Dampnessin walls: causes, prevention and remedy.

DAMPNESS IN WALLS: CAUSES, PREVENTION AND REMEDY

Ever entered a room and wondered why the paint is bubbling or powdery? Well, these are indications of dampness in walls, caused by presence of excess moisture.  This is harmful to both the structure and the occupants, as it causes leakages, paint peels and cracks and the molds can negatively impact on health. This article will help you to understand the cause, prevention and remedy to dampness in walls.

Figure 1: Dampness originating from water penetrating from a flower garden.

Possible causes of dampness in walls

Dampness in walls can occur as a result of either of the following causes:

1. Water penetrating through the walls from leaking roof gutters, missing roof tiles, dripping pipes, external wall cracks or porous bricks
2. Water being absorbed from the ground
3. Condensation of water on walls or a combination of more than one factor.

The first step to successfully address the problem of dampness in walls is to correctly identify the cause of the dampness, to avoid using the wrong remedy which ends up being costly and ineffective.

Types of dampness and proposed remedies

1. Dampness from penetrating water

Look out for signs such as discoloration of the ceiling on areas near the damp section of the wall, possible water entry points such as damaged or missing roof tiles, faulty gutters, condensation of moist air, leaks around windows, doors or roof intersections. Investigate if there are seasonal patterns such as dampness increasing during rainy season, and water flowing down the walls.

Figure 2: A little plant growing on the wall causes cracking, leading to water leakage and dampness

To cure dampness originating from  water  penetrating through the wall, consider either or a combination of the following:

• If the damp patches are around windows or doors, its possible that water is getting in through gaps around the frames, hence this should be sealed.
• If caused by leaking roof or pipes, repair the faults or fix the leaking pipes
• Dampness as a result of condensation of water around the walls, install moisture extractor fans or vents in places such as the kitchen where moist air is produced
• Ensure drainage systems such as gutters are cleared before onset of the rain season to prevent water from collecting
• Use gutinizing technique which involves coating pipes and walls with a thin layer of concrete to make them waterproof by preventing porosity.
• Ensure areas that are likely to be affected by water seepage or leakage are properly water-proofed
• Apply pressure grouting, which involves filling crack and crevices with cement mix to prevent water seepage.

2. Dampness from rising water

This type of dampness is caused by ground water rising through the walls as a result of capillary action. It is important to note that while this is a natural process, not all walls experience this.

Its usually caused by high moisture content of the ground and lack of regular damp proofing during construction. To prevent this kind of dampness, the following should be done:

Figure 3: Dampness originating from the foundation

• Damp-proof structures at construction stage by using materials such as bitumen, mastic asphalt, slate, plastic sheets, cement concrete