Skip to main content
Answer

I've found an old capped gas pipe in my house - Could it cause a leak if the pipe corrodes?

  • December 23, 2020
  • 4 replies
  • 7494 views
M
Carbon Cutter*****

I had a bit of time on my hands today (don't ask!) and I was wondering how long it would take for my old gas pipe to rust and cause a leak ?

It is hard to see in my pictures as it is in the background.

I am not even sure if there is gas in the pipe anymore although I think there is as why else would the pipe be turned off and capped ? 

The pipe was there when I moved into my house 25 years ago (I just paid off my mortgage 3 months ago)

I googled it and apparently old gas pipes were made of carbon steel that does rust although modern gas pipes are made of polyethylene (PE) 

Am I worrying over nothing as the gas pipe is embedded in concrete which would surely 'eat' into the carbon steel in the same way that it does to copper piping?

 

My water mains is made of copper and that runs under the foundation of my house and it doesn't have a protective sleeve to protect it but that's another story !

 

 

Best answer by Transparent

Updated on 08/09/25 by Abby_OVO

 

Worth mentioning that if you ever smell gas or are worried about a potential leak you should always call the national gas emergency line on 0800 111 999. Whilst our community volunteers are able to offer general advice any potentially hazardous gas pipework should be checked by a gas-safe engineer.

 

 

Ooh… a technical question. I just love these :hugging:

Judging from the construction style of the wall behind that capped-off gas pipe, I’ll suggest it’s a fair bit older than 25-years.

It’s probably either from the era when we had local gasometers to pressurize our gas pipes, or from the earlier days when towns made their own coal gas. Given your geographical location, @MikeE, I’m favouring the latter!

Chris Talbot / Salisbury - https://commons.wikimedia.org/wiki/File:Salisbury_-_Gasometer_-_geograph.org.uk_-_1037019.jpg

You need to consider what happened when that local distribution system was no longer needed. Each house had to be visited and have the old pipes isolated when the new supply was introduced. During the changeover period there would still be coal-gas in the old pipe, and if the tap was turned, it would poison everyone in the house.

Under the Gas Regulations at the time it was necessary not only to remove the old meter, but also to cap the pipe just above the isolator valve.

When the old coal-gas plant and/or gasometer was finally decommissioned, the larger pipes in the road were removed because the metal could be recycled. That left the small pipes on private properties remaining.

 

I doubt that your old gas pipe was capped at the other end when the main was removed from the road, so any residual gas would’ve long since disappeared.

Tim_OVO
Blastoise186

4 replies

Transparent
Carbon Catcher***
Forum|alt.badge.img+2
  • TransparentCarbon Catcher***
  • Carbon Catcher***
  • Answer
  • December 23, 2020

Updated on 08/09/25 by Abby_OVO

 

Worth mentioning that if you ever smell gas or are worried about a potential leak you should always call the national gas emergency line on 0800 111 999. Whilst our community volunteers are able to offer general advice any potentially hazardous gas pipework should be checked by a gas-safe engineer.

 

 

Ooh… a technical question. I just love these :hugging:

Judging from the construction style of the wall behind that capped-off gas pipe, I’ll suggest it’s a fair bit older than 25-years.

It’s probably either from the era when we had local gasometers to pressurize our gas pipes, or from the earlier days when towns made their own coal gas. Given your geographical location, @MikeE, I’m favouring the latter!

Chris Talbot / Salisbury - https://commons.wikimedia.org/wiki/File:Salisbury_-_Gasometer_-_geograph.org.uk_-_1037019.jpg

You need to consider what happened when that local distribution system was no longer needed. Each house had to be visited and have the old pipes isolated when the new supply was introduced. During the changeover period there would still be coal-gas in the old pipe, and if the tap was turned, it would poison everyone in the house.

Under the Gas Regulations at the time it was necessary not only to remove the old meter, but also to cap the pipe just above the isolator valve.

When the old coal-gas plant and/or gasometer was finally decommissioned, the larger pipes in the road were removed because the metal could be recycled. That left the small pipes on private properties remaining.

 

I doubt that your old gas pipe was capped at the other end when the main was removed from the road, so any residual gas would’ve long since disappeared.

Save energy... recycle electrons!
Tim_OVO
M
Blastoise186
G
New Member*
  • GassyPipe
  • New Member*
  • January 5, 2022

Hi. I just found this old thread on a search. Can I just drop in with a related query, that someone might be able to help with?

I have had an old water pipe burst below the concrete floor of one of my rooms, and it’s flooded the soil beneath, which is a kind of soil that holds moisture. I’m in a dragged out process to try and get it all replaced, as there’s no way it will dry of it’s own accord.

There is a metal gas pipe, 3cm diameter, steel or iron, which would have been fitted around 1960, currently trapped in this moisture-holding soil, which also has an unknown degree of sulfates present.

When a section of the concrete floor was dug up to repair the water pipe, the gas pipe was covered in yellowish water, a sign of rust/corrosion being present. I have dried off this section of the pipe as the hole is open.

The rest of the pipe, below the solid floor is currently inaccessible, and will be worse than what I saw in the hole.

Is there any rough idea on how long a pipe of this type and age would take to rust through to a point when there becomes a real danger of a leak, when it’s permanently trapped in water? This is clean drinking water by the way, not waste or rain water. Thanks for any help.

Blastoise186
Plan Zero Hero
Forum|alt.badge.img+1
  • Blastoise186Plan Zero Hero
  • Plan Zero Hero
  • January 5, 2022

Howdy @GassyPipe ! Nice name :)

Welcome to the OVO Forum by the way. That’s a great question you got there. We can definitely try to give you our thoughts, but as I can’t think of anyone on here who is a Gas Safe Registered Engineer, we’re unable to make it official per se, hope that’s OK with you.

Could you show us some photos of the damage by any chance? A picture tells a thousand words and in a case like this, really helps a lot.

Personally though, I’m a bit concerned about the water slowly eating through that rusty pipe and those sulphates are another concern. It’s unfortunately impossible to say how long that pipe will last until it fails, but I’d probably lean on the side of caution and consider whether to have it replaced sooner rather than later.

Securing energy by zapping security bugs... For that is The Blastoise Way! Remember, I'm just like you - AI Powered Evil Geniuses aren't Staff!
Jess_OVO
Jess_OVO
Retired Moderator
  • Jess_OVO
  • Retired Moderator
  • January 5, 2022

:point_up: Once again our community volunteer, @Blastoise186 has offered some tip-top advice!

 

Worth re-iterating the disclaimer given in the Best Answer above on this one:

 

Updated on 2/12/21 by Jess_OVO

 

Worth mentioning that if you ever smell gas or are worried about a potential leak you should always call the national gas emergency line on 0800 111 999. Whilst our community volunteers are able to offer general advice any potentially hazardous gas pipework  should be checked by a gas-safe engineer.

 

Whilst we’re always happy to give advice here, with something that has the potential to cause a gas leak or other dangerous situation this might be best checked out by an expert! 

 

Keep us posted here - we’re always interested to hear the outcome of seeking professional advice! 

Powered by Re-knowable Energy!
Tim_OVO
Terms & ConditionsAccessibility statement