Rising damp is caused by groundwater rising through the wall masonry by capillary action and is most commonly caused by the absence or failure of original damp proof courses. However, rising damp is widely misdiagnosed in existing buildings, based on the incorrect interpretation of visual evidence and the readings of moisture meters.
Penetrating damp is caused when moisture enters a building due to a building defect or the use of inappropriate materials.
Condensation is not only associated with new buildings but also affects historic buildings also. This is caused when internal moisture cannot escape and therefore condenses on cold surfaces.