Grounding advice on older property

[Stubby]

Hi, I’ve just been to look at a job to add a socket in a ex-mod (1960ish) domestic property. The cables are singles pulled through metal conduit in between the ground and first floor. The problem is that the sockets have no CPC conductor in the back box so I ‘assumed’ that the CPC was fed through the metal conduit. I went back to the Consumer Unit to check this and the only earth that I could see was from the gas meter to the CCU. At this point alarm bells started ringing that the property is not grounded! I then thought that it maybe a TT system but there doesn’t seem to be a ground spike anywhere around the property. Could there be an ‘internal’ spike when the house was built?
I’m surprised as the CCU has been changed and smart meters have been fitted to this property so I’m beginning to doubt myself that they spotted something that I haven’t... any help would be great as I’m starting to think that this property isn’t safe.
Thanks in advance,

 

[Strima]

I'm slightly unsure how to do a Ze measurement if I don't know where the incoming earth is (if there is an incoming earth!) Do you have any pointers?

On the DB earth bar. There may be no main earth in the DB but a results would give you an idea of any possible earthing arrangement to look for and if indeed the installation is earthed.

 

[Deleted member 26818]

Looks like there might have been something attached to the incoming supply.
Move the hoover out the way so we can see the cable.

 

[Jim_e_Jib]

It's hard to make out behind the Dyson but the incomer looks like it could be PILC which would suggest originally a TN-S?

 

[Rpa07]

Yes the Dyson sure does not help - as all Dysons don’t. You’ll get a good 12 ohms through that gas pipe anyhow!

 

[Stubby]

So heres an update..... I contacted the DNO and they confirmed that there was no grounding to the property. they are coming back next week to confirm that there is a PME and then leave me to do the job of connecting the incoming CPC conductor to the rest of the house. thanks for your help everyone.