Plint beams are supporting beams for a building. The entire building is being hold by plinth beam. It is build between the foundation and wall.

If the building is constructed in a water loggled area, plinth beam is higly vulnerable for water to enter through the porus gaps of concrete. This can be enterd to the walls throuh plinth beam. Hence it is higly reccomended to waterproof the entire plinth beam area

Normally a bitumen coating or membrane is provided over the plinth beam to provide a barrier between plinth beam and wall. This will terminate the water flow from ground to wall.