What preparations should I make before installing exterior door flashing?

Before installing exterior door flashing when installing a new exterior door, you must perform a few other tasks. This involves preparing the new door opening. Begin by checking the wall for wiring, pipes, and cables. The next step is to cut the studs with a reciprocating saw, cutting through the sheathing and the siding as well, in order to form a rough opening that is just a few inches wider than the door. Then install a 2-by-4 on each side of the door opening. Trimmer studs and a double header made from 2-by-12s must then be installed. These steps must all be completed before beginning to install the door flashing.