Hole filling.

[jrh1]

Can I fill holes in ceilings and flooring, due to rewiring and plumbing, with expanding foam?

 

[vinn]

Your question is too vague.
Why not post pics of the holes in question?

 

[omega015]

Expanding foam doesn't sound suitable for this and could be messy and leave stains/residue on your ceiling. Are you not able to use some filler? If the holes are too big then you could pack the hole with some foam pieces or a bit of board/wood then use the filler.

 

[jrh1]

Filling the coving is easy enough, it's the gap beyond ,I'd like to fill as well.

 

[omega015]

I personally wouldn't use expanding foam anywhere near electrical cables as when they are curing they produce heat and not sure if they will also react with the PVC.

I would try fit a couple of pieces of small board into the hole with a bit of string glued to them (or pushed through a hole). Apply a little glue/silicone etc.. to the edge of the boards and using the string, pulling the board to the inside of the plaster. Once the boards are fixed into position, lightly fill in the edges and then the rest of the hole which should only be as thick as the plasterboard now. Take care not to make contact, nick, chip at those cables with your filler knife as you don't want to damage it

 

[vinn]

OP, you best bet is to remove all the filler from the chase - just lower than the wall surface - sand down the wall on either side for any remaining rough bits.
Assuming that you've used a metal channel and the run is in a safe zone then paste with a little PVA and water - wet down either side of the chase (it takes the suction up) and skim over pressing very hard as the stuff sets.

What about holes in the floor?

 

[John D v2.0]

Expanding foam won't damage the cables, it's polystyrene that has plasticisers that damage pvc cables. Although you would have to down rate the cables if you surround then with insulation.

 

[jrh1]

Was only looking at using a small amount to partially fill the void left by the missing ceiling underneath the coving.

 

[John D v2.0]

Go ahead then, won't damage the cables!
Even if it would, you can just wrap them. Eg. When you buy appliances in polystyrene, they just use a polythene bag to protect the flex. Although I used conduit when going through our external wall insulation.