National Grid replacing gas mains
Discussion
Just had a letter from the nice people at National Grid, stating that they are going to be replacing the steel gas main with plastic, and that if our supply pipe is metal, then it will be replaced and the gas meter will be moved. Worst bit is that we're on a main commuter route, so the impact on rush-hour traffic is going to be, ermmmm, interesting to say the least.
Are they likely to dig a trench to do this or is is going to be moled, as if they are trenching it, I'll lay a new water main at the same time, kill two birds with one stone as it were.
Are they likely to dig a trench to do this or is is going to be moled, as if they are trenching it, I'll lay a new water main at the same time, kill two birds with one stone as it were.
They did it here last year, dug up the pavement that it ran under, they actually put the plastic where the metal pipe was. They were doing maybe 100 yards at a time. My feed is plastic anyway, I don't think anyone long this stretch had a metal feed.
When I had my feed put it 10+ years ago they moled it.
When I had my feed put it 10+ years ago they moled it.
Ours is still being done. We have had two big holes in the pavement covered in a metal plate for about 4 weeks now - our gateway, already fairly slender, is now about 4" wider than the car mirrors because of the plastic barriers to stop people falling into the holes. The contractors thread a new plastic pipe down the old cast iron main, but unfortunately the pipe jammed this week and they had to work nearly to midnight to dig up the narrow bit of main and sort out the houses affected. We've one plastic offshoot to the house (from when I had the meters consolidated into one, external one) and had one steel one (barely 6" below the surface of the drive) which had led to two other meters when the house was flats - that was still live.
Impressive that they can splice in just a few houses at a time - there are plenty of fire extinguishers about as it is being done.
Most houses have not had to have any digging within their boundaries - presumably the new plastic pipe has gone easily to the meter. If you want your meter moved (e.g. to an outside buried one) you can have it done for a fee, but it doesn't stop you getting irritating phone calls asking you to send your reading and estimated bills.
PS - I dug a trench for a new water main a few years ago - a (narrow) trench digging spade was very useful. Be careful to dig it deep enough - which is, ironically, well beneath the level of the existing pipes as the inspector will need to see that the water pipe is deep enough before they authorise filling in and connection. The neighbours opposite had someone dig them a trench - he did so (by hand), put the pipe in, and backfilled - the inspector made them reveal the pipe again to ensure it was deep enough before signing it off. The depth - which I can't remember now, is almost deep enough to withstand Siberian winters, which will be useful when the Gulf Stream stops flowing in a hundred years or so.
Impressive that they can splice in just a few houses at a time - there are plenty of fire extinguishers about as it is being done.
Most houses have not had to have any digging within their boundaries - presumably the new plastic pipe has gone easily to the meter. If you want your meter moved (e.g. to an outside buried one) you can have it done for a fee, but it doesn't stop you getting irritating phone calls asking you to send your reading and estimated bills.
PS - I dug a trench for a new water main a few years ago - a (narrow) trench digging spade was very useful. Be careful to dig it deep enough - which is, ironically, well beneath the level of the existing pipes as the inspector will need to see that the water pipe is deep enough before they authorise filling in and connection. The neighbours opposite had someone dig them a trench - he did so (by hand), put the pipe in, and backfilled - the inspector made them reveal the pipe again to ensure it was deep enough before signing it off. The depth - which I can't remember now, is almost deep enough to withstand Siberian winters, which will be useful when the Gulf Stream stops flowing in a hundred years or so.
Edited by Revisitph on Friday 12th July 20:32
R1 Indy said:
Do you men replacing lead piping rather than steel?
Don't see what the point of changing the steel piping is when there is still loads of properties still with lead..
There's a huge amount of cast iron gas main which is reaching the end of its design life. British Gas had agreed to replace it on a rolling programme since 1977, however in the late 90's (under the privatised business...) the replacement rate fell by approx. 50%. In early 2000s the HSE formally forced Transco to increase the rate to get back on track.Don't see what the point of changing the steel piping is when there is still loads of properties still with lead..
From http://www.hse.gov.uk/gas/domestic/gasmain.pdf
"There are about 91,000km of remaining iron mains within 30m of buildings (’at risk’ mains) which may give rise to a risk to people. The majority of these - some 78,000km - are cast iron mains, the remaining 13,000km being low pressure ductile iron mains (see Appendix 1). Each year these mains suffer about 23,000 fractures and corrosion failures leading to 600 ‘gas-in-building’ events causing on average 3 to 4 major incidents (fires and explosions) resulting in the deaths of 1 to 2 people
annually. However, each gas release incident has the potential - depending on location - to cause multiple fatalities: for example Putney (in 1985 - 8 fatalities), Rutherglen (in 1985 - 5 fatalities) and Larkhall (in 1999 - 4 fatalities)."
We had our house gas main done a few years ago and it was very straight forward. It reminded me of the time that I had a summer holiday job in the late 1960s with a road gang making a new road on a 1930s estate.
Gas and water pipes had already been replaced the previous week. We were digging at one point when there was a strong smell of gas. We had dug through what remained of the old pipe but there was no pipe left. The ground was clay and the pipe had rusted totally away with the gas passing through a tube in the clay about a foot below the surface. The clay was discoloured from the rust.
So those pipes lasted less than 30 years.
Gas and water pipes had already been replaced the previous week. We were digging at one point when there was a strong smell of gas. We had dug through what remained of the old pipe but there was no pipe left. The ground was clay and the pipe had rusted totally away with the gas passing through a tube in the clay about a foot below the surface. The clay was discoloured from the rust.
So those pipes lasted less than 30 years.
j3gme said:
Took this pic last year outside my house... I new it would come in useful ( what a boring life I have!)
ghamer said:
They'll put the plastic through the original metal service and it should come out the other end near the meter.They don,t always move the meter only if its impossible/tricky to renew to original position.
This is what they did for us earlier in the year, they only needed access to the house for 15 mins on two consecutive days. Everyone on the next street over had to have their drives/front garden dug up though.Gassing Station | Homes, Gardens and DIY | Top of Page | What's New | My Stuff