Finding out about utility cables/pipes before we dig?

[fex10]

The engineer that's designing the foundation for our new garage has mentioned that we should check if there's any water, electricity, or fibre in the ground before we dig. Seems prudent, but I think that any third party cables/pipes would have come up on the searches when we bought the house?

This engineer is in fact a commercial engineer who designs piles etc for large structures. He's doing our foundation design as a favour and he's never done anything domestic before, so maybe this isn't standard practice.

Who do we actually call? Thames water, sure. But there must be dozens of electricity companies, or is there a national one that is responsible for all cables? He also mentioned fibre... who do we contact to see if there's any fibre cables?

I do recall that the solicitor checked if there's any third party cables on our land when we bough the house so maybe this is not necessary?

 

[noseall]

Forget ringing any companies in regard to services locations, you will not get a definitive answer.

All you will get is "yes there is stuff there but as for exact location and depth" blah, blah.

Your best bet is a common sense approach and a bit of straight line planning. Look at where the water gas and electric first appear in your building and work back from there. However, there are no guarantees that the services follow straight lines.

It's not uncommon for services to share a trench.

You could get the property scanned (at a cost) or hire the equipment and do it yourself.

If you do damage a fibre optic cable be prepared for an extension on your mortgage!

What you do need is a sympathetic and careful digger driver.

 

[cjard]

What you do need is a sympathetic and careful digger driver.

"Sympathetic and careful" might be a synonym for "well insured"


You'd hope that services would have marker tape at the regulation distance above where they are laid

 

[OwainDIYer]

See this thread
//www.diynot.com/forums/buildi...f-services-for-water-gas-and-electric.360763/

Also for BT which wasn't mentioned
http://www.openreach.co.uk/orpg/hom...damage/protectingnetwork/networkprotection.do

 

[noseall]

It helps if you know where the services are but doesn't count for much when you are digging unless the guy on the digger is well versed and is liable for his actions.

A lot of digger drivers will put the onus onto the owner or else they say i'm off!

You are constantly looking for ground condition changes and looking to see how the material is being pulled out the trench. You look for tell tale signs like when the ground around your bucket starts to rise or when there is more resistance than usual.

A digger bucket is a brutal piece of kit but does require a bit of finesse. It is so easy to break stuff that you are constantly on your toes when digging on domestic jobs.

Always have a banksman looking in too.

Always make sure the road stop-cock is in working order.

All services i.e. gas, electric, sewer and water can be repaired. Fibre optic can not and costs £££'s. We often repair water and drains and we know guys who will do gas and leccy. If you hit a plastic gas service just crimp it over. The gas guys just use a clamp.

 

[ban-all-sheds]

we know guys who will do gas and leccy.

Yes - they are called National Grid and "the DNO for this area".

If you hit a plastic gas service just crimp it over.

That does not sound like a good idea.

 

[cjard]

In preference to leaving it open and pumping gas you mean?

 

[ban-all-sheds]

Err... no.

Not preference to calling National Grid because you "know guys who will do gas".

 

[cjard]

Oh.. I wasn't assuming that crimping the end over was the final fix - should have made that clear

 

[noseall]

If you hit a plastic gas service just crimp it over.

That does not sound like a good idea.

Small bore gas is not that big a deal. When you watch the gas boys working on it you will see what I mean.

The gas pipe itself is designed to be compressed and the gas boys use a simple screw clamp to stifle the flow of gas. My own fix-it man showed me the crimp thing whereby you fold the pipe over then tape it to stifle the gas.

Watching the boys work on a live electrical service is even more astonishing.

Incidentally all the boys I use are company guys. I'm just in a better position than the average diy'er.