Drain layout?

blackstar

Hi all,

Can anyone explain how our drains may work?

I live in a terraced house in the middle, there are 6. Im the 3rd one down.

So we have a manhole about 4 feet away from our back wall under our decking. The water runs ofcourse in one direction only. When our neighbours upstream run their skins or shower water flows though it. However when they flush their toilets nothing comes down it?

So does that mean theres a seperate drain pipe for dirty water and one for clean water? And if so are they connected at some point somewhere as I know when the drains got blocked not long ago the smell from this clean water pipe was horrendous so I presumed there was just the one pipe, one for bith dirty and clean water. Scottish water unblocked the drains from this drain under my decking.

But as I have discovered this evening when my neighbours flush their toilet nothing flows through this drain? Anyone maybe explain how our drain system may work?

Ive added photos to show how the drains etc are. The thick back drain is the toilet drain and the grey ones are for the bathroom sink and kitchen sink/washing machine.

bjorn_toby_wilde

How old is the terraced house?

Nowadays foul water (there’s no distinction between what comes out of the washer, dishwasher or toilet) goes through the foul water drains (sewers). Rainwater from your gutters however goes into a separate storm water drain.

In older properties (think Victorian and Edwardian) all the water went through the same pipes. The downside of having it all go through same pipes was that storms could overwhelm the drains and flood your garden with sewage as well as rainwater.

It’s a bit unusual that your some of your neighbour’s foul water is plumbed into that sewer but not the toilet. The neighbour’s toilet sounds like it’s plumbed into a different foul water drain. Depending on the layout and the slope of the ground it might go in a different direction maybe.

blackstar

Thanks..they were built in the 1940s.

Sounds like my neighbours toilet foul water drains.into a different foul water drain somewhere then. But where? And how do I find out the layout. Scottish water said they dont have a map, only the ones that run in the main roads not the ones under our back gardens. But the ones under our gardens must still connect to the ones they have on their map under the roads musnt they?

bjorn_toby_wilde

The pipes under your gardens will connect to the road somewhere, yes. The pipes are normally accessible so they probably run along under all the back gardens then there will be a connecting run down a driveway or alley between the houses to the road.  There might be one either side of the terrace and your neighbour’s runs to the other one for example.  Look for a manhole in a drive or alleyway.

Albermarle

What happens when you flush your toilet- do you see it in that open manhole? or does it also go somewhere else ?

blackstar

Albermarle said:

What happens when you flush your toilet- do you see it in that open manhole? or does it also go somewhere else ?

Nope because our toilet is down stream from the manhole. 

So why is it that both neighbours upstreams toilets do not flows into my manhole at all. Only their sinks, showers and baths do.