wait between tests for the first to have stopped dripping. When started 2nd began re-leaking right away.
Like you find it hard to believe the connection.
Will take off handles and cover plates and see if any leaks visible at cartridges. Thinking maybe spout diverter leaking water back though that wouldn't explain why only on hot side nor why hot shower on one would cause leak at other.
Regardless of what see will replace both cartidges and reseal behind spouts and see.
Will let you know results. Is a strange one.
Oh and no there's not been any plumbing work recently both baths I think were remodeled about 12 years ago.

 

[Gordo]

How long has this leak been running? If it's been a while, you surely have much bigger problems now. If it's something that just started, you need to get it fixed fast before you get mold, wood, rot, termites, etc. It's important not to let the water stay trapped between the walls and between the floor and ceiling. If you have some plain drywall near the leak, I'd strongly advise opening it up and getting a blower (like the one below) to force air into the walls. You need to get air circulating in there quickly to dry out any moisture. drywall repairs are easy and cheap. Tearing out entire walls and floors gets very expensive.

A blower like this costs ~$100 at Home Depot. You need something like this in order to get enough air volume to dry the area.

Thanks for the advice though I'm nit too concerned about mold or rot as only leaks a bit during showers usually only once per day and particlarly in winter here we've a very dry climate. Certdinly no termites this part of the world. Once find solution will have to remove and replace affected ceiling

 

[Gordo]

The walls are not back to back - one is at least 4 feet away from the other.
While I've not run the water for an hour at least with the shower testing started with cold in both ran for good 5 minutes ( long enough to have seen leaking in past) and then hot on both when shows leaking on both. And yes did wait between tests for the first to have stopped dripping. When started 2nd began re-leaking right away.
Like you find it hard to believe the connection.
Will take off handles and cover plates and see if any leaks visible at cartridges. Thinking maybe spout diverter leaking water back though that wouldn't explain why only on hot side nor why hot shower on one would cause leak at other.
Regardless of what see will replace both cartidges and reseal behind spouts and see.
Will let you know results. Is a strange one.
Oh and no there's not been any plumbing work recently both baths I think were remodeled about 12 years ago.

So turns out there are 2 problems - one of the tubs was leaking at the showers arm connecting behind the wall. Had re threaded it but guess wasn't tight enuf. Not sure why was only when hot but in any case fixed that problem. Second one turned out to be leaking drain pipe connection just about the basement ceiling where was showing leaks - again not sure why only when running hot water.
Concern with the drain pipe leak is that its at the downstream joint of a T connection coming down vertically from the tubs in the floor above. While normally would cut it out and replace it, can't access it to cut out. Have been doing bit research online and some suggest heating the joint (until uncomfortable to touch) and then adding more abs cement that claims will suck into the joint. Some also suggest using shop vac to put some negative pressure in the line to help suck cement into the joint. Also came across Leak B Gone but have seem less than great results. Along that line am thinking could cut a joint connector in half so as to remove the interior half way line and use that with abs cement pressed against the joint. Maybe both?
Thoughts?

 

[Mliu]

Heat causes materials to expand. That explains why the hot water can cause a leak while cold water does not.

As for "sucking" ABS cement into a bad joint, I say no way. First, you must realize that when plastic pipes are joined, they are NOT glued together. The correct term is "solvent welding" and what you are doing is chemically melting the surface of the plastic pipe and fitting socket. When you press the pipe into the socket, the chemically-melted plastic on the outer surface of the pipe fuses with the chemically-melted plastic on the inner surface of the fitting. The plastic from both parts bond together and form a weld between the two parts.

There is no way you can create a solvent weld by trying to wick or "suck" cement into a leaking joint. Pipe cement is very viscous and will not wick. Even if you could seal the pipe on both sides of the joint and put a high vacuum on the inside (I'm talking about a vacuum pump, not a shop vac), even that won't draw much cement into the failed joint. Plus, it will not solvent welt the pipe to the fitting, because that requires phycical movement between the two parts during the solvent welding process.

You may be able to stop the leak by applying cement to the joint seam because the cement does have some dissolved plastic mixed in and that may form a "cap" or "dam" on the leak site. But it will only be a temporary repair: as the pipe expands and contracts over time, that cap/dam will separate from the pipe.

The only real guaranteed solution is to remove the failed fitting and install a new one.

 

[Gordo]

Heat causes materials to expand. That explains why the hot water can cause a leak while cold water does not.

As for "sucking" ABS cement into a bad joint, I say no way. First, you must realize that when plastic pipes are joined, they are NOT glued together. The correct term is "solvent welding" and what you are doing is chemically melting the surface of the plastic pipe and fitting socket. When you press the pipe into the socket, the chemically-melted plastic on the outer surface of the pipe fuses with the chemically-melted plastic on the inner surface of the fitting. The plastic from both parts bond together and form a weld between the two parts.

There is no way you can create a solvent weld by trying to wick or "suck" cement into a leaking joint. Pipe cement is very viscous and will not wick. Even if you could seal the pipe on both sides of the joint and put a high vacuum on the inside (I'm talking about a vacuum pump, not a shop vac), even that won't draw much cement into the failed joint. Plus, it will not solvent welt the pipe to the fitting, because that requires phycical movement between the two parts during the solvent welding process.

You may be able to stop the leak by applying cement to the joint seam because the cement does have some dissolved plastic mixed in and that may form a "cap" or "dam" on the leak site. But it will only be a temporary repair: as the pipe expands and contracts over time, that cap/dam will separate from the pipe.

The only real guaranteed solution is to remove the failed fitting and install a new one.

Thanks so much for the advise and same conclusion finally came to as well.
Am now thinking if cut off the bell of the joint could I simply put on a 2 in flexible connection? Or would it be possible to slip on an ABS coupler? There are some striations to the right of the bell that would have to shave off.
Again thoughts?

 

[Gordo]

Heat causes materials to expand. That explains why the hot water can cause a leak while cold water does not.

As for "sucking" ABS cement into a bad joint, I say no way. First, you must realize that when plastic pipes are joined, they are NOT glued together. The correct term is "solvent welding" and what you are doing is chemically melting the surface of the plastic pipe and fitting socket. When you press the pipe into the socket, the chemically-melted plastic on the outer surface of the pipe fuses with the chemically-melted plastic on the inner surface of the fitting. The plastic from both parts bond together and form a weld between the two parts.

There is no way you can create a solvent weld by trying to wick or "suck" cement into a leaking joint. Pipe cement is very viscous and will not wick. Even if you could seal the pipe on both sides of the joint and put a high vacuum on the inside (I'm talking about a vacuum pump, not a shop vac), even that won't draw much cement into the failed joint. Plus, it will not solvent welt the pipe to the fitting, because that requires phycical movement between the two parts during the solvent welding process.

You may be able to stop the leak by applying cement to the joint seam because the cement does have some dissolved plastic mixed in and that may form a "cap" or "dam" on the leak site. But it will only be a temporary repair: as the pipe expands and contracts over time, that cap/dam will separate from the pipe.

The only real guaranteed solution is to remove the failed fitting and install a new one.

Thanks so much for that advise and finally came to the same conclusion about the hot water affect. Am now thinking maybe could cut off the bell and either put on a 2" flexible rubber coupling or even weld on an abs coupling splice - though in that case would have to shave off some striations on the Y pipe upstream of the bell.
Again thoughts?

 

[Mliu]

Thanks so much for that advise and finally came to the same conclusion about the hot water affect. Am now thinking maybe could cut off the bell and either put on a 2" flexible rubber coupling or even weld on an abs coupling splice - though in that case would have to shave off some striations on the Y pipe upstream of the bell.
Again thoughts?

You are using terms that are not industry standard, so it's difficult to understand what you're describing.

• Bell
• Coupling splice
• Striations
• Y pipe

Bell could be the hub of a fitting. Coupling splice could be a standard hub x hub coupling. Y pipe could be a wye fitting, but it also might be a sanitary tee. Striations???

We can't give correct advice based on our assumptions of what you're trying to describe. A picture is worth a thousand words. A couple of pictures is worth even more. Show us what you're dealing with.

 

[Gordo]

You are using terms that are not industry standard, so it's difficult to understand what you're describing.

• Bell
• Coupling splice
• Striations
• Y pipe

Bell could be the hub of a fitting. Coupling splice could be a standard hub x hub coupling. Y pipe could be a wye fitting, but it also might be a sanitary tee. Striations???

We can't give correct advice based on our assumptions of what you're trying to describe. A picture is worth a thousand words. A couple of pictures is worth even more. Show us what you're dealing with.

Apologize for the terms I've been using.
Bell I use to describe the female end of the coupling
Splice would be simple coupling
Striations term I used for the lines on the side of the fitting
Y pipe should actually be the T fitting that connects the vertical drain line to the horizontal
Hope attached photo will better explain