Mystery Leak behind Shower Wall

Old 07-06-05, 12:37 PM
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Mystery Leak behind Shower Wall

We have a mysterious problem with our main shower/tub that has existed a long time. I'm betting the problem existed before we bought our house in 1986. No, we didn't have an inspector because it was a seller's market then, and we really wanted this neighborhood and we were advised to put bid in right away. Yes, we acquired some hidden problems, and we swallowed hard and paid to have them fixed. Different story, too late to do anything now.

The problem with that main shower is that it eventually will start leaking onto the ceiling of the family room. It never shows up right away. Actually, it can take weeks to appear. We discovered the leak when we had to use it because our master shower leaked into the garage (we did try to fight that one and lost). Anyway, it was nearly a year before we discovered the new leak even though the tub had been used regularly by our 5 year old. She didn't take showers--only baths. It was when we showered, that the leak materialized.

Since we had a new baby, life was really too busy to worry about the shower, and with our new one repaired, we just ignored the main shower. After several months, I called the first of many plumbers to take a look. No leak could be discovered even with running the shower. Suggestions were good to silly. The good ones were (1) caulk everything again, (2) regrout the tiles (did both of these). The silly ones were suggestions that our kids poured water on the floor and then cleaned it up before we found out. No, the leaks occurred when the shower was running and stopped when the shower stopped.

Looking behind the wall in the access panel in our older daughter's closet, you could see the wall board area that the faucet was attached to (just a small area) was damp at the bottom. Looking up, the shower head did not leak.

We thought maybe it was the old original compression fixtures that leaked and needed replacing anyway, so we had it replaced with a Moen pull-out one-handle kind. Nice. But, you guessed it, the leak returned. We had that plumber out two different times; each time, nothing. I think he thought we were crazy, too.

More years went by and we had two kids using our shower. We just got too busy to worry about it. We'd use it occasionally, or we'd let guests use it because for one-time uses, it wasn't a problem. This year, our older daughter (who was five when this started) was getting married (now she's 23), and we thought about house guests who might be using it.

I got the idea that we had to use the shower enough to get it leaking and get the plumber to come while it was leaking. That turned out to be a smart idea because, he actually saw the wetness behind the wall. When we ran the shower, nothing happened, but when we splashed water on the faucet wall, he could see wetness appear.

His suggestion was to have everything retiled (expensive) or have a fiberglass tub surround put in (not cheap either). With a rapidly approaching wedding, we opted out of those suggestions. The reason he suggested this was because he said the tile itself was leaking--not the grout. I have never heard of this. I said thanks and let that go.

I asked a handy friend what he thought about the problem, and he agreed that he never heard of tile leaking. However, he said one way to isolate if it was the tile is to hang a plastic sheet over the faucet wall and use the shower for several weeks. If it leaks, there's something going on back there that no one is finding. If not, it's the tile and then we go to plan B.

Any thoughts on this? And, yes, we've put up with this way too long. And, in addition to the older one getting married, the baby who was born in the house is now going off to college. We can procrastinate with the best of them. Thanks for not laughing too much.
Old 07-06-05, 03:31 PM
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First thought was leak at shower arm attachment to drop ear elbow on riser from valve. New valve would eliminate leak at connection at valve, but you had this valve replaced. There could be a pinhole leak which leaks when the riser is pressurized, but this would be apparent from the access hole.

Second though, leak from bad grout. You already have caulked the the trim and edges (most noticible areas). Cover with plastic would be an idea to check this for the leak.

Good luck with your leak...
Old 07-08-05, 05:27 PM
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Hi, Seems like your not in a hurry. This idea is like your but 180 out.
Don't use the water in your shower durning this test. take some newspaper and crumble it up and stuff it in the inspecion hole just below the tub spout,let it set about a day then check it for dryness if still dry take a garden hose and flood the wet wall below the tub spout. I wouldn't use a nozzel on the hose too much pressure and less control. Keep the water in the tub not on the floor. Check the paper if after a day or two and the paper is dry move up the wall with water small sections at a time this will help you isolate the leak.
Good Luck Woodbutcher
Old 07-11-05, 04:55 AM
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Thanks for suggestions

Thanks for the feedback and suggestions. You are right, we're not in a huge hurry, but it certainly is something I'd like to resolve before next year--the 20th anniversary of living in this house!

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