#  Blog

 24/02/2026##  Rising damp: causes, identification and the right solution for your home

Rising damp is ground moisture that travels upward through walls by capillary action, recognizable by damp patches, salts and peeling finishes, and can only be permanently resolved with a professional wall injection.

Rising damp occurs when ground moisture moves upward through small pores in walls.
Brick, mortar and natural stone act like a sponge when the damp-proof course is missing, damaged or aged.
The moisture gradually rises and causes visible damage in the **lower 20 to 120 cm of the wall**, sometimes even higher.

 ## Are you unsure whether you are dealing with rising damp?

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## Typical signs

- Peeling paint at the bottom of walls
- White salt crystals (salts, often referred to as “saltpetre”)
- Damp or darkened wall bases
- Loose or crumbling plaster
- Musty smell or mould growth
- Damp that keeps returning despite painting or drying

This guide helps you correctly identify rising damp and understand which solution works permanently.

## What exactly is rising damp?

Rising damp is ground moisture that is drawn upward through walls by **capillary action**. This mainly occurs in:

- Older homes without a damp-proof course
- Homes where the damp-proof course is damaged or missing
- Renovations with raised garden levels, terraces or paving against the façade
- Walls that remain in prolonged contact with wet soil

![Protector blog rising damp detail](https://protector.be/images/nieuwsberichten/protector-blog-opstijgend-vocht-detail.jpg)

## How can you recognize rising damp?

**Visible damp patches at the bottom of the wall** Usually visible within the lower 20 to 120 cm, often more pronounced after rainfall.

**Salt efflorescence (white salts)** White crystalline deposits on the wall, a very typical sign of rising damp.

**Peeling paint or plaster**
When moisture evaporates, salts push off finishing layers.

**Mould on skirting boards or in corners**
Walls remain damp for extended periods.

**Crumbling skirting boards or damp floor areas**
In more advanced stages of moisture migration.

## Causes of rising damp

**Missing or damaged damp-proof course**
Very common in homes built before 1980.

**Porous materials at the base of the wall**
Bricks and mortar readily absorb ground moisture.

**Raised ground levels**
Raised garden, terrace or paving against the façade.

**Construction defects or settlement**
Cracks can interrupt the damp-proof course.

**Saturated soil**
Prolonged wet soil increases capillary action.

## Why rising damp does not disappear on its own

Rising damp will keep returning as long as:

- No damp-proof course is installed
- Walls remain saturated
- Salts continue to accumulate
- Ground moisture continues to be drawn upward

Surface solutions such as painting, plastering or using dehumidifiers **hide the problem**, but do not solve it.

## Professional solution: wall injection

The most commonly used and effective solution against rising damp is **professional wall injection**.

### Benefits

- Stops capillary moisture absorption
- Works deep within the masonry
- Can be carried out in occupied homes
- Prevents new damp patches and salt damage

### Method

- Drilling injection holes at the base of the wall
- Injecting a moisture-repellent product
- Sealing the holes
- Curing period
- Restoring skirting boards and finishes

## What can you check yourself?

- Does the damp return after painting?
- Do you see white salt crystals?
- Are mainly the lower parts of the walls affected?
- Do you notice a musty smell at the bottom of the walls?
- Do the patches worsen after wet periods?

If yes, rising damp is very likely.

## When should you call in an expert?

### A professional assessment is recommended when:

- Damp patches keep returning
- Walls remain dark and wet at the base
- Salts are visible
- Plaster is coming loose
- Wooden skirting boards are swelling

### Protector carries out

- Moisture measurements at the wall base
- Capillary investigation
- Salt analysis if required
- Clear advisory report with action plan

[Ask us a question](mailto:info@protector.be?subject=I%20would%20like%20to%20receive%20some%20more%20information%20about%20Protector)

[Get a free quote](https://protector.be/index.php?Itemid=801&lang=en)

[ Call us for free 0800 30 163 ](tel:080030163)

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