Wiring up an icf house

[Russell griffiths]

I’m just about to start first fix wiring and looking for wisdom on how people ran wires when on an polystyrene icf wall. 

 

Im fully aware of the need to separate the wires away from the polystyrene, wondering what people have done to keep the separation. 

 

Im meeting the electrician later in the week and we have a number of ideas kicking about, but I thought it would be good to see what others have done. 

 

The ideas range from cutting a 25mm deep chase in the wall and lining it with foil tape, to installing a rectangular conduit the type with the clip on face. 

 

Any thoughts @willbish

[TonyT]

Bungalow?

2 storey?

suspended timber floor?

 

need more info for a solution.

[Vijay]

My future plans were conduit, maybe giving more chance of pulling a cable through if ever needed again

[Russell griffiths]

@TonyT the only area that is an issue is running cables on any of the icf surfaces. 

 

First floor is I joist so no problem there, ceiling has a service batten so no problem there it’s a couple of the icf walls will have switches or sockets but no service batten to create a void, so cables will need to go in the surface of the icf, so need a method of isolating them from the polystyrene. 

[Russell griffiths]

Just now, Vijay said:

My future plans were conduit, maybe giving more chance of pulling a cable through if ever needed again

Are you just thinking the 25mm round stuff. 

[TonyT]

Plastic conduit and adaptors into boxes

[willbish]

Nothing definitive yet @Russell griffiths. I wish I was that far along, Im still waiting for my plumbing schematic ?

 

Are you sure separation is required if you are using low smoke cables? I know these are different to standard PVC cable but I haven't done the research yet.

 

Im not sure if tape in the chase would stay put long enough...

 

[Pete]

3 hours ago, Russell griffiths said:

I’m just about to start first fix wiring and looking for wisdom on how people ran wires when on an polystyrene icf wall. 

 

Im fully aware of the need to separate the wires away from the polystyrene, wondering what people have done to keep the separation. 

 

Im meeting the electrician later in the week and we have a number of ideas kicking about, but I thought it would be good to see what others have done. 

 

The ideas range from cutting a 25mm deep chase in the wall and lining it with foil tape, to installing a rectangular conduit the type with the clip on face. 

 

Any thoughts @willbish

Just a tip. Have you decided on your switches as it can make a massive difference to your wiring? Only reason I am telling you is we wired traditionally as we had not decided on switches at this point. FF a couple of years and we decided to go with I lumos switches and they use a lot less wires so you can save quite a bit on sparky time. What I would say is the I lumos look lovely and when they work they are great but it is a steep learning curve wiring these switches but that is another story!!

[Vijay]

3 hours ago, Russell griffiths said:

Are you just thinking the 25mm round stuff. 

No I was thinking the capped stuff as you thought would be easiest

[Russell griffiths]

1 hour ago, willbish said:

Nothing definitive yet @Russell griffiths. I wish I was that far along, Im still waiting for my plumbing schematic ?

 

Are you sure separation is required if you are using low smoke cables? I know these are different to standard PVC cable but I haven't done the research yet.

 

Im not sure if tape in the chase would stay put long enough...

 

Don’t want to take the risk really, for the cost of a couple of lengths of conduit. 

 

[Adam2]

On 13/12/2020 at 16:47, Russell griffiths said:

it’s a couple of the icf walls will have switches or sockets but no service batten to create a void,

 

@Russell griffiths is it ok then to have the PVC cables near the EPS (so running within a 25mm void between EPS and plasterboard where they may touch the EPS), providing they are not embedded? Will make my life easier when I get to that stage

[Russell griffiths]

4 hours ago, Adam2 said:

 

@Russell griffiths is it ok then to have the PVC cables near the EPS (so running within a 25mm void between EPS and plasterboard where they may touch the EPS), providing they are not embedded? Will make my life easier when I get to that stage

I don’t know that’s why I asked, I have a lot of walls that will only have a light switch on, so I’m not going to batten the whole wall just for one switch, that’s the walls I was going to chase out. 

@willbish thinks the low smoke cable is ok in contact with the eps, if you look at any American vids they are still chasing the eps and pushing the cables in, but they are Americans ??‍♂️  

Im just trying to be careful so a 3m drop down from ceiling to switch I plan to fit conduit to be safe. 

[PeterW]

@Russell griffiths why not use Quinetic switches if it’s just for lights as you can put them wherever you want without cables. 

[Russell griffiths]

2 minutes ago, PeterW said:

@Russell griffiths why not use Quinetic switches if it’s just for lights as you can put them wherever you want without cables. 

It has been talked about. 

More discussions needed.  

[TonyT]

16 hours ago, Adam2 said:

 

@Russell griffiths is it ok then to have the PVC cables near the EPS (so running within a 25mm void between EPS and plasterboard where they may touch the EPS), providing they are not embedded? Will make my life easier when I get to that stage

no the polystyrene will attack the cabling.

cabling sheath will go sticky and cable starts to degrade. 

put cable in metal conduit drops to prevent cable touching 

 

or staple DPC to sheet and clip cable to sheet 

[Adam2]

OK cheers - will have a think about what to do then. Where I'm battening out I like the speed and low cost of the dpc idea, others will do like you then I guess Russell

 

[Stones]

On 08/01/2021 at 10:07, TonyT said:

 

 

or staple DPC to sheet and clip cable to sheet 

 

We used a similar approach (roofing membrane IIRC).