Hi,

Our consumer unit is on an external wall in the downstairs toilet
above the window and is very draughty, which makes the room cold in
the winter. I want to seal it up to prevent any draught's coming
through.

I was thinking of boxing it in draught sealing it (with a door for
access), but the missus' step-father suggested taking the front off
the CU and squirting some expanding foam in the void behind it to seal
it all up from there. It'd be much less hassle to do this.

Is this an ok thing to do? I've read that expanding foam can be
corrosive to cable insulation!? Not sure if it's an urban myth or not.

Thanks,

Jon