THRESHOLD/JAMB UNIT No1
Threshold/Jamb areas are tricky to detail on site. The best solution is to use a preformed unit which allows for the continuity of the DPC through the door opening.
If there is a loss of continuity, it can lead to water tracking its way into the building, which in turn leads to staining/efflorescence of the plaster around the door. This finally leads to deterioration of the plaster and any wooden architecture of the doorway.