Skimming over painted walls?

[Miles Reading]

Hi

The walls in our house have all been finished with a texture that looks like paint runs which cannot be sanded off easily so I was considering skimming over the walls.

What do I need to do to prepare the walls for the skim coat, I take it I will need something to allow the plaster to stick to the paint?

Many thanks

[Andrew Gabriel]

You should first go over the wall with something to remove any excessive high points. Hopefully you'll be left with a relief of no more than a few mm. You can PVA the walls to make the plaster stick, providing the existing surface is not coming away; pain the wall with 1:3 dilution of PVA and wait until it is almost dry before starting to plaster (if surface is very absorbent, preceed this with a 1:5 coat to soak in and dry, sealing the surface). First skim coat brings the surface up to the same level as the high points. Second skim coat should completely cover these and thus can be polished.