Flashing Against Existing Panel Siding

Since newer installation guidelines do not recommend caulking this joint but instead recommend leaving a small gap and flashing behind the ends of the siding i think it is more prudent to add flashings when it is possible to do so.

Flashing against existing panel siding.

On a wall to be covered with wood cement board vinyl or metal. Install the kickout flashing underneath the first shingle photo 1. Measure over from the other panel to mark the top and bottom of the vertical cut and snap a line between the marks. In certain instances flashing may need to be installed on the exterior of siding.

Unless you re careful step flashing can allow water from the roof to slip behind the gutter and get behind the siding and even the housewrap. Flashing is a strip of metal usually aluminum about 8 inches long and bent at 90 degrees with each side at least 5 inches wide. Flush the end of the flashing length with the wall corner and secure the flashing to the framing with an 8d nail at each wall stud. But the j cap also creates a consistent line.

Hold a panel at the correct height and against a window or other obstruction to mark for the horizontal part s of a cutout. Begin at either end of the wall and set the level middle section of the z flashing onto the top edge of the siding panel with the wider flange upward and against the wall framing. However in most instances step flashing should be installed behind siding. Using a metal j flashing between these types of transitions provides a barrier between siding and transitions that protects against water intrusion.

Again allow for a 1 4 inch gap. A key part of my approach is using a special piece of flashing at this vulnerable intersection called kickout flashing or kickout diverter. Install the flashing before you finish the top of the brick wall as the flashing must go behind the siding as well as behind and under the top row of bricks that angle outward to cover the top.