What is it?
Fine cracks in the surface layer of plaster on walls or ceilings.
What does it look like?
[Insert Photos] Often “spider-web” or “map” patterns of very thin lines.
Common causes
1. Plaster drying too quickly (crazing)
2. Blown plaster (losing bond to the wall)
3. Vibrations (e.g., nearby traffic)
4. Seasonal temperature changes
How serious is it?
Rating: Low Concern. Almost always cosmetic. If the plaster sounds hollow when tapped, it has “blown” and may fall off.
How to tell which cause you have
Tap the wall. A hollow sound means blown plaster. If it’s solid, it’s just surface crazing.
What should you do next?
If solid, use a fine surface filler. If blown, the plaster needs to be hacked off and replaced.
Typical repair options
Skimming, patching, or using lining paper to hide fine lines.
Typical repair costs (UK)
£50 – £400 per wall.
Frequently Asked Questions
1. What is ‘crazing’? Fine surface cracks from fast drying.
2. Why does my plaster sound hollow? It has detached from the wall.
3. Can I paint over plaster cracks? Only after filling them.
4. Are plaster cracks normal in old houses? Yes, very common.
5. Does damp cause plaster cracks? Yes, it can weaken the bond.