First fix cabling on celotex

[daunker]

I've 50mm celotex below purlins and then resilient bars running perpendicular over top. First fix electrics going in, and boarding this week. Electricians used some aluminium insulation tape to pin cables up (and some straps where were joists).

 

The insulation tape has let cables dropped, is it literally just to hold them up temporarily until PB is fixed, and then cables at future point drop onto pb as tape fails or should I attach a little better with something. I did half wonder about those insulation clips for ufh pipes. But if only needs to hold extremely temporarily until PB is fixed I'll just pop a bit more tape on.

 

Will ask electricians too but wasn't here when they were working, and would value a second opinion.

 

Thanks!

 

Edited Sunday at 20:27 by daunker

[nod]

Cables normally go in before the installation This is one I was installing last week 

[Nickfromwales]

Not great if your foil surface is the VCL?

 

Normal gaffa tape would have been better vs using flimsy foil tape for fixing them…..

 

But as above, cables should have been behind and pulled in whilst the insulation was installed. 
 

What lights are going in, as you’ll need recessed pockets in the insulation for spotlights?

[nod]

25 minutes ago, Nickfromwales said:

Not great if your foil surface is the VCL?

 

Normal gaffa tape would have been better vs using flimsy foil tape for fixing them…..

 

But as above, cables should have been behind and pulled in whilst the insulation was installed. 
 

What lights are going in, as you’ll need recessed pockets in the insulation for spotlights?

Great minds 😁

[daunker]

Thought cables aren't allowed to go with insulation surrounding them? There is another 215mm rockwool insulation between purlins. 

 

Lights are surface mounted spots to avoid having to chase out the celotex.

 

There is not an additional VCL. I'm sure I'd read @nod say elsewhere he didn't particularly like VCL on ceilings as when he was taking old ones down was moisture? Was some months ago so can't remember detail. The celotex is foil faced both sides and 50mm so I don't see it's that heavily compromised as VCL.

 

I'll pop some gaffa tape up instead. Thanks for input

Edited Sunday at 22:01 by daunker

[nod]

5 minutes ago, daunker said:

Thought cables aren't allowed to go with insulation surrounding them? There is another 215mm rockwool insulation between purlins. 

 

Lights are surface mounted spots to avoid having to chase out the celotex.

 

There is not an additional VCL. I'm sure I'd read @nod say elsewhere he didn't particularly like VCL on ceilings as when he was taking old ones down was moisture issue with the PB? The celotex is foil faced both sides and 50mm so I don't see it's that heavily compromised as VCL.

 

I'll pop some gaffa tape up instead. Thanks for input

Don’t forget to put pattresses in for each light smokes etc 

[daunker]

Thanks so much @nod, Sparkie said for me to just pull cables through. And I thought I could then pb the lot. Sounds like I was about to get unstuck. By pattress do you mean ply or something else above the pb for each fitting to screw into and distribute weight of light fitting/smoke?

 

Id rather assumed (sounds like incorrectly!) could just fix to PB as would only be lightweight

Edited Sunday at 22:12 by daunker

[Nickfromwales]

17 minutes ago, daunker said:

could just fix to PB as would only be lightweight

You can use some of the corkscrew type fixings tbh, but not just screws into PB ideally, but I have done it a good many times and just put a screw in every hole on a smoke head (about 7 screws) to be "safe". Only time you'll be caught out is if you're heavy handed swapping one out.

[daunker]

Thanks both so appreciate the replies.

[nod]

8 hours ago, daunker said:

Thanks so much @nod, Sparkie said for me to just pull cables through. And I thought I could then pb the lot. Sounds like I was about to get unstuck. By pattress do you mean ply or something else above the pb for each fitting to screw into and distribute weight of light fitting/smoke?

 

Id rather assumed (sounds like incorrectly!) could just fix to PB as would only be lightweight

Just cut a hole in a piece 400x400  ply or floorboard and slip over each cable and tack to the insulation 

Better to have and not need Fixing directly to pb rarely stay fixed 

[ProDave]

Cables should not be supported just by the plasterboard (and temporary tape to keep them in place until PB is fixed) they are supposed to be fixed in place so they won't fall down if the plasterboard collapses.

 

This follows incidents of firefighters getting entangled in cables after a ceiling comes down.

[daunker]

3 hours ago, ProDave said:

Cables should not be supported just by the plasterboard (and temporary tape to keep them in place until PB is fixed) they are supposed to be fixed in place so they won't fall down if the plasterboard collapses.

 

This follows incidents of firefighters getting entangled in cables after a ceiling comes down.

That makes sense, they are fixed with straps on purlins but the spacings are 600mm, so intermediate or where light fitting goes and cable dangles they had used tape.