After I use 2nd floor bath tub(shower pan), I hear a dripping sound inside the wall. The sound lasts long when the shower is taken long and it lasts short when the shower is short. Luckly (^^) I have not found any water mark on the kichen ceiling which is directly below the upstair bathroom and on the basement ceiling, either.

I hired a handy man to look at it since I thought it was shower pipe leaking (although there was no water mark. How stupid I was... ). He tear off the dry wall and found it was dry inside wall and under the shower pan. It cost me a fortune to put back the dry wall. @.@

Then the handy man went to the basement and concluded it was water dripping inside the drain pipe. I put my ear against the drain pipe and could hear a water drop hitting the bottom of the pipe. Since this drain pipe is perpendicular from the 2nd floor, the handy man explained the sound echoed inside wall and created a loud dripping sound.

OK. This is what I found so far.

I want to get rid of this dripping sound, but there is no slow draining in the tub. The handy man says the hair buildup could be hanging from trap arm causing a little dam to let off the water little by little.

Since this supposed hair buildup doesn't entirely block the drain pipe, I don't know if I should use a hand snake or chemical cleanser. A hardware store clerk told me either of them wouldn't do much good.

So, here are my questions;

1. Is there any other way to get rid of this sound? I tried pouring a bucket of hot water down the drain, but loud popping sounds scared the whole out of me.

2. My house is 35 years old. Wouldn't using a snake or a chemical cleanser damage my old pipes? It seems we have iron pipe from drain to drain pipe and drain pipe is A.B.S.

3. Is it possible to see a water mark long after leaking has started? Although I think I heard the dripping sound inside the drain pipe, it scares me that there might be a real leaking that I didn't find. So whenever I hear this dripping sound, I run down to the basement and check the drain pipe. It's very tiring.

In other words, do we always find a water mark whenever there's leaking?

Sleepless in Toronto, Canada

P.S.: toilet and sink on the 2nd floor don't make this sound.

You will get a water mark on wood or drywall and once it is there it will be there forever. Leaks leave marks on wood and drywall 100% of the time. I'd have the handyman rod your pipes rather than trying chemicals. "but loud popping sounds scared the whole out of me." Could you explain this in a bit more detail? I am skeptical of the theory that water drips 2 stories inside a cast iron pipe and echos.

Thank you for your response.

I read pouring a pot of boiling water could resolve the buildup and the regular use of it prevents the future buildup. So I tried.

As soon as I pour a hot water, there were 2 banging sounds in the wall then disappear. I got scared so next time instead of using a boiling water, I just simply let the hot tab water run down the drain for about 2 minutes. Then I heard this bangging sound again.

Ah... I said 'popping sound' in the previous question. Sorry. It was more like 'Bang!'. Probably pipe expansion, right?


And about the dripping sound. It starts 5-6 seconds after shower is done, then drip drip drip for about 5 minutes then gone.

Yep, if you pour boiling water into a two story cast iron pipe you will get some expansion but don't let it worry you. A quick home remedy for cleaning drains is 1/2 cup salt, 1/2 cup of baking soda thoroughly mixed. Add a cup of vinegar and quickly dump into the drain. Allow to sit over night and then flush with your bucket of boiling water. POP POP. However, I'm still thinking the drain isn't the source of you dripping sound but I've run out of ideas since you say everything is dry. Sorry.

If you decide to snake the tubs drain line and need instructions on how to do it click on back and we can walk you through the process. Just let us know, Regards, Tom

The more I think about it I'm leaning toward that dripping noise to also be expansion related, actually contraction as your shower pipes cool. That's all I could come up with. It may sound a bit like a click, click, click.

Thank you for your time and all your answers. I actually hired Mr. Rooter guy the other day, and he confirmed that it was contraction.

I examed it with cold water running only cold water for more than 5 minutes and listened to the sound. Guess what. No sound at all.

I spend about $100 for 2-minute counselling on Mr. Rooter guy, but it was worthy spending 'cause I stopped to put my ear against the wall listening to drip drip drip drip...

So I wasted a fortune on Mr. Kang for the perfectly good bathroom, huh?