Wolverine Siding and Vinyl Carpentry Soffit and Decorative Trim - Manual (Page 109)

Trimming Curved Openings
Flexible J-channel simplifies installations around curved
objects such as half and full round windows. To install around
the top of an arched window, follow these simple steps:
Measure the circumference of the arch, then add 1-1/2" to
allow for overlap of the bottom J-channel.
Place the channel along one side of the window, leaving a 3/4"
section below the bottom edge of the window sill (shown).
Position the first nail at the base of the arch. Drive the nail
through the flange, tightly securing the flexible channel.
NOTE: This is an exception to the rule that says don’t
fasten vinyl tightly. When installed around curved objects,
flexible channel must be nailed tightly.
Place additional nails every 6" along the flange. Again, nail
tightly. Be sure the last nail is positioned at the base of the
opposite arch.
Using a utility knife, cut through the back of the channel, at the
point where it extends beyond the bottom edge of the window
sill. Make a second cut perpendicular to the first at the base of
the channel face. The length of the cut should equal the length
of the extension (shown).
Put a 90° bend in the channel, then nail the resulting tab under
the window (shown).
Repeat at opposite ends of arch.
To install the bottom J-channel, square cut the corners to
overlap the flexible J-channel. Use the same technique
described under “Installing window and door trim” (page 37).
Use pop-rivets to secure corners (shown). Use washers on the
inside of the rivets to prevent pull through.
NOTE: Remember to properly flash all windows.
108
SECTION 9 – Special Situations
Wolverine Fit and Finish Installation Guide
6"
3/4"
3/4"
90°
window
bottom
pop
rivet