Another earth bonding question

[Jim]

Still sorting out my earth bonding for the boiler.!

I've run the earth cable from the CU in our hallway to the gas meter under the stairs. The out pipe from the gas meter then goes down into the concrete floor and resurfaces in the kitchen. So am I ok to

a)just put a bond between the gas pipe in the kitchen and the water mains or b)should I really continue the same cable from the out pipe on the gas meter through half the house to the water mains ?

Obviously method a) is easier and personally I can't see it would make a difference what way I do it as to break the connection using method a) would involve digging up the floor to cut the pipe, but I'm guessing the regs wouldn't see it that way. If I'm going to the trouble of doing the bonding I might as well do it right. Can someone confirm for me.

Thanks

Jim

[John White]

I assume that we are talking about the main earth bonding conductors here. In which case:

Option a) would, as you suspect, not comply with the regs. Having the gas pipe as part of the circuit is definitely not allowed on several counts.

Turning to option b), there should be no joints in the main earth bonding conductors if possible. Where joints are unavoidable a proper connector (such as an earth commoning block) must be used. Putting a second clamp next to the first one will certainly not be satisfactory.

So you will ideally need to run another piece of 10mm Earth cable from the main earth terminal (near your consumer unit) to the main water stop tap in your kitchen.

It is usual to put the earth clamps on the water pipe a few inches on the house side of the stop tap, and a few inches on the house side of the meter for the gas. Don't forget to slip the warning label over the conductor before you attach it to the clamp.

Then, "to do it right" as you suggest, you just need to inspect and test the bonding before filling in a "Minor Works Certificate" for the work. Then, of course, there's the requirements of "Part P" to consider. ;-)

John

[Jim]

Thanks John

It's as I suspected, fortunately with the regs in mind I haven't actually cut the cable at the meter yet, just run the reel to there. So I can still carry on the cable run to the water mains as one continuous run.

Cheers

Jim

[ARWadsworth]

You can. Just remove the insulation where needed and make a loop to bond the gas and keep the cable uncut.

Adam

[John Rumm]

Note that you don't have to use the same bit of cable if it makes it harder. Two sepearate wires from the main earth terminal - one for gas and the other for water is also acceptable. They can even run outside the house if you prefer.

[Frank Erskine]

That's a point. If all I'm doing in the kitchen is renewing an earth bond to the water main, does that come under part P? Just out of interest - I don't really care ;-)

[ARWadsworth]

I guess it would not come under Part P if you are replacing a damaged cable on a like for like basis but changing from 6 to 10mm would be notifiable etc would be notifiable

Adam

[Peter Andrews]

Table 1 Page 8 of Part P says that:

"Work that need not be notified to building control bodies"

Work consisting of:

... installing or upgrading main or supplementary equipotential bonding.

Download the document at:

Peter

[Frank Erskine]

Thanks Peter.