How to Install J-Channel Over Outside Basement Windows

Vinyl siding is attached around a window with a j-channel.

J-channel is used to secure vinyl or aluminum siding to the exterior wall of a home. When installing siding around a basement window, the j-channel is used to secure the siding around the window and to divert water. This is needed because there is no place to secure the siding close to the window. You can install j-channel over the outside of basement windows by first obtaining the siding you plan to install.

Things You'll Need

• Tape measure
• Paper and pencil
• J-channel
• Metal shears
• Hammer
• Nails

Instructions

1. Measure the width and height of the basement window with the tape measure. Add two inches to each measurement and make a note on a piece of paper.

2. Transfer the measurements in step 1 to strips of j-channel. Cut the j-channel to the required lengths with the metal shears.

3. Place one of the pieces of j-channel that was cut to the measurement for the height on one side of the basement window. Secure the j-channel to the window frame with the hammer and nails.

4. Place the other piece of j-channel, for the height, on the opposite side of the basement window. Secure it to the window frame with the hammer and nails.

5. Place the piece of j-channel that was cut to the measurements for the width on the top of the basement window. Secure the piece of j-channel to the exterior wall by nailing it to the window framing with the hammer.

6. Repeat this process to install the j-channel over the outside of another basement window.

Tips & Warnings

• Leave a small gap between the nail and the j-channel to allow for movement of the vinyl or aluminum siding.

• The tabs on the side of the j-channel should bend to overlap.

• If you drive the nail flush to the j-channel, the siding will not be able to expand and contact properly.

References

• The Family Handyman: How to Install Vinyl Siding