I hear a drip in the wall?

My husband and I have been living in this house for the last 6 years and have never experienced anything like this before. We have two bathrooms but the one causing the problem has just a shower with tiled walls. For the last few days we've noticed a 'drip' (or at least what sounds like a drip) in the wall behind the shower (other side of the wall is our bedroom). It's just one drip at a time but not constant like drip-drip-drip-drip....I'll hear one 'drop', then maybe 20 seconds later I'll hear another 'drop', then maybe the next one will come 45 seconds later. We've also noticed that it's intermittant; in other words, it doesn't seem to be associated with shower use - there's times I'll hear it right after the shower has been used, other times I'll hear it a few hours after. There's no rhyme or reason to it. I also find it odd this 'drip' is loud enough that I can hear it even when I'm in other parts of the house. It's because of this that my husband doesn't think it's a drip at all, he says something dripping behind a wall would not be loud enough to be heard in another room. It seems rather loud to me too...it's almost similar to the clicking noise you can make with your tongue off the roof of your mouth, that's the only way I can describe it. If we stand in the shower and listen through the wall, we can hear it, or if we stand on the bedroom side and listen there, we can also hear it but can't pinpoint it.....we just know it's coming from inside the wall. Now my husband isn't a plumber and does not mind saying he knows nothing about plumbing, but he says it doesn't sound like a drip from water to him because he can't imagine what a water drip would be hitting inside of a wall that would cause it to be that loud. If it's not a drip, what else could it be and why would it start all of a sudden? And if it is a drip, how on earth do we find it and fix it?? The thought of ripping a hole in the wall isn't something we want to do, especially if it's not a water drip. We have no leaks of any kind inside the shower, or nothing obvious that suggests a water problem....just this constant sound of a drop of water hitting something. This wouldn't be the pipe, would it?Can anyone on here give us some idea of what this sound is? Or if it does seem like a water drip, is there a way we can fix it without going into the wall?
Any help or suggestions at all will be greatly appreciated.

Random thoughts

Seems to me that if it were a water leak, you'd see some signs of it by now, either at the bottom of the wall in your bedroom, or on the ceiling below. (Hmmm. What is below?)

One thing I'd try before tearing the bedroom wall apart is: shut off all water in the house (turn off the water heater power during this experiment). Relieve pressure in the system by opening both hot and cold faucets in the shower, and a fixture lower than the shower if you can find one. Then see if you hear the noise.

If you don't hear the noise, it's possible you do indeed have a leak and it's probably time to cut a hole in the bedroom wall to expose the plumbing in the shower and have a look. It could be pipes expanding and contracting, but the noise usually stops when temperatures are stable. Try turning the cold water back on, but leaving the hot off and see what happens. And vice versa.

If you still hear the noise, you've pretty well ruled out the house supply plumbing, and it's probably time to cut a hole in the bedroom wall to have a look . Seriously, in this case, we need more information. What's the layout of the house in the area of the shower? Anything above it? Can you narrow down the location of the noise using a stethoscope? Have you had a lot of rain lately?

You could cut a smallish hole in the wall near the floor (about 1 1/2" above the floor would be good) in the bedroom. Just big enough (like 2") to have a look in there to see if a) you can hear the noise any better, and b) if you can see signs of water. A 2" hole would be easy to patch.

The house is a ranch so there's nothing above it. Below is what we call a Michigan basement - in other words, not a useable basement and not a crawl space - it's just big enough to stand up in and where our furnace and hot water heater are. My husband was just down there and said he noticed no signs of water underneath the shower area.

This bathroom is a private one off of our bedroom, and it's on an outside wall. We've had rain but my husband cleaned out the gutters on that side of the house just in case it was a roof issue, and also looked up in the attic in that area but again, no signs of water or leaks.

What I find strange is that sometimes it's associated with using the shower, and other times it doesn't seem to be. My husband took a shower this morning (6:30 am) and I could hear the noise start right after he left for work, and it continued for awhile afterwards. About an hour ago (11:30 am) I noticed I wasn't hearing it anymore, so I turned on the shower and let it run for several minutes, then turned it off, and sure enough, I heard the noise start again, so for those instances, yes it's connected to shower use. But there are times when it's not - if he takes a shower in the evening say about 8:30 or so, I'll suddenly notice this 'drip' later on when I'm reading and it's quiet in the house, like around midnight. And that's what doesn't make sense to me. Or he'll take a shower, we'll hear the noise for awhile, then it'll stop, and then I'll suddenly notice it again a couple of hours later. Now yesterday he removed the faucet itself and the plate around it and shined a flashlight into the hole to look inside the wall in that area,and he said it was completely dry from what little bit he could see. We know that doesn't mean anything, it could be wet in another spot back there, but from what he was able to see, he saw nothing that looked even damp. Could it be dripping from the shower head inside the wall? (sorry, don't know the right names of things), and could he do something from the shower side to repair it?

I find the stethoscope interesting - would using this pinpoint exactly where it's dripping, if that's what it is?

I've used what we sometimes call a "mechanic's stethoscope" to pinpoint the source of odd sounds in engines and other mechanical components. It looks like an MD's 'scope, but instead of a cold rubber thing on the end, it's got a long metal probe you can place on the area of interest. They're very accurate in locating the source of mechanical sounds.

It strikes me that if you can hear this from all over the house, it's a huge drop falling from a pretty great height onto a hard surface or a puddle of water, none of which is consistent with finding no signs of water or dampness. I'd try the stethoscope thing (even an MD-type 'scope) to confirm that the noise is coming from inside that shower-wall space. I'd also put the 'scope up against various pipes to see if the sound is coming from within the plumbing somewhere.

Can you hear the noise when you're crouching in the basement or the attic? I'm especially interested in the basement. Also, get up on the roof and listen in the vent pipe. It's a shame these drips don't happen more often.

Do you have a shower plumbing access panel in your bedroom? If not, now may be the right time to cut out a section of the wall and put one in. They're good to have in situations like this. Do you notice this drip on days that are dry and not humid? Could be a condensation thing.

Are you sure its from the shower, could be an issue with the toilet which could come and go with vibrations due to movement within a room...

Well, hubby has been working on this for the last two hours, and we think we fixed it....we'd been having problems for maybe the last month with air in the pipes, so we turned the water off then turned it back on, first cold then hot, and did some other things I don't understand, and after all that we don't hear the noise anymore, but what we are seeing now is sand in the bottom of our tubs and sinks....yeah, I'm pretty upset right now. We narrowed it down to the hot water tank, so my husband is now in the process of completely draining the tank. He drained some from the bottom like you're told to do every now and then, but everytime we turn on the hot water, we still see dirt. He said it could be in the lines but he's emptying the tank anyway. I'll let you all know how it turns out....this has turned into a nightmare.

Your probably on the wrong track. It sounds to me that it is an expansion/contraction noise. If your plumbing drains are PVC, run some hot water then stop and listen. if the noise picks up then you will know that's what it is. Try that then post us back

↑ True Dat ↑

Well, I thank you guys for your help, it's truly appreciated. We finally got the water to run clear after completely draining the tank and letting the water run for awhile, so after 3 hours of 'playing' with everything, we were quite relieved that everything was fixed....I was wrong. He took a shower last night about 8:30, and after he went to bed about 10:00, I was sitting down to read and I heard the 'drip' again....and geez I really hated to tell him after all that work he did.
But he agrees with you, plumber1. He can find no evidence of water anywhere, not behind the shower wall, not in the basement, nowhere. And it doesn't sound like a drop of water to him. Now, I did do the test yesterday that you suggested before I wrote here, where I turned on the hot water in the shower and let it run for a bit, then turned it off, and I heard the 'drip' start. But as I said earlier, the sound I'm hearing is similar to you clicking your tongue against the roof of your mouth, you know that sound that kids like to make. My husband also thinks it's the pipe itself just making 'noise', but my question is - if it is expansion/contraction, why is it just starting now?

noise

Some where there may have been a minute shift where PVC meets wood and expansion will happen and pipe rubs against that wood.

The plumber may not have provided for that.

After a while you won't even hear the noise.

If it is expansion/contraction it might have always been happening but just not audible. As the house settles and things shift it might allow enough play for the sound to happen.

A water leak in the house rarely makes a sound. The sound of water hitting drywall or wood isn't as audible as the sound of water dripping in a hollow, hard, resonating pvc/abs pipe.

Could it be that it's not a leak in the water supply or drain, but rather the sound of water dripping in the vent. I had a similar 'issue' in my new home after 2 years, and I notice that it happens only in the winter. After 4 years, I haven't had any water damage (yet), so I'm pretty sure it's condensate of some sort dripping down. I once opened up my drain vent in the attic in the winter (for other reasons) and was amazed at how wet it was inside in the pipe. There's a huge temp differential btn the hot air of the house and the cold air above the roof. I imagine that in some climates even in the summer, you might get enough of a differential to cause signif condensation. Just a guess.

I used to live in Rochester, NY. There, they required a 4" vent through the roof to accomodate the ice buildup inside the vent. I thought that was pretty weird, but went up on the roof and looked one wintery day. They knew what they were talking about; wish I'd taken a picture.

One other possibility is that it could be a pinhole leak in a pipe in the wall. The water could be spraying up or sideways and pooling in one place. This could account for a rather loud dripping sound at irregular intervals.

If it was expansion/contraction, it wouldn't take 1.5 hours for it to occur. That sort of thing happens almost immediately.

Ok, we figured out what it was - or at least we think we have - it's the pipe hitting the wood inside the wall. My husband took off the plate behind the faucet and could make the same sound by tapping the inside with the pipe, but how do we stop it? He's tried two times now to put a piece of foam in there, and also by slightly tightening the pipe, and this second time the pipe didn't move at all when he was finished, but we're still hearing it. I don't get it, it's 12:30 am right now, there has been no running water in the house from showers, laundry, dishwasher, nothing, since 8:00. I sit down to read in the living room thinking it was gone, and I no sooner sit and I hear it again. We are sure that's what doing it - but what do we do about it?? I already posted here a little while ago telling you guys it was fixed but I see now it isn't so I deleted my other post and guess I'm still asking for suggestions. This is soooo frustrating, you have no idea.

Try turning valves off one at a time. Start with your toilets, since they are often a cause of noisy pipes. If you turn off a valve and the noise goes away, then you know that's the problem area.

You can also try using a wooden shim instead of foam.

If you get a can of expandable foam (around here it goes by the name Great Stuff) and fill the cavity behind the shower with it, those pipes will stop rattling, but you won't endear yourself to any plumber that has to work in that area in the future. You could just spray it around the pipes, but I get the impression there's not sufficient access to have much control over where the foam would go. CAUTION -- if you do decide to try this, be careful which of the three types of foam you use. Get a low-expansion foam -- Great Stuff's is in a blue can, marked for "doors and windows" -- or you'll wind up with a wall full of expanding foam which won't stop when it hits the wall . Your 3 1/2" stud cavity will end up being about 5" thick.

Expandable foam we never thought of - you can use that in there? My husband did do what verdeboy suggested and put a wooden shim in there this evening, but I can still hear it - do you believe that? It's almost as if the sound moves, because now it sounds like it's a little deeper inside the wall. You're also right about very little access back there...there's barely enough room behind the faucet plate for him to do anything. I don't know if we can even get the foam where it needs to go. Would we need to fill the entire space back there?

It's very possible that a shim in one place anchored the drain line and then move the tight part somewhere else.

I personally don't recommend the expanding foam. You'll probably just make a big mess and not solve your problem. That stuff is generally used to fill large openings around pipes, where you can easily get at them.

Try adding additional shims or using pipe straps, clips, or hangers to anchor the pipe to the nearest stud or whatever is closest to the offending pipe.

Did you try shutting off your toilets? Toilet fill valves are notorious for creating pressure changes, and thus are a primary cause of noisy pipes. I'm assuming we're talking about a water inlet pipe and not a drain pipe. Am I right?