Not Bentonite the concrete stuff?

[Marvo]

When the OP mentioned concrete I thought he was contemplating using the foundations or slab of a building as an Ufer earth and not backfill for a rod. I think we're talking about two entirely different types of earth.

 

[Mr Hehound]

Sorry guys - my bad terminology. Meant the backfill cement / slurry stuff. Marconite as Eng 54 says.

Sorry for causing confusion.

 

[Engineer54]

When the OP mentioned concrete I thought he was contemplating using the foundations or slab of a building as an Ufer earth and not backfill for a rod. I think we're talking about two entirely different types of earth.

They actually call it Conductive concrete on the Furse web page, but it's really a mortar, as concrete is only concrete when it has ballast/stone in the mix!! But it is really good stuff, if you can bore the holes for it. You'd need a hell of a lot of it on your rod installations mind, the depth that you say you have to go down too!! lol!!

 

[Marvo]

We have something similar to bentonite around these parts but never used Marconite and never seen or heard of it being used here, we'd probably have to import it. I'd be interested in giving it a go if you fancy sending me a few bags on apro Only problem I can see is in the sand areas we'd probably need to get a odex rig on site to sleeve a hole then backfill with a rod and remove the sleeve.

Fingers crossed, most of the TT systems we've installed this year we haven't needed to go below about 10 meters and only needed a single rod. Pot luck really one last year we knocked an array of 8x 12meter rods and even with parallel paths from the foundation steel of the pumpstation we were still sat with >50ohms and had to resort to additional earth mats. The earthing ended up costing more than the control panel.