On Saturday, September 28, 2019 at 3:13:48 PM UTC+1, sm_jamieson wrote:
I have a plastic CU (installation according to regs in 2006 when plans were passed !), that I am just finishing - having changed to all RCBOs, etc.

Well if I did another CU I'd try to have cable entry in the back or bottom, but where it is that would be difficult anyway.

So I need to seal the cable entries at the top, which are cables going into square cutouts with a lot of gaps.

The best price for a smallish amount of intmescent putty I found is here (it seems to generally be quite expensive):
https://www.fireprotectionshop.co.uk...tty-310ml.html

I also thought of using intumenscent sealant and letting it dry a bit and using as a putty if that would work, i.e.
https://www.toolstation.com/fire-mat...t-310ml/p58145

I also thought of some type on intumescent foam that could be pushed in to all the gaps but I did not find anything suitable.

Any ideas ?
How is this usually done ?

Thanks,
Simon.

Oh, the other idea of course was ... expanding foam (intumescent) !
You can get fire-rated expanding foam, it that would do (might not actually expand with heat though so not truly intumescent).
The risk there is of putting in too much and wrecking the installation !

Simon.