Dampness in buildings can occur due to poor design, faulty construction, or use of low quality materials. It allows moisture to penetrate through the roof, walls, or floors. This can lead to mold growth and unpleasant smells, causing respiratory issues for occupants. It also causes structural defects like efflorescence, plaster crumbling, paint flaking, and timber rotting. Dampness prevention methods include proper ventilation, dehumidifiers, avoiding storing items on roofs, using waterproofing treatments on surfaces, special construction techniques like thick walls and damp-proof courses, and integral treatments for concrete or mortar.

1. “How we prevent our Home from Dampness”
Engr. Muhammad Ali
Jr. Lecturer, Engineering Technology

2. • Dampness:
• Penetration of moisture in the building through
• Roof
• Walls
• Floors
• Dampness in building may occur due to bad design, faulty construction and use
of poor quality of materials.

3. • Effects of Dampness on occupants:
• Dampness and humidity are always an irritation to home.
• They often lead to create mold, and smells in home leading to unpleasant
environment.
• Members of the house always feel damp and they don’t like to stay in home for
much time.
• These mold can lead to severe allergies and breathing problems to house
members.

4. • Defects of Dampness on Structure:
• Efflorescence
• Softening and crumbling of plaster
• Bleaching and flaking of paint
• Rotting of timber
• Corrosion of metals.
• Deterioration to electrical fittings
• Growth of termites

5. • Sources of Dampness:
There two ways of Dampness:
Either the moisture is entering into home
• Through the foundation
• Splashing rain water on walls
• Penetration of rain water through unprotected tops
• Defective roof covering in case of sloped roofs
• Inadequate roof slopes in case of flat roofs
• Climatic condition
 Moisture can not escape

6. Find the root cause of dampness:
• First study your house properly. Look at the sides and roof of your house.
• Sometimes the roof are not constructed properly or tilted to one side and they accumulate
water during rain.
• Then they are absorbed by the roofs and walls.
• Also some people put unused items or leftover construction material on roofs which also
causes soaking of roofs
• Another reason if the land is not good upon which construction is done then the water will
raise to the walls as capillary water is another reason of dampness especially in ground
floors.

7. • Moisture Entrapped During Construction:
• Walls while being constructed are in wet conditions.
• These may persist moisture for a long period after the construction is over due to the use of
salty or alkaline water, which causes dampness in the building.

8. • Defective Material:
• Dampness is also caused due to soakage of moisture by the defective materials
like porous bricks, soft stones, etc. especially when they are used in external
walls.

9. • Poor Workmanship:
• In case, there is any leakage in the sewers, down water pipes, kitchens,
bathrooms, etc., it will be causing dampness in the building.

10. Ways to get rid of dampness

11. Ventilate your home properly:
• It removes the bad air, decreases the humidity, moisture content.
• creates a flow of wind
• condensation due to not opening of windows.

12. Get a dehumidifier:
• Dehumidifier will absorb all the air and it will squeeze out all the water
• It will reduce the moisture level in the room

13. Avoid putting flower vessels on roof:
• It will ultimately worsen the roof & you may need to do again grading

14.  The following are the methods that can be adapted for the
prevention of dampness in the buildings
 By surface treatment
 By special constructional techniques
 Providing a damp proof course
 By integral treatment

15. • By Surface treatment:
• The surface treatment consists in filling or blinding the pores of the material
exposed to moisture by painting a water-repellent material over the surface.
• Some of the materials employed are: Sodium or potassium silicate, aluminum
or zinc sulphates.

16. • By Special construction techniques:
• By constructing the external walls of sufficient thickness. By using the bricks of
good quality for constructing the external walls. By building the walls in rich
cement mortar.

17. • By providing Damp proof course (DPC):
The continuous layer of an impervious material, which is provided in between
the source of dampness and part of the structure is called a Damp Proof Course.
DPC has two types:
• Horizontal DPC
• Vertical DPC

18.  Horizontal and Vertical DPC:
Rising damp is the effect of water rising from the ground into property.

19.  By integral treatment:
The integral treatment consists in adding certain components to the concrete
or mortar during the process of mixing, to make itself impermeable.
For example, compounds like chalk, talc, fuller’s earth etc.

20.  DPC in basement:
• As basements are built below ground level, these are most likely to be
attacked by dampness from the soil below as well as from outside the walls.
• Gravel is filed between the walls of the basement and adjacent soil.