In the simplest terms, rising damp is a condition where moisture from the ground travels up through the pores in the bricks and mortar of a building, much in the same way that oil travels up through the wick of an oil lamp. Once rising damp has become established, this moisture can cause problems such as damp patches on walls, peeling paint/wallpaper, and eventually, plaster falling away from the wall. In the longer term, it can potentially lead to structural damage to the building, if left unchecked.
The symptoms of rising damp can often be confused with the symptoms of other damp problems such as lateral damp and condensation. These types of dampness require different methods of treatment, so it is essential that an expert is consulted to diagnose the type of dampness to be treated.