Earthing Rod ?

[spud1962]

I am just having a small kitchen extension built at the back of the house
which, naturally, requires a deep foundation. For the sake of an extra £10.00 and five minutes work, would it not be beneficial at this point to install an "earth rod" to supplement my existing installation (which i assume is already safely earthed).
If I do, should I connect the rod (for example) to my cooker, metal sink
unit, radiators & ring main which are already "cross bonded" and "grounded"?

My existing installation is "earthed" at the consumer unit which in turn is "connected" to the outer cable bringing in the supply to the house at the front.

In other words.. is it safe to have an electrical "earth" at 2 points in a house ?

 

[andy]

I am just having a small kitchen extension built at the back of the house
which, naturally, requires a deep foundation. For the sake of an extra £10.00 and five minutes work, would it not be beneficial at this point to install an "earth rod" to supplement my existing installation (which i assume is already safely earthed).
If I do, should I connect the rod (for example) to my cooker, metal sink
unit, radiators & ring main which are already "cross bonded" and "grounded"?

My existing installation is "earthed" at the consumer unit which in turn is "connected" to the outer cable bringing in the supply to the house at the front.

In other words.. is it safe to have an electrical "earth" at 2 points in a house ?

why bother. you have TNS which has a good earth path. better than your rod would have

 

[mapj1]

which i assume is already safely earthed

probably better to confirm that first. A rod will have 20-100 ohms of reistanec to true ground, If as andrew suggests you have TNS this will have a company earth of a fraction of an ohm. Addin perhaps 50 ohms in paralell with this will do very little.
More to the point, if youare worried about the safety of your earthing to
a) confirm the existing earth is TNC or TNS,
b) confirm the X bonding is up to scratch, clean and shiny and 10mm sq cable or fatter
c) Check the earth impedance - a competent spark should be able to do that in 5 mins, or you can hire the test gear, which essentially injects a short burst of L-E current to fake a fault condition and measures the step in L-E voltage it causes.

 

[spud1962]

thanks for the replies !