Leak in downstairs ceiling due to clog in upstairs shower drain?

[Pickngrin]

Last week, while someone was in the upstairs shower stall (right after I showered), I found water dripping from my first floor ceiling - not a deluge, but more than a few drips, enough to cause some ceiling drywall damage. Note that it was raining heavily that day. I then augured the shower stall drain and pulled out a few hairballs. The water had not seemed to be backing up in the shower stall.
I have not seen any evidence of leakage since that day last week, and it has rained heavily since that day.

I'm a bit baffled by this and am not ready to have the ceiling repaired yet. Could the clog have led to the leakage? Is there something else I should check?

The house was built in the early 1920s.

Thank you for any input.

 

[Jadnashua]

Is this a tub/shower, or a shower? How old is the shower? How old is the plumbing? Depending on the water and what's sent down the drain, plumbing from the 20's is probably cast iron, and it could have a hole or more in it. Even brass, could have a hole in it. It could also be that the shower pan (at that age, maybe made of lead) is shot. If the shower is newer, one report I was told about indicated that nearly 75% of showers built were not done according to industry standards.

 

[Sponsor]

 

[Terry]

I would not rule out someone showering with the curtain or shower door open either.

Steps to be taken,
Plug the drain and put water in the pan. Have someone step around the pan and see if that makes it leak.
Check the wall plate for gaps in caulking.
Look at the shower arm and head. Sometimes the shower arms will crack. Though if it's cracked, it will leak everytime you use it.

 

[Jadnashua]

FWIW, a properly built shower should be watertight prior to any caulk or tile is installed.

 

[Pickngrin]

Thank you for the responses. It is a shower stall, not a tub, and I don't know the age (bought the house 1 year ago), but it is definitely dated. I am pretty confident that neither I, nor my girlfriend, had the shower door open.
Terry, I will follow the steps that you suggested and will report back. I did not notice any leakage from the shower arm or head, but I will inspect more closely.
Thanks again, and also for runing such a great web site. I've learned a lot over time.

 

[Pickngrin]

A delayed update... it has been almost 4 months and the leak has not recurred. I am a little uneasy not knowing the cause of what happened.
Any ideas?
Thanks again.

 

[Standardairconditioner]

A delayed update... it has been almost 4 months and the leak has not recurred. I am a little uneasy not knowing the cause of what happened.
Any ideas?
Thanks again.

What Terry said in #3.

Bad shower habits. Or kids.

 

[Jadnashua]

Is this a tiled shower? IF not, can you detect any movement if you move around the shower?

 

[Pickngrin]

Neither of us has showered with the stall door open, and we don't have children. It is not a tiled shower (fiberglass perhaps?). I don't notice any movement. I'm puzzled.

 

[Standardairconditioner]

Last week, while someone was in the upstairs shower stall

I'm puzzled.

Who EXACTLY was the someone? And would you CONFIRM WITHOUT DOUBT that this someone did not make a mess in your bathroom?

Be careful answering that one without GUESS or SPECULATION and respond only with FACT.

 

[Pickngrin]

The someone was my girlfriend. There was no mess on the floor. I know because I was on my knees checking the drain for a clog.

 

[Widgit Maker]

By any chance is the shower head one of those pulsating type?

 

[Jadnashua]

The drain assembly on some fiberglass shower pans can develop micro-fractures, but more common is for some slight flex to cause the drain to open up around the edges and/or seal. Different people tend to stand in different places. It may be fine with nobody in there, but stand in just the right place, and it might end up leaking.

If the valve or shower arm or fittings are not leaking, that's the most likely suspect.

 

[FullySprinklered]

I've had a few calls for leaks that turned out to be from the roof. I've also owned an old house that had a roof leak but only during a heavy rain while the wind was coming out of the east. Rain blows in from NW to SW here most of the time, so it didn't leak every time it rained. The roof was metal shingles crimped together on the sides.
I went back on one call three times before I grew a brain and looked up in the attic. I could see water stains on the vent pipe which eventually directed the rainwater to the vicinity of the tub, where the leak kept showing up. I replaced the boot on the roof, and that fixed it. 4 in 12 pitch, thank God.

 

[Pickngrin]

I don't know if the shower stall is fiberglass or plastic. How could I check for flex around the drain? Remove the drain cover and visually inspect it?
The shower head is not a pulsating type.

 

[Jadnashua]

IF the flex is really bad, you can feel it when walking around in the pan! If you still have the ceiling below open, have someone look at that while someone else is walking around the shower pan in their bare feet. ANd, maybe have one person looking at the drain from above while the other is walking around in the pan. Two common areas of leaking caused by flex are at the drain, and maybe where the wall/pan meet. Much less common at a vertical seam in a corner, but if the walls aren't plumb and straight, the wall panels (if they are not integrated into one piece) may not make a proper seal. If there has been a lot of flexing over the years, there could be microfractures in the pan, or maybe even put a stress crack in the drain line itself. Often, the joints in the drain to the p-trap are solvent welded, but if they are tubular fittings, the nut(s) may have come loose over time, and the thing can leak.

 

[Pickngrin]

I'm resurrecting this thread because during very heavy rains and wind last night, I experienced leaking in the same exact place. This was only the second incident. It seems that water travels along the joist in that room. The shower appeared to have been a red herring. I've had pots on the floor catching water all night. Now I have to find the source of the water. I just put in a call to a good contractor I've hired before. Unfortunately, it will be dark by the time I get home today, so it will be difficult to do outside investigation. I was Googling during the night to try to come up with ideas of possible points of entry.
The site of the leaking is close to an outside wall and there does appear to be some breeze in the ceiling (can feel it with my hand and can see a very small piece of fiberglass insulation moving).

I'm wondering if the cause may be similar to what fullypsrinklered found (leak around vent pipe).

Any suggestions or thoughts?
Thanks again.

 

[Terry]

Blowing wind and rain can even cause water to come in around windows. I find that when the winds are from the South in the Winter, I get more calls for leaks.

 

[FullySprinklered]

I've been married three times. All three have tried to convince me that I've never been right about anything. Since we're not married, there's a chance I could be right. Does that make sense?

 

[Pickngrin]

Thanks again, Terry.