 In common with most other forms of dampness, rising damp is often misdiagnosed in buildings.Many misdiagnose a wall stain as rising damp instance due to misinterpreting the visual evidence of the wall and the readings of moisture meters.In simple terms rising damp occurs when ground water travels upwards through porous building materials such as brick, sandstone, or mortar, much in the same way that oil travels upwards through the wick of a lamp.