Hello.

I just moved into a new house and am working through the particularities of it. The seller installed a new shower on the ground floor (above a crawlspace) and it has a noisy drain. I am the first to use the new shower. From that bathroom I can hear the sounds of faraway dripping. Like the sound effects from a horror movie when someone is walking through an old tunnel. There are also occasional far off bangs. I have located the source of the sounds as coming from the shower drain.

The Halloween sound effects are constant. They occur when I have water on in the house and when I come home after having no water on for hours. All of the drains in the house clear fine. The water meter does not show any water running.

The house was built in the '80s. It sites along the main street, and there are five houses that sit behind it that are part of the same build out. It is fairly obvious that the sewer lines for the houses behind mine have to come under (or close to) my property to get to the sewer main under the street.

Is it possible that I am just hearing the echoes of sewer lines coming in from behind me on their way to the main? Or is that impossible and it is more likely a problem with my plumbing? And, of course, if it is my plumbing, any idea where to start?

Thank you!

If they had the required P traps you should not hear anything coming from the drains. The water in them would effectively block the sound but also block sewer gasses coming in. Are there any foul odors in that room you notice walking in or if the door has been closed for any amount of time?

No odors at all. Just the noises.

Very odd... Detached single family houses, not townhouses or Apartment style condominiums, correct?

That's correct. Just a single family home. No water being used, no drains recently used, nothing moving on the water meter. Just the sound of dripping/barely running water and some odd clanks now and again. And I can only hear them from the downstairs shower drain (which is the lowest drain in the house).

Not sure if I need a plumber, a contractor, or an exorcist!

First, check to see if you have standing water in the PTRAP of the shower, i.e. remove the shower strainer and look into the drain... you should see standing water. If you do not see standing water then there is not a PTRAP installed and that is DEFINITELY a problem!

Next, if there is no PTRAP and you are hearing these odd dripping sounds when no water is being used I suspect that you have a small leaker at the flapper of one of your toilets. Here, I would suggest dripping say 10-20 drops of a dark food coloring into the toilet TANK only... wait 10 minutes or so and then look into the toilet BOWL... if the dye color shows up in the bowl then you have a leaky flapper and will need to replace the flapper. Replacing the flapper should stop the dripping noises.

Start there... post back with results and we'll see what's next!

Mark

Thank you, Mark!

The shower is a standing stall & I could only see that the pipe went down on an angle. So I went under the house and did not see a P trap. The 2x2 PVC continues down on an angle until it meets up with the larger drain. There is no room that I can see for a trap to between the floor. So that must be the case. However, there is zero odor coming from the drain. I would have thought one would come from the other.

I am doing the toilet test now, but so far they seem tight. There is one toilet in that bathroom & one upstairs just above it. The upstairs one would be my suspect since I caught it running once due to the flapper.

But it sounds like you think it must be the P trap. Does the lack of smell give any pause to the diagnosis?

Thank you again!

Jason

Hi Jason,

Lack of odor isn't necessarily a bad thing here... just means you lucked out and the sewer drains are probably pulling air into the system instead of expelling noxious gases!

A PTRAP needs to be installed, for sure. Further, when the shower was installed a plumbing permit is usually required, i.e. a plumbing inspector inspects the work and confirms it was done to code (vented and trapped properly). If a permit wasn't pulled, you may be able to contact the seller and have them pay for permit, inspection AND alterations to the existing plumbing work, if needed.

Waiting on info. about the food coloring test at the toilet flappers...

Mark

Air conditioner condensate lines can also create a dripping sound.

The toilet flappers all seem to be working. It must be the PTrap. I will explore the permitting issue with the city tomorrow.

Thank you again!