DPC (Damp Proof Course)
Below is a pictographic list of various damp proof course and tray flashings which are commonly used in cavity brick construction. On the left side are notes on the external or wet skin of bricks and on the right there are notes for the internal skin of bricks.
Problems occur when damp proof course or tray flashing are installed in an inappropriate manner or are poorly terminated.
The pictographic list is to illustrate the various methods of installing damp proof courses and tray flashings.
Tray Flashing - Roof Parapet
INTERNAL
Moisture can not migrate downwards
in the internal skin of bricks.
The brick bond will be sacrificed.
EXTERNAL
Moisture can and will migrate downwards orupwards in the external skin of bricks.
The brick bond will be maintained.
Tray Flashing - Window/Door Head
INTERNAL
Moisture can migrate downwards or
upwards in the internal skin of bricks.
The brick bond will be maintained.
EXTERNAL
Moisture can not migrate downwards or upwards in the external skin of bricks.
The brick bond may be effected by differential brick growth.
Cavity Flashing - Window/Door Sill
INTERNAL
No moisture evident in the internal
skin of bricks.
EXTERNAL
Moisture can and will migrate downwards or upwards in the external skin of bricks.
The brick bond will be maintained.
Cavity Flashing
INTERNAL
No moisture evident in the internal
skin of bricks.
The brick bond will be maintained.
Lintel Tray - Door Head
INTERNAL
No moisture evident in the internal
skin of bricks.
EXTERNAL
Moisture can not migrate downwards out of the external skin of bricks through the door
head.
The brick bond will be maintained.
Lintel Tray - Door Head
EXTERNAL
Stepped DPC
INTERNAL
Moisture can not migrate upwards in
the internal skin of bricks.
The brick bond will be sacrificed.
EXTERNAL
Moisture can and will migrate downwards or upwards in the external skin of bricks.
The brick bond will be maintained.
DPC
INTERNAL
Moisture can not migrate upwards in
the internal skin of bricks.
The brick bond will be sacrificed
cavity may become bridged with
mortar.
EXTERNAL
Moisture can not migrate upwards or downwards in the external skin of bricks.
The brick bond may be effected by differential brick growth.
Stepped DPC
INTERNAL
A bond breaker is provided
EXTERNAL
Moisture can and will migrate downwards or upwards in the external skin of bricks.
The brick bond will be maintained.
Bathroom DPC & Reglet Cavity Flashing
INTERNAL
Moisture can not migrate upwards in
the internal skin of bricks.
The brick bond will be sacrificed.
The internal brick skin of the wall below
is protected.
EXTERNAL
Moisture can and will migrate downwards or upwards in the external skin of bricks.
The brick bond will be maintained.
