intermittent leaking shower/tub

[aduff]

I have a strange problem. My shower leaks about every 10th time we use it. It drips down through the ceiling below. If the shower has been on for a while it'll run in a stream until you turn the shower off.

I can't recreate the leak. I've tried directing water down the overflow. I've tried stopping the drain and just running the faucet. I've tried not running the water through the shower head. I've tried all hot, all cold, low pressure, high pressure.

I don't know if standing in the tub makes a difference or not. It has definitely never happened when no one was in it.

Any idea why it would just leak sometimes? It makes me think it isn't a plumbing problem because if a pipe leaks, it leaks all the time, right?

There are a few small cracks in the grout in the tile on the wall around the tub, but they are really small. Could enough water get through something like that to pour in a stream from the ceiling below? Thanks for any help.

 

[Verdeboy]

There are a few small cracks in the grout in the tile on the wall around the tub, but they are really small. Could enough water get through something like that to pour in a stream from the ceiling below? Thanks for any help.

Yes.

Try directing the water to different parts of your tiled wall, at where your tub and wall meet, and also behind your tub spout and other fixtures, 'til you home in on the leak. Note: fixtures should have caulk around them to prevent leaks. The caulking between the tub and wall should be caulked as well.

 

[Sponsor]

 

[Geniescience]

.... been on for a while it'll run in a stream until you turn the shower off....

seems to build up first, and then break through after enough showers. That is strange.

Tub-shower. Nobody takes baths, do they? I remember one tub that caused massive streams downstairs occasionally.

david

 

[Jadnashua]

I'd check two things: is the tub actually level; and can you notice any deflection when you are standing in the tub.

Is the tub acrylic, fiberglass, cast iron?

Do you know anything about how it was built? Do you have an access panel you can look through? Normally, the tile flange (it might not have one!) keeps water from getting over the edges and leaking into the walls, but that doesn't work if it is not level (some are very shallow lips!).

 

[aduff]

I found a separation between a couple of tiles on the bottomside of the shower knob. I pushed on them and they gave in a bit. I guess whatever they're set on is rotting.

I directed water on the break and it started leaking through the ceiling below. This is the first time that I was able to recreate the leak, so this is a major breakthrough! I guess that it's been leaking when the water deflects onto that wall. That would explain the intermittant nature of the leak and why I haven't been able to recreate the leak without anyone in the tub.

Unfortunately I don't have an access panel, so I guess I'm going to have to break out those tiles and see how much damage is done.

Thanks for all the help everybody!

 

[Jadnashua]

Two things come to mind: mastic instead of thinset, or tiling to drywall instead of cbu. It is also possible that the gasket on the valve cover is damaged or the valve is not set properly to allow it to tighten up and create the necessary seal. Most of them also have a gap at the bottom to allow any moisture that does get in, to drain out the bottom. depending on how long moisture has been able to get in there, you may have a major rebuild in store.