Housing
Dampness in Buildings
Dampness can be divided into 3 areas or causes, rising damp, penetrating damp or condensation. The first 2 of these are easy to summarise while the last, condensation, demands a detailed explanation.
Rising damp
This is water soaked up from the ground and is only a problem if the damp-proof course or damp-proof membrane is either damaged or bridged. A typical bridge would be the construction of a new drive or path at a higher level than the damp-proof course.
Penetrating damp
This is where water leaks into the building through a building defect. Sometimes a defect may be obvious. An example of this could be a missing roof tile which allows water to ingress. A less obvious example could be a leaking rainwater pipe that may not be apparent until the water soaks completely through the wall.
Penetrating dampness can be many different defects in the external fabric of the building. The effect is to allow water to get through the fabric of the building.
Condensation
This is moisture generated in the home. Household activities such as cooking, bathing, washing and drying of clothes, even breathing are major sources of moisture generation. Other causes of moisture can be from flueless paraffin or bottle gas heaters, and un-vented tumble dryers.
The temperature of the air in any given room will determine the amount of water vapour the air can hold. Moist air via air currents can permeate throughout the entire property from whatever source and consequently, when coming into contact with surfaces with a lower surface temperature, yield moisture in the form of condensation.
Keep doors closed, when these rooms are in use. This stops moisture reaching other rooms, especially bedrooms which are often colder.
How to inspect your home 
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