5 Signs Your Walls Need Replastering (Not Just Filler)

Filler and a quick sand will fix most hairline cracks. But sometimes the plaster itself has failed and no amount of decorating will hide it for long. Here are the five signs we look for.

1. Hollow sound when tapped. Knock the wall with your knuckles. A solid "thud" is fine. A drum-like hollow means the plaster has parted from the wall behind it.
2. Cracks wider than a £1 coin's edge, or cracks that keep reopening after filling.
3. Bulging or wavy surfaces, especially on chimney breasts and around old fireplaces.
4. Brown tide marks or salt crystals (efflorescence) — usually a damp issue that needs treating before replastering.
5. Soft, chalky patches you can scrape away with a fingernail. That plaster has perished and won't hold paint.

Skim or full replaster?

If the underlying plaster is sound, a 3mm skim coat smooths everything out in a day or two and is far cheaper. When the bond has gone, we hack off back to brick, apply a bonding/backing coat and then skim — a longer job but the only one that lasts.

Honest answer every time: if a skim will do, we'll quote a skim.