Checking for mains coming into the house while digging.

[rjbell]

My new house has raised the ground level of the house and covered airbricks and the original DPC. I plan on digging this out back to ground level and put some drainage in. I'm worried i will put a spade through the mains wire coming in or pipe work or something. Would a live wire and pipe detector you would use for walls be sensitive enough to detect this?

Can i assume the electric will take a straight line along the boundary wall to the meter in the porch?

 

[bernardgreen]

Can i assume the electric will take a straight line along the boundary wall to the meter in the porch?

NO you cannot assume that !

A detector that is designed to find pipes or cables in wall will NOT detect an electric cable under ground. You can hire detectors that work to a metre deep but these are not 100% reliable.

Your DNO may have records of where the cable to your house runs.

 

[vv2806]

I agree with Bernard and know this from experience. The service cables to my house are not at a straight line along the boundary (we had them exposed and redirected by the DNO). My DNO (the Western Power Distribution) records were useless - the properties on the map were something like 2 x 3 cm shapes and the cables were just a line from the street to the house, not even in the corner where the real cables were. They were at about 1m depth and yes, we used a spade to dig the trench and even if we wanted, it would be very difficult to cut those cables. They were about an inch in diameter and had several layers, including some metal wrapping. While digging we exposed also the gas mains and the water mains, no damage to them either. Just don't jump on the spade.

 

[OwainDIYer]

Contact the DNO and they may have better plans or send someone out to scan and mark the site for you.

 

[aesmith]

Contact the DNO and they may have better plans or send someone out to scan and mark the site for you.

Exactly what we did. They sent scanned plans by email, then when that wasn't accurate enough the sent a guy to site with a CAT scanner, we went round together and he marked across the tracks of our planned trenches, also explained what the cable would look like if/when we found it.

 

[Guitarguy]

The best thing you can do is give the dno a call and arrange a cable trace to be done and the route marked out. It hopefully will be free.

Cable plans probably won't help as services are very rarely drawn in these days and most of the time not drawn on the plan anyway- only the main cables are shown usually. With an assumed line going to each house as a service.

If you are very lucky, old service cards may exist that date back to when the supply was installed if the house is old enough- our lot, sse (was s.e.b) stopped using these around 1990. And these have hand drawn diagrams of the service and joint locations.

As I said, don't hold your breath of finding one though

 

[rjbell]

OK thank you guys.

 

[ekmdgrf]

A detector that is designed to find pipes or cables in wall will NOT detect an electric cable under ground.

Nor will it detect pipes or cables in a wall.