How to tell if its my Water Supply Pipe or Drainage Pipe thats Leaking?

AVENUE

I have an older terrace house & i can here water running constantly right at the back wall area of my rear yard. Is there an easy way to tell if this might be my water supply pipe or my drainage pipe? I dont have a water meter & although the water pressure does seem a bit low, it does vary quite a bit. The sound is under the area where the old outside loo would probably have been many years ago. Would both the Water Supply Pipe & Drainage pipe be located in the same areas?

I'm trying to avoid an expensive repair bill so would it be best for me to take out some insurance? I can get Water Supply Pipe cover for £3 a month....but this does not cover Drainage Pipes, i can get Drainage & Plumbing cover for £7 a month....but this doesn't cover the Water Supply Pipe, so would it be best to take out both covers?

I'm with United Utilities who offer a free one off repair to some leaks on water Supply Pipes, but say there are certain conditions and that doesn't cover leaks under buildings or in hard to access places. My leak isnt under a building but might be under my back yard wall, so dont know if this would trigger one of those restrictions? I.m a bit wary calling them out incase i end up having to foot the bill, which is why i'm wondering about the insurance.....any advice would be appreciated.

Best regards - avenue

muckybutt

Easiest way to find out if its a supply pipe is to isolate the water to your property which seeing as you are a terrace might also turn off a few of the houses so best let them know.

I had a similar problem many years ago, old terrace loo outside bee knocked down, lead pipe just hammered over to cap it off. I investigated and the lead pipe went...leaking everywhere. Couldnt turn the stopcock off in the street so ended up having to contact water board.
Thet replaced the stopcock however they also noticed there was a leak, two days later I got a recorded delivery letter informing me to get the leak fixed within 7 days or they would do it and charge me for the privilage....needless to say I repaired it by removing the lead pipe completely and replacing with mdpe pipe.

phill99

It's unlikely to be a supply pipe. It's difficult to hear the water running in supply pipe as its under pressure and creates a vacuum of water in the pipe.

If you could hear it running outside, it's possibly part of a main sewer or drain connecting a number of properties especially if its under an old outhouse.

Furts

Hello also consider your drains/sewers

Where are the manholes so you can lift the lids to determine are they surface water, foul or combined sewers?

You should be able to determine the route - are they passing through where you here water running?

Does the sewer have a flow in it?(If it is a surface water or combined sewer certainly expect a flow after the recent rain)

Does the location, flow or noise correspond to what you have been hearing?

anotherbaldrick

Have you got a large screwdriver ? If so turn off all taps and go to the nearest cold water pipe you can see close to where you suspect the leak is, put the tip of the srewdriver on the pipe and press your ear to the other end. If you have a leak you will hear the water escaping , it will sound like the roar of traffic when close to a motorway and sound quite loud.

macman

A drainage pipe will only leak if water is flowing into it. It's empty the rest of the time.

phill99

macman wrote: »

A drainage pipe will only leak if water is flowing into it. It's empty the rest of the time.

If its a communal drain connecting all the old outhouses and beyond, it's likely that its till in use and likely to have a fairly steady stream of waste going down it.

It could also be a diverted culvert you are hearing. They are often diverted via underground 6" pipes.

AVENUE

Thanks folks.....i can hear the water constantly no matter what time i listen. It sounds like water "hissing" out of a cracked pipe, but as its right at the end of my yard towards the end wall, there's no exposed pipes to look at. It could perhaps be that this has been going on for some while as my rear wall is very damp too! I cant hear it when i go out onto the back at the other side of my wall though, its an old back which is still cobbled.

macman

Have you done a flow test on the meter (if you have one)?

AVENUE

No i dont have a water meter i'm afraid. The water pressure does seem a bit down on normal though. If it was a drain that was leaking & had been for some time would i be experiencing a smell by now because there's no smell at all?

Best regards - Avenue

plumb1_2

You have a leak on your lead service pipe, it will not be any drain leaking. The best way to try and find the position of the leak, is to do this late at night, as the pressure will be highest. Turn the stop tap off in your house, if you can still hear it? then shut the stop tap off in the street/path/bounder then listern again. You can get a metal rod or a piece of timber, put a screwdriver on the end and stick your ear againt it, do this in several places and it will give you a rough idea were the leak is.