Damp Patch Through Plaster
A wet or discoloured area on plastered walls, often with a musty smell or salt crystals forming on the surface.
What Is Causing This?
- 1Penetrating damp from external wall defects
- 2Rising damp from a failed damp proof course
- 3Condensation on cold wall surfaces
How Urgent Is This?
This should be fixed in the coming weeks. Leaving it may allow the problem to worsen and cost more to repair.
What Needs to Be Done
The damp source must be resolved first. A plasterer will then hack off contaminated plaster, apply a salt-inhibiting render, and re-skim the wall.
How Much Will It Cost?
National average estimate
Labour: £188 – £513 | Materials: £53 – £185
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Prices are estimates based on typical UK rates. Actual costs depend on the specific issue, accessibility, and your location. All quotes from tradespeople on Tradesfolk are completely free.
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Ask a QuestionPlanning Permission Guidance
Some fixes for this problem may require planning permission or building regulations approval. Check if your project needs permission:
How to Prevent This
Investigate and fix the damp source before replastering. Use renovation plaster or tanking slurry on walls prone to damp. Ventilate rooms adequately.
Related Problems
A persistent discoloured patch on an interior wall, often yellowish or brownish, that may feel damp to the touch.
Damp and discolouration on ground floor walls, typically up to about one metre from the floor, with a tide mark.
Plaster that sounds hollow when tapped, feels soft, or bulges away from the wall beneath.
Other Plasterer Problems
Cracks running through the plaster on an interior wall, from fine hairline cracks to wider splits.
Plaster that sounds hollow when tapped, feels soft, or bulges away from the wall beneath.
Textured Artex coating on the ceiling that you want removed for a smooth, modern finish.
Plaster developing bubbles, blisters, or a bumpy texture on the surface, sometimes with paint lifting over the top.