2026-05-20
Skimming vs re-plastering: what do you actually need?
Skim coat or full re-plaster? Here's how to tell which one your walls need — and why it matters for the final finish.
A skim coat is a thin top layer (around 2–3mm) of finishing plaster applied over an existing sound surface. It's perfect for tired but solid walls that have hairline cracks, old filler patches, or just a tired finish you want freshened up.
A full re-plaster means hacking off the existing plaster back to the brick or block, and starting again with a backing coat (browning, bonding or hardwall) before the skim. It's a much bigger job — but it's the right call when the existing plaster is blown, damp-damaged, or hollow when you tap it.
How to tell which you need: tap around the wall with your knuckle. A solid, dull sound = the plaster's bonded. A hollow, drum-like sound = it's blown and likely needs taking off.
If in doubt, ask Darren to take a look. He'll give you a straight answer rather than upsell you to a bigger job than you need.