Flashing Against Existing Panel Siding

Measure over from the other panel to mark the top and bottom of the vertical cut and snap a line between the marks.

Flashing against existing panel siding.

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. It is always recommended to install step flashing behind stucco dryvit wood panel lap siding vinyl siding cedar shingle siding etc. 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. 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.

Again allow for a 1 4 inch gap. 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. But the j cap also creates a consistent line. 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.

Cut 1 4 inch above the flashing or window. However in most instances step flashing should be installed behind siding. A key part of my approach is using a special piece of flashing at this vulnerable intersection called kickout flashing or kickout diverter. In certain instances flashing may need to be installed on the exterior of siding.

If the shingle already has flashing on it the kickout flashing has to slip beneath it and you ll have to loosen or remove siding to do this. Hold a panel at the correct height and against a window or other obstruction to mark for the horizontal part s of a cutout. On a wall to be covered with wood cement board vinyl or metal.