How to Spot Rising Damp: The Key Warning Signs

Rising damp occurs when groundwater travels upward through a wall by capillary action. It typically affects the lower metre of a wall and leaves characteristic signs that, once you know what to look for, are hard to miss.

The key signs of rising damp:

1. Tide marks — A horizontal staining line on the lower part of the wall, usually below 1 metre, shows where the rising moisture evaporates.
2. Salt deposits (efflorescence) — White crystalline deposits on the wall surface are caused by salts carried up in the groundwater.
3. Plaster damage — Plaster on affected walls often blows, bubbles, or crumbles due to salt contamination.
4. Damp smell — A musty smell in ground-floor rooms, especially in older properties.
5. Peeling wallpaper or paint — Moisture pushing through the wall causes decorative finishes to fail.

What rising damp is NOT:

Many cases diagnosed as rising damp are actually condensation or penetrating damp. A professional damp survey is essential before any treatment begins. Treating the wrong type of damp is expensive and ineffective.

If you're seeing these signs in your South London or Surrey property, give Shadbolt Plastering a call for a professional damp survey.