Finding underground gas pipe on own land

[Happy Valley]

Apologies if this has been asked before - newbie here.

 

We are demolishing an annex which has the gas meter and supply on it's outside wall. 

 

I am applying to Cadent Gas to move the meter but am having my own contractor to do the trench. 

 

The query: Is there a relatively easy way of finding out the run location of the gas pipe under the garden? 

 

Edit: we are not having gas at the new house.

 

 

Edited February 9, 2021 by Happy Valley

[Dave Jones]

if you dont need the gas have them disconnect it. Which they will do on the road

[Happy Valley]

3 hours ago, Dave Jones said:

if you dont need the gas have them disconnect it. Which they will do on the road

 

We need the connection for the existing house which has GCH. 

[Moonshine]

4 hours ago, Happy Valley said:

The query: Is there a relatively easy way of finding out the run location of the gas pipe under the garden? 

 

I have actually had good results with dowsing rods (e.g. bent bike spokes / metal coat hanger), fook knows how it works, but in my experience i seem to be able to find pipes with them.

Edited February 9, 2021 by Moonshine

[Bitpipe]

42 minutes ago, Happy Valley said:

 

We need the connection for the existing house which has GCH. 

 

If you're not having gas at the new build, where (& why) are you moving the meter to?

 

From my experience, when you are demolishing you need to get National Grid to decommission your meter and have your billing company collect it to close the account.

 

You are not allowed to mess with their supply to your meter, even if its on your land.

 

Ok, I didn't see your answer above.

 

If your supply pipes is metal then a CAT detector may find it. If it's plastic (mine was) the only way to find it with a Cat detector is to insert a sonde in the pipe which the detector picks up. But obviously this means removing the meter and putting the probe in their pipe which is a no-no, but is how national grid determined where to dig up the road at mine. Mains gas is actually relatively low pressure so they put a blob of black gunk at the meter end of the supply pipe until they located it in the street and properly capped it off there.

 

You probably need to carefully dig a trench by hand near where the pipe exits the meter / house until you find it and then try and determine where it goes.

 

I did this with my electricity supply (the CAT scanner was not terribly useful) and dug the jointing pit and trench to the new meter location which was in a kiosk). 

 

Question is whether they will agree to make a new joint on the original pipe to the new location (no idea), whether the existing pipe can be lifted and relaid in a new trench to the new location (assumes it's long enough) or whether they will want to run a new pipe from the street main to the house.

 

You'll need to provide the yellow perforated trunking for new pipe runs as they don't bury them unprotected anymore. Gas supply pipe is not that flexible so you need a pretty much straight run and any bends will need a very generous radius.

 

 

Edited February 9, 2021 by Bitpipe

[SteamyTea]

43 minutes ago, Moonshine said:

I have actually had good results with dowsing rods

Are you willing to get in a JCB and start digging after dowsing for gas pipes.

[Happy Valley]

Thanks for all the answers.

 

Yes I was coming to the conclusion that an investigative hole is required near the current meter to determine the direction of the pipe - the radius could be anywhere within 45 degrees but is about 30 meters to the adopted road. 

[Moonshine]

13 minutes ago, SteamyTea said:

Are you willing to get in a JCB and start digging after dowsing for gas pipes.

 

As long as the gas was isolated! ?

 

I 'found' two suspected runs of a gas pipe and elec cable coming into my house. I had the ground investigator go over the area with his CAT scanner and found the same.

 

I would want something more scientific for confirmation of 'finds'. I am a sceptic on these hippy things.

 

Edited February 9, 2021 by Moonshine

[Bitpipe]

3 minutes ago, Happy Valley said:

Thanks for all the answers.

 

Yes I was coming to the conclusion that an investigative hole is required near the current meter to determine the direction of the pipe - the radius could be anywhere within 45 degrees but is about 30 meters to the adopted road. 

 

That is the best way forward - kind of thing you can do yourself - start with a 1m2 excavation from the meter and you should not need to go super deep. https://www.hse.gov.uk/pipelines/faqs.htm#:~:text=A gas main should normally,mm in footpaths and highways.

 

Once you find it you just follow it along until you get to the road or the point where you will pivot to another supply trench.

 

Out of curiosity, what's the plan once you've exposed the existing pipe? Have Cadent Gas agreed to the plan and come back with a list of contestable and non contestable works? - Contestable means they're ok if you do it (e.g. digging a new trench) whereas non contestable means they will do it at their cost and charge you whatever they like!

 

 

 

 

 

[Happy Valley]

4 minutes ago, Bitpipe said:

 

That is the best way forward - kind of thing you can do yourself - start with a 1m2 excavation from the meter and you should not need to go super deep. https://www.hse.gov.uk/pipelines/faqs.htm#:~:text=A gas main should normally,mm in footpaths and highways.

 

Once you find it you just follow it along until you get to the road or the point where you will pivot to another supply trench.

 

Out of curiosity, what's the plan once you've exposed the existing pipe? Have Cadent Gas agreed to the plan and come back with a list of contestable and non contestable works? - Contestable means they're ok if you do it (e.g. digging a new trench) whereas non contestable means they will do it at their cost and charge you whatever they like!

 

 

 

 

 

 

Cadent surveyor turned up today unannounced - I was out!! They have said they will get their installation team to have a look before confirming the job. We had planned on our contractor digging the necessary holes to save on the Cadent prices!! 

[Happy Valley]

Well I lifted 3 flag stones, one by the meter to see the direction and dug in one closest to where I thought the connection might be which was furthest away from the meter. Electricity was just below the flag as was broadband. 

 

Had to dig a lot deeper but luckily I have found another pipe which I am presuming is the gas pipe.