Will plaster key to expanded foam

[Kev]

I have made a deep chasing into a wall to take 2 copper pipes for CH. If I fill this with expanded foam will plaster stick to the foam. I had thought about putting plaster board over the void and filling with foam as a backing for support but I might be able to dispense with the PB.

Kevin

[George]

No it wont,why put PB over the void? why not just slap the plaster in there when you're plastering it?

[Kev]

I didn't think that cement direct to copper pipe was acceptable so I am guessing that plaster direct onto copper might be frowned upon, plus the amount of plaster it would take.

Kevin

[Phil L]

plaster will stick to expanded foam, but it's a pain in the arse, if the chasing is deep enough, cover the two pipes with fibreglass insulation and plaster over - the pipes will have room to expand and contract and the plastering will be easier. Failing that, it's ex-foam *then* strips of plasterboard set into it, then plaster.

[TMC]

for metal lathing

Tony

[TMC]

Or more precisely Expamet Exmet on page 17