What cause Dampness in a building? and what are the materials can be used to prevent dampness?

Structural dampness is the presence of unwanted moisture in the structure of a building, either the result of intrusion from outside or condensation from within the structure.

A high proportion of damp problems in buildings are caused by condensation, rain penetration or rising damp

Dampness tends to cause secondary damage to a building. The unwanted moisture enables the growth of various fungi in wood, causing rot or mold health issues and may eventually lead to sick building syndrome. Plaster and paint deteriorate and wallpaper loosens. Stains, from the water, salts and from mold, mar surfaces. The highest airborne mold concentrations are found in buildings where significant mold infestation has occurred, usually as a result of severe water intrusion or flood damage. Molds can grow on almost any surface and occurs where there is a lot of moisture from structural problems such as leaky roofs or high humidity levels. Airborne mold concentrations have the potential to be inhaled and cause serious health effects in humans.

Externally, mortar may crumble and salt stains may appear on the walls. Steel and iron fasteners rust. It may also cause a poor indoor air quality and respiratory illness in occupants. In extreme cases, mortar or plaster may fall away from the affected wall

i agree with Mr osama in ans .

THERE ARE MANY REASONS BEHIND THAT SUCH AS

- HIGH WATER LEVEL WHICH CAUSE DAMPNESS IN BASEMENT AND GROUND FLOOR LEVELS

- OR MECHANICAL

-

POOR VENTILATION NATURAL

- USING INSULATION-WATER-IN A GOOD WAY PROTECT THE BUILDING

I agree with the answers of Mr. Osama and Mr. Yasser.

CAUSES:

1. Loose or No Damp Proof Course.

2. High water Table.

3. unsatisfactory Drainage of surface water.

MATERIALS:

1. Strong DPC (Bitumen)

2. Good leveling for Surface Water Drain.

3. Insulation(Thermopore/Foam) / cavity Walls.

4. Natural cross Ventilation.

dampness in a building is because of faulty design. When the moisture in a cool building is high due to high outside temperatures. The moistures can come trough faulty design if there isn't a moisture boundary (foil ie.) But put the moisture boundary on the good side of the structure otherwise moist will built up in the structure.

It prevents the loss of water from cement paste which affects the strength of concrete slab and it also enhances the movement of concrete slab relative to sub-base layer and reduces the frictional forces developed at their interface.

Hi, 

Dampness happen with trapped or rising water due to faulty design, to remove or eliminate use chemical injection to create a barrier or can do surface treatment by using capillary water proofing which will react with moisture and will penetrate into concrete

I think the dampness of the house is dangerous because it can cause the appearance and spread of mold, which is especially dangerous for human health. I noticed that due to the high humidity and heat in the bathroom, traces of mold appeared, so I immediately began to look for a company providing mold remediation services. I'm worried about it, so I want to get rid of the mold as soon as possible.