Using filler (expanding?) around an electrical socket

[acr]

I'm wallpapering a wall that was previously hidden behind fitted wardrobes. There is a socket with a recessed metal box that was presumably moved to the right to accommodate the wardrobes. I now have a large hole where the socket used to be that needs to be filled with polyfilla or whatever, but I'll be filling up to the metal box. I'm a little edgy about filling near electrics, so I'll play safe and will turn the power off to do this. However is there any risk in using expanding foam filler (near electrics) instead as the gap is quite large ?

 

[grahamderek]

Expanding foam can damage twin and earth cable.
You must keep them seperate.

 

[TonyWarrington]

After seeking advice via another thread and contacting manufacturers I believe that most expanding foams (polyurethane) are safe for electrical work.

Quote Voltimum -Only polystyrene thermal insulation is of serious concern for PVC sheathed cables. In general it is not required to place PVC sheathed cables in separate conduit if passed through polyurethane or polyisocyanurate thermal insulation. The thermal insulation polymers are different and do not have residual chemicals present that are found in polystyrene thermal insulation.

Quote Polycell -For electricity piping recommend using Polycell Trade Fire Retardant Expanding Foam

 

[ban-all-sheds]

What's wrong with just using plaster/Red Devil/Polyfilla?

 

[acr]

Nothing, other than drying time, and the gap is very large which requires building up in layers.

 

[Chri5]

Nothing, other than drying time, and the gap is very large which requires building up in layers.

Which is why you get a square or rectangle of plasterboard and pad the hole out 1st.

Saves on filler, saves on drying time and prevents any wet filler getting into contact with any wire behind the plasterboard.

 

[ban-all-sheds]

If you mix the first layer stiff enough you'll only need two in total.

Drying time is still an issue though.

I always look at it (DIYing) from the POV of how long it would take me to cut and fix a suitable bit of padding vs how long it would take to make a stiff mix and slap it in, 'cos I always seem to have something else I can be getting on with while it dries...