Loud noise like a thundering "waterfall" after neighbour flush

Hi there,

I am a bit worried as I've just bought a ground floor flat (in a block of flats), and I keep on being awaken at random hours of the night by what seems to be a thundering waterfall noise or fountain or a sound like water really falling hard (a bit like if some heavy rain was falling very fast on a shower screen) behind my walls in both of my bathrooms.

Sorry for the description, it's really hard to put words on it and every time I talk about this to someone they simply say that it's normal to hear noises on a ground floor.

However, there is a real difference between hearing water going down the pipes (when the neighbours open their faucet for i.e.) or normal flush.

This noise doesn't last very long. But again, the duration varies and it seems random. I have no idea what it is and would like to get advice from a plumber or somebody who had the exact same problem please.
Could this be a leak from their toilet? Is possible that it would come from other neighbours than the 1st floor?

I sometimes also hear like a humming noise that lasts forever after the "waterfall" noise.

Many many thanks, as your reply might reconciliate me with sleep!

Sounds like waste water from the units above. If it's PVC or ABS pipe it could be quite loud.

John

johnjh2o1 said:

Sounds like waste water from the units above. If it's PVC or ABS pipe it could be quite loud.

John

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Thanks John! Yes, I don't think it's cast iron as the building is 5 years old.

So you don't think I should be overly worried about it?

I guess I am trying to find out why I hear different "type" of noises:

- "smooth" noises when they flush (sometimes) or run water from sink etc - just water running down the pipes for a short period of time.

- and that type of really loud noise which is so different. It almost seems like the water would be falling out of the pipes and hitting the drywall. Now, it is just a description of the "kind of noise" it is, as if it really was running out of the pipes and hitting my walls, all the tiles would come off I imagine and the water damage would be very visible.

As I have not experienced this type of noises before, I thought there might be a leak somewhere. And also I found that humming noise afterwards a little bit strange, but if an experienced plumber tell me that it is quite typical in recent buildings, then it's big relief!!!

If water was to come out of the pipes, as a leak or more than that, you will have evidence very quickly and a case against your neighbors.
If there is no leak, then it's just noise.
I see that you are in London, England: are there plumbers in your town? if yes, call a few of them and let them give you their opinions.

Personally, I think you're over reacting.

The humming could be coming from a lift station pump.
John