What the hell was this vibration in our wall?

The weirdest thing just happened. Ok, maybe not as weird as a poltergeist bringing me a glass of water, but still weird. My husband and I were sitting in the living room when we heard a loud vibrating noise. I thought it was a plane outside, but it kept on too long for that. He felt a wall and said that the wall was vibrating. The wall is an inside wall, and the guest bath is on the other side. I went into the bathroom and realized that the tub spigot was vibrating. I turned on the water for few seconds, then turned it off and the sound stopped. What the heck was that? The only other thing I can think of to mention is that I had a sprinkler on outside that is on a timer and should have turned itself off sometime in the last half hour or so–I think earlier than we heard the noise, but maybe not, as I didn’t really watch the time when I put it on.

Sometimes as valves close, the water can vibrate, just like you can whistle with air. It may very well have been your sprinkler.
Or, of course, ghosts.

Are you sure it was just that wall and spigot that were vibrating? It could have been an earthquake.

Maybe air in the line? Could you have a small leak somewhere, or some flaw that would let air into the line? Did the city turn the water off for a time? I’m reaching a bit with these questions, but I have seen pipes vibrate due to a leaky sink and the city turning the water off for a few hours. Air got into the lines.

The last time that happened to us, it was the earthquake leading to the Boxing Day tsunami of 2004. Our windows were vibrating, and we had no idea why. Look at a map to see how far away we were, and you’ll see how impressive that was.

Water pipes are great sound conductors. I can harmonics when I use a watering wand to fill the watering can, which acts as a speaker. I wouldn’t be supprized that towns with people complaining of nose other’s aren’t affected by are hearing noise carried to their home by water pipes.

I would suggest you check your water heater pressure relief valve now to see if it went off or is currently pouring out water. The discharge sets up one hell of a vibration, often heard in the rest of the house.

Thanks, everyone. Not an earthquake–although we are not that far from the New Madras fault, the vibration was clearly localized in that one wall. I checked the heater relief valve and it is fine.

When my husband and I retraced our steps, it became clear that the timing did coincide with the automatic sprinkler turning off. I had the water on higher pressure than usual, so that may explain why we had not heard something like this before.

I Am Not A Plumber, but as I understand it, you’re describing “water hammer”. Shutting off a valve or spigot or tap or faucet or whatever, especially if done quickly like many automatic valves do, causes sudden back pressure. Usually it’s a single knock, but if there’s any flexibilty in the pressure - hoses, airlocks, etc - it can reverberate back and forth for a while until the system settles down.

And yes, it can be alarmingly loud.

Water Hammer was thought to have caused the recent steam pipe explosion in NYC.

It’s time to face facts…
…you’re Cylons.

Check the deed history of your house. Was it ever owned by Sue Ann Nivens? Is there a coin-slot in the wall?

While conceivably an awesome (colorful) name for a fault (torn fabric), might you be thinking about the New Madrid Fault/Seismic Zone?

Telling me. The hot water tank in my house is in the airing cupboard which is in my bedroom. Often when someone takes a shower we get very loud and annoying water hammer in the pipe leading from the tank. It used to make the pipe vibrate to such an extent that it actually moves sideways and hits against the side of the hole where it goes through the floorboards. I fixed it (or at least made it less annoying) by wedging the pipe so it couldn’t move in the whole. The pipe still vibrates but it’s not as loud.