Best electrical back box for ICF

[freshy]

Finally at first fix! Which electric back box you recommend for EPS/XPS ICF for plug sockets and light switches? Standard, plastic, steel or other? 

 

 

[JohnMo]

I did a 50mm service void, so just a big standard one for plasterboard.

[Chanmenie]

1 hour ago, freshy said:

Finally at first fix! Which electric back box you recommend for EPS/XPS ICF for plug sockets and light switches? Standard, plastic, steel or other? 

 

 

I used 35mm metal back boxes, my internal layer of EPS  is only 55mm ( Beco Wallform ) so I screwed the back boxes to the concrete 

[nod]

Cheapest

They all do the same thing 

[ProDave]

1 hour ago, nod said:

Cheapest

They all do the same thing 

Not if we are talking of plasterboard boxes.  Appleby every time for me.  Some of the others are complete rubbish.

[nod]

2 hours ago, ProDave said:

Not if we are talking of plasterboard boxes.  Appleby every time for me.  Some of the others are complete rubbish.

 

 I’m not sure why you would use plasterboard boxers There all pretty crap 

[Chanmenie]

1 minute ago, nod said:

 

 I’m not sure why you would use plasterboard boxers There all pretty crap 

Yeah I’d only use them for what they are designed for. Certainly not in ICF walls 

[Nick Laslett]

5 hours ago, freshy said:

Finally at first fix! Which electric back box you recommend for EPS/XPS ICF for plug sockets and light switches? Standard, plastic, steel or other? 

 

 

Talk to your electrician. How are you finishing the ICF, plasterboard on battens with service void, or direct fix to EPS? Do you know that you can’t run standard electrical cable in EPS, because the PVC jacket will perish over time. Standard 35mm deep steel back boxes fixed to the concrete work fine, but that does depend on how you are finishing the plasterboard. 

[freshy]

Thank you for your responses, I planning plasterboard directly on to the EPS hence I'm running electrical cable in conduit to protect it.

 

My internal ICF wall has 50mm and external has 100mm of EPS. Will speak to my electrician first, with a view of using standard 35mm metal boxes.

 

 

 

[Chanmenie]

1 hour ago, freshy said:

Thank you for your responses, I planning plasterboard directly on to the EPS hence I'm running electrical cable in conduit to protect it.

 

My internal ICF wall has 50mm and external has 100mm of EPS. Will speak to my electrician first, with a view of using standard 35mm metal boxes.

 

 

 

 

Chase out with an electric foam cutter 

https://hilltop-products.co.uk/tools-cutters-machinery/hot-knife-rope-cutters/hand-held-hot-knife-rope-cutters/hand-held-kd-7x-premium-hot-knife-foam-cutter-groover-kit-with-case-accessories-230v.html

 

[FM2015]

14 hours ago, freshy said:

Thank you for your responses, I planning plasterboard directly on to the EPS hence I'm running electrical cable in conduit to protect it.

 

My internal ICF wall has 50mm and external has 100mm of EPS. Will speak to my electrician first, with a view of using standard 35mm metal boxes.

 

 

 

 

Would recommend 47mm deep plasterboard boxes and all chases hot knifed and conduited between webs.  

[Tosh]

Similar to others we just used 35mm metal boxes, which work nice with 25mm batten and 12.5 pb, screwed to webs.

[BotusBuild]

On 13/05/2024 at 08:06, Chanmenie said:

Chase out with an electric foam cutter

Just about to do this myself. Using metal boxes with conduit running through the EPS (Nudura in my case) then an adapter to hold the conduit to the metal box.

 

The key thing is the cable must NOT touch the EPS.

[Nick Laslett]

45 minutes ago, BotusBuild said:

The key thing is the cable must NOT touch the EPS.

It is only PVC jacket cable that is a problem. LSOH/LSZH jackets do not contain PVC and will not react with EPS. The only cables I have that are not LSOH/LSZH is the special coms cable from Panasonic to add LAN to my ASHP. You can easily get electrical cable, speaker cable, hdmi cable, cat6 cable, etc with non-pvc jackets. 

[BotusBuild]

For transparency - LZOH/LSZH is about 20-25% more expensive on a quick internet search

[Chanmenie]

6 hours ago, BotusBuild said:

Just about to do this myself. Using metal boxes with conduit running through the EPS (Nudura in my case) then an adapter to hold the conduit to the metal box.

 

The key thing is the cable must NOT touch the EPS.

I fitted grommets in the boxes and used 25mm oval conduit, as per the electrician’s instructions