The penetration or excess of moisture inside the building from its walls, floors, or roof is known as dampness in the buildings.
Sources of Dampness in the buildings
The following are the main sources due to which dampness occurs in the building.
- Moisture penetrating into the building through defective construction such as rainwater, pipes, leaking roofs, leaking or blocked gutters, etc.
- Damp rising from the soil either from bottom or from the ground surface, adjacent to the wall.
- Moisture penetrating the walls due to the rain beating on them during continued wet weather.
- Damp rising from the ground either because there is no damp proofing course or because the existing DPC has been bridged by the earth outside, being banked up to form a floor bed or another purpose.
Effects of Dampness in the building
The following are the main effects of dampness in the building.
- It causes rots to the timbers used in the building.
- It causes corrosion of the metals, used in the construction of the building.
- Electric installations get destroyed.
- It causes softening or crumbling of plaster.
- It damages the wall & paint.
- Damage the brickwork.
- The flooring of the building remains ugly since it cannot be cleaned well.
- Carpets used on the floor of the damped building get damaged.
- It reduces the life of the whole structure.
- It creates unhygienic conditions for the peoples in the building and affects their health.
- Breeding of mosquitoes and creates unhealthy conditions.
Causes of Dampness in the building
(a) Rain Penetration: Properly constructed walls offer considerable resistance to rain penetration but it may occur through the joints and porous bricks or stones. Rain penetration also occurs through the roof components, cracks, and joints between the walls and the roof.
(b) Level of the Site: Structures built on a higher ground level can be drained off easily so, they are less affected by dampness. But low lying areas cannot be easily drained off which causes dampness in the structure.
(d) Climatic Conditions: Dampness is also caused due to the consolidation of moisture present in the atmosphere under a very cold climate.
(e) Defective Orientation: The buildings having its walls subjected to direct showers of rain or getting less amount of sun rays, due to defective orientation is liable to dampness.
(f) Defective Construction: If there is any leakage in the sewers, down water pipes, kitchens, bathrooms, etc. It causes dampness in the building.
(g) Defective Materials: Dampness is also caused due to the soakage of moisture by the defective materials like porous bricks, soft stones, etc especially when they are used in external walls.
(h) Moisture Entrapped During Construction: During construction, walls are in wet condition. Due to that moisture causes dampness in the building.
Precautions from Dampness in the building
Use the following things as a precaution from the dampness in the building.
- The site is selected such that water is sunk in a pit at least 10 ft below the surface of the ground even in the wet season.
- Make the ground surface surrounding the building slope away from the house so that rainwater drains away before it has time to collect.
- If the building is on a hillside, make sure that the land above the house is adequately drained around the building and not through it.