Why Use an Earth Rod when a Disc will do?

I don’t disagree that knocking in rods comes with risks, but you still need to dig a hole three feet deep for the disc to get it down below frost point and that’s not risk free in an urban environment, if you dig a hole a couple of feet square and three feet deep that actually getting on for half a ton of soil that needs to be dug out and reinstated, without taking up and relaying any paving.

The discs are designed to fit onto the base of a telegraph pole in a hole that will normally be drilled into the ground with a very large auger mounted on a purpose built pole wagon, that hardly comes without an element of risk.

Sparkingchip said:

I don’t disagree that knocking in rods comes with risks, but you still need to dig a hole three feet deep for the disc to get it down below frost point and that’s not risk free in an urban environment, if you dig a hole a couple of feet square and three feet deep that actually getting on for half a ton of soil that needs to be dug out and reinstated, without taking up and relaying any paving.

Agreed ... but the issue is you can hand-dig the hole with an insulated spade. I think the fact this is a safer option is corroborated by the companies that do 1000s of these jobs.

Sparkingchip said:

The discs are designed to fit onto the base of a telegraph pole in a hole that will normally be drilled into the ground with a very large auger mounted on a purpose built pole wagon, that hardly comes without an element of risk.

Agreed ... but the discs are also easier to fit in existing situations where "banging in a rod" is fraught with H&S risks in the UK. Again, speak to the companies that install 100s or 1000s of these.

you could hand dig with  a plastic spade, and then drop in a  normal electrode and be richer ;-)

mapj1 said:

you could hand dig with  a plastic spade, and then drop in a  normal electrode and be richer ;-)

Well ... all joking aside, no!

To achieve same earth electrode resistance would likely require say 3 rods in triangle formation, perhaps 2-3 m deep, and therefore a triangular hole at least 2 m each side, and at least 2 m deep ?

Which is why I think a 600 mm square mat buried 600 mm deep is probably going to be the cheapest option overall, and most-often achievable?

Agree if we are burying a mat. But the condudisk seems to be quite high Z for what it is.  My point was not a joke though, if you are going to bother with the trouble of digging a hole to bury something, there are better things to put in that hole both in terms of cost and electrode resistance.The biggest advantage of that disc is lost if you do not already have a disk shaped hole anyway as part of other works.

Mike.

Agree if we are burying a mat. But the condudisk seems to be quite high Z for what it is.  My point was not a joke though, if you are going to bother with the trouble of digging a hole to bury something, there are better things to put in that hole both in terms of cost and electrode resistance.The biggest advantage of that disc is lost if you do not already have a disk shaped hole anyway as part of other works.

Mike.