Installing Window and Door Trim
Install J-channel along the top and sides of door casings and
around windows.
NOTE:
When installing J-channel around replacement
windows that do not have nail flanges, add flashing for
greater protection against water infiltration. For an
example of completed flashing, see the previous page.
There are two methods of joining J-channels at corners. The
easiest method is to square cut the corners. For a more
finished appearance, you can miter the corners. To prevent
gaps, do not butt ends. Instead, lap them as shown.
To Square Cut Corners
Install J-channels at sides of windows. Notch as shown.
NOTE:
For best results, use aviation snips when cutting
J-channel.
Cut top and bottom J-channels so the ends extend beyond
the casing to the width of side J-channels.
Place top J-channel along the casing shoulder and nail it to
the wall.
Make two cuts in the bottom of the upper channel and bend it
down to overlap side J-channel. Repeat for the other side.
This forms a water drain and allows J-channel to receive
siding panel.
Nail the bottom J-channel in place. Cut the channel as
previously described. Fold rain tabs into receiving pockets for
a tighter miter joint.
To Miter Cut Corners
For best results, make sure you cut all J-channels to the
proper length, leaving the proper allowance for the width of
the face of the J-channel.
Square cut the bottom J-channel so that its ends extend
beyond the window casing to the width of the face of
the side J-channels. Notch the ends for clearance.
Position and nail the J-channel.
Measure side J-channels, adding the width of both the top
and bottom J-channels. Miter cut (45° angle) the lower ends of
both side J-channels. Notch the channel, position and nail.
Mark the top J-channel so its ends extend beyond the casing
to the width of the side J-channels. Miter cut (45° angle) the
ends. Cut and bend water tabs. Position and nail.
rain tab
3/4"
3/4"
3/4"
3/4"
(3/4" or
dimension of
J-channel
face)
3/4"
3/4"
37
Wolverine Fit and Finish Installation Guide
