There are one or more than one causes can be reason for dampness a few of them was listed below
1. Faulty design of the structure
2. Poor workmanship or faulty construction
3. Poor quality material used in construction

The given cause maybe give easy access to moisture to the your flat from different places Rising moisture from flooring, rain penetration through walls , roof, and floors etc . the moisture entering in your flat from flooring, wall, terrace and travels in different directions and spread further under the effects of capillary action.

  1. Source of moisture from the ground – Generally the foundation dampness is cause when the building structure is constructed below the road level and water logging area where the subsoil of clay is commonly found through which dampness is easily rise under capillary action unless it will be properly treated.
  1. Source of dampness from rain water – Generally found the data of the flats of the building structure is directly exposed to heavy showers of rains. and if the joints between walls and beam or columns is plaster with poor material or workmanship it may be give access to Excess rainwater to enter in the wall.
  1. Source of dampness from humidity – In technical this also called Codensation .
    This kind of dampness problem within a building are usually indicator of humidity and ventilation problems within a property. this kind of dampness is could not caused by faulty construction or poor workmanship this dampness is Cause when warm air with vapour comes into contact with cold surface and is possible in the most common form of dampness in flat as result of inadequate ventilation.