bonding

[Baker1988]

hi every one this may seem like a bit of a daft question but i am unsure of the answer do we have to bond the water and gas mains when they come into the house i always thought you did have to but i have been reading thing on this forum and different people are saying different things so do we have to bond to water and gas? is it in the regs sayin we absolutly have to or is it good practice

 

[johnboy6083]

you have to bond any extraneous metalwork that enters your installation.
Extraneous means that it introduces a potential into the installation, generaly earth potential.
This could be water pipes, oil pipes, gas pipes, structural steelwork, the list goes on. One simple way of testing to see if it requires bonding is to test between the main earthing terminal and the item being tested. If the resitance is above 23Kohms, then it does not require bonding. If its lower than that, then it requires bonding.
Bonding should be installed as close as practicallly possible to the entry point of the extraneous metalwork, and before any branmches are made from it. 600mm away from the point of entry is listed in BS7671 as the maximum distance away from the point of entry, however if you cant access it to bond, then its acceptable to have this further away.

 

[Baker1988]

Thank you that has made it much clear for me I was really confused about it thank you

 

[trev]

The gas guys will kick off if you're 601mm away from point of entry but that's because they don't bother to cross reference their regs to ours or see the words "reasonably practicable"