An unfinished job needs finishing. A friend of mine has asked me to finish filling her big holes in her hallway, problem is someone else has already mainly filled the holes with some foam and White filler. Should I finish off the holes with more filler and then sand to a flat finish or can I use specific plaster on top of the filler for a smoother flatter finish? The filler that's already in the holes looks ok, it hasn't slumped or cracked but the holes with the foam in worry me as I've never seen this before.

Thanks for your help!

If its more than 5mm deep, use bonding plaster. then easifill. If its 2mm deep and less than 5mm, PVa and skim with multifinish. If it is 1mm or less, use easifill and sand.

Dig out the foam to half and inch and use PVA then bonding plaster for a robust fill, finishing with easifill.