Gas feed pipe questions

MouldyOldDough

We are getting work started on an extension today...

The building is a wet room - with toilet on the side of the house

The gas meter is by the  extension with the feed pipe across the lawn (hopefully just missing the foundations - however the toilet waste pipe will somehow need to cross the gas pipe

I understand that no building work is permitted over the gas pipe - so how will the toilet waste pipe reach the sewers ?

FreeBear

The foul sewer and the gas pipe are both "services", and not "building" - Perfectly reasonable for them to cross over as neither will be carrying any weight that would affect the other.

If you go out in to the street, you will find gas, water, electricity, and sewers crossing over/under each other without issue.

Eldi_Dos

Depending on the depth of gas pipe and run of new sewer pipe it may go under gas pipe rather than above.

MouldyOldDough

What about foundations over the gas feed? 

grumbler

MouldyOldDough said:

What about foundations over the gas feed? 

Is this pipe for you house only? Most likely it will have to pass through the foundation. And if it's some old steel pipe, it's a good opportunity to replace it with a modern plastic one - at least unaccessible part under the extension.
Alternatively it's worth considering  moving the meter to a new place.

MouldyOldDough

grumbler said:

MouldyOldDough said:

What about foundations over the gas feed? 

Is this pipe for you house only? Most likely it will have to pass through the foundation. And if it's some old steel pipe, it's a good opportunity to replace it with a modern plastic one - at least unaccessible part under the extension.
Alternatively it's worth considering  moving the meter to a new place.

Just our house
And its already been replaced with a yellow hose 

MouldyOldDough

Does it matter that the old steel now defunct gas pipe has been encased in concrete?
It's only been replaced from a distance of 2 metres from the meter - not the whole length 
Won't it rust and leak and when it does - it's going to be impossible to get to? 

FreeBear

MouldyOldDough said:

Does it matter that the old steel gas pipe has been encased in concrete?
It's only been replaced from a distance of 2 metres from the meter - not the whole length 
Won't it rust and leak and when it does - it's going to be impossible to get to? 

Current practice is to sleeve gas pipe where it goes through a wall. The sleeve bore should be 3-5mm larger than the gas pipe, and of an impermeable material.

A steel or iron pipe in concrete will slowly corrode, and as it does, it will expand and cause the concrete to crack. To a certain extent, the high PH level of the cement will provide a thin passive coating to the steel/iron which will slow corrosion to a very low level. But it is still "best practice" to sleeve the pipe so that it can be removed should the need ever arise.

Had an old malleable iron gas pipe under a concrete floor in my extension. Caught whiff of a slow gas leak, and the gas board came out, dug up the road, and disconnected the pipe at the main. No attempt to repair or replace the pipe was made.

grumbler

MouldyOldDough said:

Does it matter that the old steel gas pipe has been encased in concrete?

I think any pipe passing through a foundation is better to be boxed with some space around the pipe for small relative movement of the soil and foundation.

It's only been replaced from a distance of 2 metres from the meter - not the whole length. Won't it rust and leak and when it does - it's going to be impossible to get to?

It will eventually. Personally, I'd never leave a steel pipe inaccessible under concrete floor. Possibly event a plastic one. That's why I suggested finding a new place for the meter or rerouting the pipe around the extension.

MouldyOldDough

grumbler said:

MouldyOldDough said:

Does it matter that the old steel gas pipe has been encased in concrete?

I think any pipe passing through a foundation is better to be boxed with some space around the pipe for small relative movement of the soil and foundation.

It's only been replaced from a distance of 2 metres from the meter - not the whole length. Won't it rust and leak and when it does - it's going to be impossible to get to?

It will eventually. Personally, I'd never leave a steel pipe inaccessible under concrete floor. Possibly event a plastic one. That's why I suggested finding a new place for the meter or rerouting the pipe around the extension.

Too late !