Underground Leak Detection

[dougieunited]

Ok, so no sooner do I fix one problem, with advice from this forum, another one quickly follows it!

Anyways, I have a growing damp patch in the corner of my cellar that I believe may be the tell tale sign of an underground leak.

The corner where the damp patch is showing has the bathroom waste pipe, the toilet waste and the mains supply on the external side of the wall therefore I'm guessing that one of these could be the source???

Before I go digging up the front garden to investigate, I just wanted to ask if anyone is aware of any non-destructive methods that would possibly identify the source of any leak in that area?

Thanks for any advice

Neil

 

[alan999]

I am thinking that unless you can stop using each appliance for a few days and see if things dry out digging might be your best option. No doubt if you do identify the source of the leak you will have to start digging anyway to repair it so you might as well bite the bullet and have a look now.

 

[tamz]

Make sure no water in the house is running or better turn off at main stopcock. If you have a water meter check if it is turning which will indicate a leak. If not, put your ear against the valve or hold the shaft of a hammer (wooden one) and listen. If a burst main you will hear it running.

 

[Agile]

That last advice needs to be explained more fully!

You need to turn off an INSIDE stopcock if you have one.

THEN listed with a stick against an OUTSIDE stopcock if you have one.

There are drain dyes that you can put into wastes to track where they go. But unless you have enough to put into a cup you would not see the colour.

How deep is the damp place below ground?

How well defined is the damp place? Can you track it very accurately to any particular item outside?

A help might be obtained by drilling a hole perhaps 16 mm through the wall from cellar to outside ands see if you can get any running water which might help to track the source.

Tony

 

[Nige F]

All good answers - and cheap. If you eliminate mains incoming water as leaking - then look @ your drains . If plastic underground shouldn`t be them But if stoneware/ salt glazed, a real possibility Consider a CCTV survey , but it won`t be cheap .

 

[dougieunited]

Thanks for the responses. Tamz - I don't have a water meter so cannot use that method of checking, however I will try listening in the area.

Agile - in response to some of your questions. The damp patch is on the floor of the cellar, which is just under 2 metres below the surface. The patch appears to be extending from the location of the three pipes mentioned in my original post.

I have taken some photos that will probably better show what I'm trying to describe.

View media item 20678
View media item 20679
The pipe in the top right hand side of the pictures is the main supply pipe. The two waste pipes from the bathroom run on the external side of the wall.

The walls don't show any signs of being wet or damp other than the usual damp that would expect in cellar that hasn't been sealed.

Ta

Neil

 

[tamz]

What is behind that external corner? It wouldn't be a chimney would it?

 

[dougieunited]

No, no chimney in that corner. Basically it's just the external wall of the house and to the right hand side of the corner on the external side is where the bathroom waste pipes run.

Neil

 

[Agile]

Are you saying the external wall of the house really has that inverted corner on the outside?

That seems very unusual.

Tony

 

[dougieunited]

Yep, that corner is the right hand side of the bay window for the living room

Neil