earthing insulated raft foundations

[jamieled]

I have an insulated raft and we don't have this. This thread is the first time I've ever heard of the possibility.

[saveasteading]

On 13/04/2022 at 16:50, Highland build said:

to attach to the reinforcement mesh to earth the slab?

 

Either this is nonsense or I have to worry about 50,000m2 of reinforced slab built without earthing, and the nation must have millions of m2.

Even where a cautious client has insisted on lightning conduction, this has not been linked to the floor reinforcement.

 

The only reason for doing this would be to complete a faraday cage.

 

There is a nice business in lightning conduction.  If you ask a lightning consultant they 100% tell you to get them to install a conductor system, which they can do for you.

If you don't ask, then seldom will anybody else ask for it.

(this does not apply to nuclear power stations and hospitals, where extra caution is sensible)

 

After thorough research I am still to find any example of death by lightning from a steel building or from reinforced concrete.

 

If it does worry you , why not just bang a steel rod (no need for copper) into the ground and tie it to the mesh?

This is increasing the ease of lightning rising through your building though, so I wouldn't.

[TonyT]

Forget about this in insulated slabs 

 

its used for other reasons generally not domestic so everyone can relax.

[Dreadnaught]

Tangentially related to this is I read that one of the effective ways to guard against PEN faults on an EV charger is to use the piles of a raft foundation (which are connected to the steel rebar and mesh of the raft itself) as the earth. I might do this.

 

It is superior to using any earthing mat to achieve an earth resistance way below 2.2.Ω, as required.

[Highland build]

ok thanks everyone i think i'll just forget i ever read about it!

[Highland build]

now does anyone want to comment on whether they used top hats around their services to seal their DPM 🙄 now that the eathings been ticked off the list of worries thats next on the list😆 yep i am at the you have to be insane to build a house and i'm only on week three🙈

[Highland build]

[Highland build]

This is where we're at just now. Water and electricity being connected next week and the insulated raft being put together head is spinning but I guess that's building a house and will probably continue for the next 6 months ahhhh so yea I'm not loosing sleep about earthing clamps and tape any more! 

[SuperJohnG]

22 minutes ago, Highland build said:

now does anyone want to comment on whether they used top hats around their services to seal their DPM 🙄 now that the eathings been ticked off the list of worries thats next on the list😆 yep i am at the you have to be insane to build a house and i'm only on week three🙈

I used some and they were OK on 110mm pipes but not essential..