Skim coats and re-skims
A skim is a 3–5mm finish of multi-finish plaster (typically British Gypsum Thistle MultiFinish) laid over a sound substrate. It's the right answer for tired but stable plaster, blown patches that have been cut out and made good, and walls that have been stripped of wallpaper down to bonding. We control suction with PVA or Blue Grit depending on the substrate, scrim-tape any joints or cracks, fit metal beads to corners and reveals, and apply two coats of skim with proper trowelling stages. The result is a flat, polished surface that takes mist coat and emulsion cleanly.

