Dampness is a major problem of building. Here we explain what are the causes of dampness in building. Effect of dampness in a building. Which material used to prevent dampness in a building. we try to explain causes and effect of dampness in building very simple way, which is easy to understand.
What are the Causes of Dampness in building:
The main causes of dampness in house are given below.
- Moisture through the foundation.
- Dampness in building due to rain.
- Dampness enters in building from the top of the compound wall and parapet wall.
- Dampness due to condensation of air.
- Due to Flat roof of a building
1. Moisture through the foundation:
Moisture of the soil rise from foundation to wall due to capillarity action, which is cause dampness in building.
2. Due to rain:
Sprinkling rain water on the exterior walls of the house makes the walls wet and moisture enters the house. In the same way, moisture enters the building due to leakage of the roof.
3. Dampness enter in building from top of compound wall and parapet wall.
Damp proofing coarse or coping should be placed at the head of the parapet wall to prevent moisture entering in the building.
4. Condensation of air:
As the air cools, the moisture in the air, freezes on the walls, ceiling and floor. Due to that moisture enter in building.
5. Flat roof:
If there is insufficient slope on a roof, moisture enters the house due to a little water filling.
6. Moisture enters the building due to the defect of the roof covering in the sloping roof.
7. Moisture enters in the building due to defects in the connection of rain pipes, due to defective joints in the roof.
What are the effect of dampness in building:
The effects of dampness are as follows:
- Dampness creates a harmful environment for health in the building.
- Due to dampness, corrosion of metal used in construction.
- Stains appear on the walls and roof of the building.
- Wood used in doors, window, cupboards, furnaces, etc., decays due to dampness.
- Electrical fittings deteriorate.
- Quickly spreading of termite due to dampness in building.
- The plaster begins to loosen.
- Damage of mats etc. laid on the floor.
- The infestation of mosquitoes in the house increases.
Also read: 5 Method to repair brick wall defects.
What are the materials used for damp-proofing in building:
Different material used for damp proofing are given below.
- Hot bitumen
- Mastic Asphalt
- Bituminous felts
- Metal sheets
- Cement Concrete
1. Hot bitumen:
Asphalt is a flexible material. To prevent dampness in building by using bitumen, bitumen is laid on a concrete or masonry floor in a 3 mm thick layer. It is very common material which is commonly used in past.
2. Mastic Asphalt:
It is a semi rigid material. Mastic asphalt is also used as above process to prevent dampness in building. It comes out due to extreme pressure or heat.
3. Bituminous felts:
It is a flexible material. It is available in the form of sheets. Sheet wide similar to wall. The sheet is laid over a layer of brick or concrete. Then over it masonry work do.
4. Metal sheets:
Sheet of lead, copper, aluminium etc. can also be used as a damp proofing cover.
For damp proofing in building by using stone, two layers of good quality and high density stone like granite or slate are laid on the walls with cement mortar.
A waterproof layer can be made by laying a layer of bricks that absorb less than 5% water.
A layer of cement-sand mixture made in the ratio of 1: 3 is used on the wall to prevent dampness in building.
8. Cement Concrete:
10 to 15 cm thick layer of cement, sand, gravel is laid in the ratio of 1: 2: 4 on wall. Often rods are also arranged in this layer.