Our home was built in 2001. It is a 1 1/2 story (no upstairs bath) and we have a post-tension slab. (we are in TX) For the last 4 months or so, at no particular intervals or times we get a sound coming from the center of our home through the walls that sounds like someone has turned on a vibrating back cushion or something. It will last 30 seconds, maybe less. I am home 90% of the time, and can say that this may occur once in a month, or twice in one day, and then not again for 2 weeks. I am assuming it may have to do with the main stack, which is in that area.

It appears to be completely random, as there is no correlation to flushing a toilet, doing laundry, taking a shower, ringing a doorbell, using the internet, heat or A/C or opening a window! That has been the most maddening part of the whole thing. It can be 70 degrees outside or 20. Day or night. Full moon or New moon... nothing ever seems to be a clue.

Also- and this MAY or MAY NOT be happening together, my slab seems to be trying to break apart from the front half of the house (main bath forward) as I have some enormous cracks growing in the ceiling and floors. It's like the front half of my house is trying to migrate farther south.

I do not have (many) issues with clogs, draining, etc. although the main bath toilet has never flushed as good as the one in the master bath at the back of the home. We have Toto low flow toilets, no issues with ball cocks or anything else. Just a weird vibration in our home.

Do I call a plumber, a foundation specialist or Ghostbusters?? Any ideas? Thanks!

Have you ever blown over the top of a bottle and heard the hum? I have noted a hum in a house when the wind blew over the vent stack. Solved it by putting a wind diffuser on top. You might want to look at this as a possibility.

But if it was just from wind, why wouldn't it have happened previously in the 12 years we have lived here? We bought this house new. This has just started the last 4-5 months or so.

Didn't say when you bought the house just that it was built in 2001. It could be slab slippage if you are having slab issues. In that case you may need to have a foundation company look at what they can do to keep the slab from separating. I just worked on a house where the driveway is slowly sliding down the hill, 1/8" per year, already moved 2"!!

Our house has slipped forward 1"+ . So here is an additional question I cannot seem to get answered... we turned off the water @ the main to see if we had a detectable leak, we got no answer that way. Is it possible that there is a leak (however minor) in the outflow that could cause #1- pressure issues that give us this occasional vibration and #2- also account for the slab movement?

As you can imagine, with our drought issues the past few years even with keeping the yard/slab watered we had attributed some of the movement to that. But now with this newest weird noise issue we are starting to think there is more going on than just Texas clay.

Thanks for your input!

Outflow? Are you talking a drain? They are not under pressure and wouldn't make any noise. I'm surprised you haven't had pipe leak issues with a 1" movement. Pipes are buried in or under the slab.

Hi moose

I'd start by trying to detect the smallest of leaks. To start, I would drop about 20 drops of a dark food coloring in the toilet TANK(s) in the house. Wait an hour and then return... if colored water is in the toilet BOWL(s) then you may have found the source of the humming!

Here, when a toilet tank flapper allows water to slowly leave a toilet tank it can cause the toilet tank to refill while only engaging the toilet fill valve just a little... causes a humming/vibratory sound.

I'd check/eliminate the toilets first and then look at other options!

Mark

Thanks I will give that a try today :)