Today we will be showing you how to cut and install J Channel to trim out around a window in order to install vinyl siding. Starting with the bottom, cut a piece of J channel about 2 inches longer on each side of the window.
Mark the corners of the window.
Cut the J channel as shown, leaving the face on both sides:
After cutting a piece for the sides 4 inches longer in height than the side of the window, mark the window as shown:
Trim both sides using the marks.
Slide the sides of the J channel into the bottom. Nail the sides of the J channel to the high sides of the material on the wall.
Finish the corner by trimming the point on the corner.
The same procedure is used on the top of the window or a door. Mark the corners.
Trim the J channel leaving the face.
Mark the top piece on the sides.
Trim the J channel using the marks.
Slide the top J channel into the sides.
The window is ready for siding now.
Caulk the J channel to the window to finish the job.
Here is the J channel at the bottom of a door.