bonding soil pipe

[TicklyT]

Thinking about the jointing techniques that used to be found on cast iron soil pipe (sockets caulked with hemp and tar, pointed with mortar etc) does the pipe even qualify as a 'conductor'?

 

[bernardgreen]

Thinking about the jointing techniques that used to be found on cast iron soil pipe (sockets caulked with hemp and tar, pointed with mortar etc) does the pipe even qualify as a 'conductor'?

Worse case, the bottom bit of pipe is at ground potential. The next bit up is at the earth potential as supplied by the incoming PME neutral......
The joing id non conductive so there is a potential difference across the joint. And the pipe is venting a methane and air mixture from the sewers..........

On a radio transmitter site the metal soil pipe ( installed before the building became a transmitter site ) had to have each section bonded to the next section just in case there was spark across a joint. The radio frequency induced voltages were much higher than one would expect to find between domestic earth and ground.

 

[C&GStudent]

This is an interesting debate!

Can't you test resistance between the soil pipe and 'earth'? A certain value (I'm not sure what it is), will tell you if it needs bonding.

I can only see it needing main bonding. If it is insulated from earth it would need neither main nor supplementary bonding.

 

[plugwash]

but if its main bonded then it would also need to be supplementry bonded.

 

[C&GStudent]

Yeh sorry!

It's both or nothing.

 

[Mosez]

Yes if in a bathroom

surely if they are in contact with the ground they need to be main bonded not just supp bonded.

i tend to think a pair of clamps is probablly the easiest soloution though.

I agree, as well as supplementary it must also be Main bonded with 10mm2 cable if it is earthed Soil pipe.