Help: Noise @ Night

[Scott]

I live in a 39 story condo building, my unit is on the 36th floor. The building is 3-years old. Over the past three weeks, we have been awake every night at approximately the same time due to some knocking noises in the walls.

The noise is hard to explain, because I don't know what is the original noise and what is the echo, but a knocking noise is probably the most accurate. The noises are not constant, they come and go almost randomly (lasting from 5secs to 30secs with breaks of various lengths in between). The noise usually starts between 2am and 3am, and can last for up to 3 hours. It sometimes happens during the day, but always happens at night.

Property management is stumped, so I was hoping I could get some advice from this newsgroup... We need our sleep!

Thanks for any help -

[No]

Weird if it just started. My first thought would be water draining but that couldn't be if it just started. Could it be something loose on the exterior facade that is blowing in the wind? See if the sound coincides with wind. Could a bird have nested somewhere? An owl maybe?

[Scott]

So far the noises have happened with/without wind, and we have checked all of the ductwork that vents outside (no birds)...

You mentioned water draining... Could it be that something has blocked a drain somewhere in the walls?

-Scott

[Sacramento Dave]

Thermal expansion on the hot water side may cause the noise from the expansion of the hot water. Next time you hear the noise try turning on the hot water, maybe let it run low in a room you can't hear it in see if noise stops. What your trying to do is relive some pressure.But I would think in a building this size they would of accounted for this. Do the other neighbors hear the noise? I would check with tenants above you, see if they hear it could be equipment on roof. Any ghost sightings? might need exorcism.

[No]

Not likely - The sound of rushing water in a drain pipe in a wall is a typical complaint in new residential construction. The sound is there from day one. In your case, something has changed. Either something was added or broke.

Added - birds, rodents, neighbors, new or upgraded hvac components, plumbing, appliances, etc. Broke - HVAC equipment, appliances, etc.

Dave suggested thermal expansion. I like that idea. Are you in a climate where you still need heat at night? Maybe for a little bit? Is your heat baseboard hot water? Those popes can make noise when warming up or cooling down. Could be your neighbors pipes you are hearing too.

[Scott]

We have checked with the neighbours, and they have not heard anything... As for the heat at night, we rarely dip below 70-75 at night so the heat is not triggered.

Thanks for your help!

[Scott]

I have tried running the hot and then the cold water during the noises. Nothing seems to make an impact. We have checked with neighbours, and they have heard nothing (likely meaning that the noise is somewhere within our walls).

-Scott

[CL (dnoyeB) Gilbert]

My first thought living in a 39 story condo would be a headboard.

[Sacramento Dave]

My first thought living in a 39 story condo would be a headboard.

That dose make more sense than my heat expansion or Ghost theory. Hmmmm OH YEA if this room is rocking the walls are knocking.

[Doug Kanter]

I think your theory wins the grand prize. :-)

[MAG]

For three hours at a stretch! Ohhhh baby!