Things that go bump in the night

[Paul MacLean]

I just got a call from a client I inspected a small condo for last July 7. This is an 8 unit complex and his unit is on the ground floor with a unit directly above him. The building is 20 to 30 years old.

The problem is that he is hearing a loud, sporadic bang, thump or knock coming from the living room ceiling. He says it sounds like someone bouncing a hard ball off the floor in the unit above. The guy above says he is not making the noise and that he doesn't hear it.

This has been going on for about three weeks and occurs mostly at night (keeping my client from sleeping). The noise will start in the evening and become more frequent as the night goes on, and then gradually stop in the morning...no banging during the daylight hours.

We talked about the possibility of water hammer, but the frequency doesn't seem to correspond with any faucet operation, etc. He knows what the popping of a water heater with deposit build-up the tank sounds like and says that's not it.

The building is all electric and the HVAC system I reported is almost 20 years old. The heating system is forced air with electric coils and a central AC with a common blower. The ductwork is all hidden between floors. I didn't think to ask if he changed out the system as I recommended in my report.

Any ideas out there? I'm just trying to help my client out and don't know where to go from here. Who should he call (like they are going to come out in the middle of the night and wait for the thump)?

Any and all ideas will be appreciated.

Paul in Austin

[Jim Morrison]

Paul,

I'm thinking the upstairs neighbor is being less than forthright. But then, I'm just one of those simple inspectors who, when he hears hoofbeats thinks "horses", not "zebras". Know what I mean?

Jim

[kurt]

Is there an ejector pump or sump pump in the bsmt. w/ a check valve? Sometimes the checkvalves thump when they shut down.

Or, the neighbor is psycho & is toying w/your client.

[Terence McCann]

Hello Paul:

That's a weird one alright!

First I would check the water pressure at night. The pressure might go up at night in a slow usage time which, might account for some type of hammer. We just had a PRV fail in our neighborhood which can do strange things like toilets that won't quit running but no banging noises were heard in our condo complex, single dwellings attached at the garages. It would be strange however that it would go on through the night (a usage thang).

The HVAC ducts/furnaces might do this if it were very cold (thermal expansion thang) but again, that's a long shot.

You would have to see what has changed in the last 3 weeks - weather, etc.

One other thing, it might be some type of varmint that has found a way in and is building some type of nest?????[:-mouse]

Only way to really pinpoint it is to be there when the noise is occurring I'm afraid.

Have $$$ will travel!

I just saw that you are in Austin. I guess the cold temps are out of the questions. BTW, my daughter lives in Austin. Moved there after getting out of the Navy with her husband.

In thinking a little more about this it could be a secret tunnel for illegal aliens from south of the border----[:-alien]

[swarga]

This is intended to be a realistic response, not a joke.

The upstairs neighbor is having sex. He doesn't here it because he is preoccupied.

I had a situation very similar and that was the reason for the noise. The upstairs neighbor but his bed posts on rubber pads and moved the bed three inches away from the wall and the noise stopped.

[Terence McCann]

Scott:

Brings a whole new meaning to "I hear ya knocking!"

[Paul MacLean]

Originally posted by Terence McCann

Hello Paul:

That's a weird one alright!

First I would check the water pressure at night. The pressure might go up at night in a slow usage time which, might account for some type of hammer. We just had a PRV fail in our neighborhood which can do strange things like toilets that won't quit running but no banging noises were heard in our condo complex, single dwellings attached at the garages. It would be strange however that it would go on through the night (a usage thang).

The HVAC ducts/furnaces might do this if it were very cold (thermal expansion thang) but again, that's a long shot.

You would have to see what has changed in the last 3 weeks - weather, etc.

One other thing, it might be some type of varmint that has found a way in and is building some type of nest?

HVAC ducts were one of my thoughts - the system is at the end of its normal life and I recommended replacement.

Plumbing is a possibility, but noise pattern doesn't fit.

Varmints are another thought, but the noise pattern seems to regular.

Keep the ideas comin'

[Paul MacLean]

Originally posted by kurt

Is there an ejector pump or sump pump in the bsmt. w/ a check valve? Sometimes the checkvalves thump when they shut down.

Or, the neighbor is psycho & is toying w/your client.

Slab on grade with no pumps. The psycho neighbor is always a possibilty.

I'm still listening...

[Paul MacLean]

I've passed on Scott's sex story and Terry's thoughts, anonymously of course.

You guys are great! Keep'em coming.

[kurt]

I vote sex. It's the most interesting theory.....

[Rob Amaral]

Maybe the guy is tossing in his sleep and hits the wall and doesn't know it...

My Godfather punched the wall all his life in his sleep after 10 days of "hand-to-hand-hell" on Peleliu and then months of the same on Okinawa... He never let up.