Conduit to kitchen island: how does it go through the concrete raft?

[Dreadnaught]

Basic question if I may. Anyone with an MBC-style raft will be able to answer in a flash I expect.

 

With an insulated reinforced concrete raft foundation (200mm concrete over EPS), how does a conduit run to a kitchen island (or, for example, to floor sockets in the sitting area) for electrical cabling?

 

Possible answer 1: does the conduit penetrate all the way through the raft and the EPS into the soil beneath, like a service penetration, and then re-emerge elsewhere in the build next to a wall?

 

Possible answer 2: does the conduit penetrate laterally throughs the raft spanning from a wall to the island without penetrating the EPS?

[Jeremy Harris]

I just ran 25mm electrical conduit through the slab like this, with gentle bends on either end to make it easier to pull the cables through:

 

 

Before the pour, the conduit was cable tied to the steel mesh to hold it in position.

[RandAbuild]

Don't forget about drainage & water if you're thinking about having a sink on the island too

[RandAbuild]

Here's ours

[Carrerahill]

27 minutes ago, Dreadnaught said:

Possible answer 1: does the conduit penetrate all the way through the raft and the EPS into the soil beneath, like a service penetration, and then re-emerge elsewhere in the build next to a wall?

 

 

It would not go through the lot to the soil no, it depends on makeup of your slab and all sorts but it could be encased in the concrete, the big house builders tend only to put the bare minimal in the slab like incoming utilities and drainage, then all the wiring and radiator pipes drops from the ceiling level, I don't like this way much but as an example it's what some do. There are so many ways to do this to be honest. 

[Dreadnaught]

20 minutes ago, RandAbuild said:

Here's ours

 

Oh, is that image in preparation for the pour of a screed?

Edited January 16, 2020 by Dreadnaught

[Dreadnaught]

32 minutes ago, Jeremy Harris said:

I just ran 25mm electrical conduit through the slab like this, with gentle bends on either end to make it easier to pull the cables through:

 

Thanks @Jeremy Harris. The other end seems to come up in your double-stud wall. Am I right? Why was that?

[Jeremy Harris]

4 minutes ago, Dreadnaught said:

 

Thanks @Jeremy Harris. The other end seems to come up in your double-stud wall. Am I right? Why was that?

 

 

The wall end of the conduit comes up inside the service void, just inside the twin stud wall, and the cables then run vertically up to the isolator switches on the wall above.

[RandAbuild]

8 minutes ago, Dreadnaught said:

 

Oh, is that image in preparation for the pour of a screed?

Yes, that's before the final screed. We did not have an MBC insulated slab though. Ours was a 'Jetfloor ' - insulated blocks between concrete beams, overlaid with EPS. The drainage was laid below the Jetfloor (as in a traditional block and beam), but the services were in the screed (including supply for our induction hob).

If you have a sink in your island, I presume your drainage would be the same as foul drains below the MBC slab?

[You can see we also added a gas supply in case we didn't like the induction hob (we do!)]

Edited January 16, 2020 by RandAbuild
Additional text added

[PeterW]

I use 32mm solvent weld pipe and a pair of 45 degree bends on each end.  Makes it easier to thread 10mm cable through as it can be very stiff. Bring it a fair bit higher than the slab and then just cap it off both ends so it doesn’t get filled with water or concrete. 

[Dreadnaught]

Thanks all. Makes sense.

 

Want to have floor sockets under the sofas for table lamps. That will need a conduit as you all describe. But what about a former in the concrete for the actual socket in the floor?