Urgent problem locating bonding on large site

[cornburn]

I have to get some certs in order fairly sharpish and am having real trouble finding main bonding in a high school. I'm hoping someone could give me some pointers for this type of setup.

They have several boiler rooms round the school with gas entering and water coming up out of the ground in at least 20 places in big 5" pipe or similar. I have gained access to most of the cupboards where gas comes up out of the ground and followed it to the boilers, there's no bonding in between. Also have followed water coming in for at least a few metres on each pipe until it branches off to other pipes etc and can't find any bonding on those either.

In this sort of large setup would the bonding be done differently? I haven't been able to find any sort of an MET to look for anything going out but even then might not be able to follow the whole run to check where it's going. In any case surely there won't be 30 different 50mm bonds coming out of it running off to all the different incoming pipes around the school will there?

They've had lots of work done in the past and I'm not sure whether or not these other contractors will have bothered to check for bonding. If I did a small job in a room with no extraneous conductive parts I'm sure main bonding would still have to be checked. Would it be acceptable to measure resistance between a socket earth and something like a radiator in the room? It would take days to go around and check every incoming service so what would the NIC inspector expect you to do in this case? Spend 2 hours adding a spur then another 2 days finding gas pipes and confirming connections? Would you just check the area you're working in? I'm confused for this setup.

I have jobs that need certificating but not sure what to do about ticking the box on the cert to show bonding has been checked when I can't find any! In a large setup like this would you guys go off round the site looking for incoming services or just check the nearest water and gas pipes?

 

[Spudnik]

To be honest, if you cant find it, then you would have to assume it doesnt exist and report it.

 

[pevvers]

Spend 2 hours adding a spur then another 2 days finding gas pipes and confirming connections? Would you just check the area you're working in?

Technically, if you are to abide by regulation 131.8, then you should be checking the bonding BEFORE you do any additions or alterations...

 

[Des 56]

Quote
Spend 2 hours adding a spur then another 2 days finding gas pipes and confirming connections? Would you just check the area you're working in? I'm confused for this setup.

In a nutshell,yes,if you agree to add to the existing installation and the protective measure requires it, thats what you price for

It is your responsibility before adding or altering to check these are present and adequate

Others may have not done so previously,but that matters not

 

[Deleted member 9648]

One very large school I work at was only bonded when we brought it to the attention of the local authority a few years ago....and last summer I did a PIR on a school which had had a lot of major work done by another contractor and the previous PIR by the same contractor.....no bonding to the gas (2 separate meters).
If you cant see it it probably isnt there......Ask site services/caretakers if there is a previous PIR or cert by another contractor you can refer to.

 

[Tester Steve]

They have several boiler rooms round the school with gas entering and water coming up out of the ground in at least 20 places in big 5" pipe or similar.

Then I would say you need at least 20 bonds. How many incoming supplies are there? As has been said, you need to know that the bonding is right before doing any work.

Steve.

 

[cornburn]

Thanks for all the replies. I know it should have been checked before I did anything but there was no one on site when I originally started work so couldn't get into cupboards to check. As they've had a lot of work done, a recent new build (£250k contract) and all the boards are only about 10 years old I assumed it must be ok. I can't see how all that work could have been done without bonding being in place. I've been looking for it at the point where pipes enter the building from outside, not at the meters. The meters are outside in separate buildings then the supplies come into the school from underground, so bonding at the meters themselves would be a waste of time.

With many boiler rooms etc in the school would you really check every single one to make sure they were all bonded? It really could take days checking for pipes in every outhouse etc the place is that big.

I'm going back tomorrow to have a good look round, any pointers would be greatly appreciated as the certs have to be in this week. The only PIR is about 12 years old and does mention lack of bonding at the time. Surely this must have been addressed since? I'm worried now as a couple of these jobs were being used for my NIC assessment and if it turns out there's no bonding that's going to be an instant FAIL!

 

[pevvers]

I would say that if there were many buildings, then checking of the bonding where you're installing the new work would be appropriate...

But if it's one big building, maybe just checking the services that supply the part you are working in?

 

[cornburn]

ok thanks Pevvers. It is one big building, but the meters are in separate outhouses. I guess checking the bonding of local services as you say is the only way to go. Where would you draw the line otherwise? Maybe taking some readings from earth to pipework would be a good way to start before spending ages hunting for the cable if it might not be there!