Help and Advice For New Installation In Celotex PL4065

[SMG]

Very good points, I had this issue last week where someone want me to fit a dimmer into a 25mm and it wouldn't fit.

Right, so 30mm wall spacers, gap in middle for cables to go from block work to back of boxes, 35mm back boxes!

I really appreciate all this guys you've been very helpful!

Unfortunately this isn't something I have encountered before and wanted some sound advice from people with experience.

 

[telectrix]

what i meant was run your cables directly behind the board, not on the blockwork. unless you can't get them in there.

 

[davesparks]

what i meant was run your cables directly behind the board, not on the blockwork. unless you can't get them in there.

Eh? The blockwork is directly behind the board. The insulation is glued to the plasterboard.

 

[telectrix]

Eh? The blockwork is directly behind the board. The insulation is glued to the plasterboard.

never seen that, dave. must be some modern thing.

 

[SMG]

what i meant was run your cables directly behind the board, not on the blockwork. unless you can't get them in there.

Ah I see, but wouldnt that mean I would have to chase out the celotex so the cables were 50mm deep from the surface of the wall?

The Cellotex site states:

[h=3]Can I recess electric cables into Celotex?[/h]No. Electrical cables should not be channelled into Celotex as that would reduce the performance of the Celotex.
Cables can penetrate through Celotex and if cables are laid between two layers of Celotex they should be oversized to cope with any increase in operating temperature.
Celotex has no detrimental effect on the cable sheathing.

This is why I was going to put the cables on the wall, however I am not the experienced one here and am open to advice.

 

[davesparks]

Unless I'm reading it wrong you have insulation backed plasterboard being stuck to the wall. So you have choice but to fix to the wall. Plus fixing cables to the blockwork will be best from a thermal point of view for the cable

 

[Leesparkykent]

Is it just dot and dabbed to the wall?

 

[GEOFF S]

Hello all,

First of all I would like to say if anyone comes here just to have a go because I'm not as experienced or knowledgeable as them etc.. then please do not comment just move along, I am here asking questions to learn not be belittled.

Now, I am a newly qualified electrician and have been asked to run the 1st fix for someone in a new house extension.

The drawing states:

Internal dry lining 65mm Celotex PL4065 + 12.5mm Plasterboard - Taped Joints.

To my understanding this will be most likely adhered to the new block work directly is this right?

Now do I fix the cables for the new ring main direct to the block work in an oval conduit, then instruct the guys installing the celotex to cut the insulation out around the cable ends where the PB boxes will go or is there another/better way to do it?

Any suggestions are welcome as long as they are constructive lol

Many thanks in advance

Hi

Is there a reason the isulation can not be places in the cavity? 65mm bonded celotex is carp form many reasons.

Cheers

 

[SMG]

Is it just dot and dabbed to the wall?

I do not know as I haven't spoken to the builders installing it, I can only assume it will be.

I have asked someone to find out for me so I know more.

I think with all of the points I have been given so far I have a good plan now, thank you all!

On a separate note...

Bathroom extractor fans with built in PIR (Xpelair DX100PIR Extract PIR Timer Fan Kit) I cant find any info on it but I am assuming these just need a supply taken from a local lighting circuit but with a permanent live rather than a S/Live (L/N/E)?

 

[SMG]

Hi

Is there a reason the isulation can not be places in the cavity? 65mm bonded celotex is carp form many reasons.

Cheers

Im not sure its just what it says on the drawing provided by the client.

I'll probably get there and it will be completely different knowing my luck lol

 

[Leesparkykent]

I do not know as I haven't spoken to the builders installing it, I can only assume it will be.

I have asked someone to find out for me so I know more.

I think with all of the points I have been given so far I have a good plan now, thank you all!

On a separate note...

Bathroom extractor fans with built in PIR (Xpelair DX100PIR Extract PIR Timer Fan Kit) I cant find any info on it but I am assuming these just need a supply taken from a local lighting circuit but with a permanent live rather than a S/Live (L/N/E)?

Yeah just LNE via a double pole switch or fused spur depending on what the MI say.

 

[Richard Burns]

DX100 PIR wiring diagrams, the PIR operates for a time period after sensing movement.
If it does have an override you need a SL and PL.