Installation Instructions

CertainTeed Vinyl Siding Installation Guide
113
Half-Round Shingles in Gable Ends
NOTE: The following instructions focus on a gable installation.
They also are geared towards an enclosed gable, started with
a J-channel. The Half-Round can also be started with starter
strip. This is an example only!
Installing receiving channels
Frame the border area with 3/4" J-channel. Nail in place loosely.
Miter joints accordingly.
NOTE: You also can use 3-1/2" or 5" lineals to frame gable
ends and gable base. For instructions on cutting lineals for
peaks, see “Gable Trim” on page 67.
Cut enough J-channel to span the base of the gable; then secure
it in place.
NOTE: The instructions below show how to create a gable
installation with a complete, centered Half-Round at the peak.
Making the starter course
Gable installations properly terminate with a single round at the
peak. To create this effect, you usually have to adjust the height
of the starter course.
To determine the height of the starter course, calculate the number
of rows required to complete the gable.
Use the following formula:
Gable height (inches) ÷ 12.5 (face exposure) = courses required
NOTE: Gable height is measured from inside the horizontal
receiving channel to the peak (allowing 1/4" at top and
bottom for expansion).
For example, with a 68" gable height, the calculations would be
68 ÷ 12.5" = 5 with a remainder of 0.44. This means you would
need 5 full courses plus 0.44 x 12.5" (face exposure of panel) =
5.5" measured from the top edge of the gap on the upper course
(illustrated). This is the visible height for your starter course.
The visible height is the vertical dimension of the panel you’ll
see below the first full row of rounds.
Once you’ve determined the visible height of the starter course,
mark this dimension on a Half-Round Shingle panel. Measure from
the top of the gap on the upper course (illustrated). Draw a cutting
line the entire length of panel.
Cut and use the top section, which contains the locks, as your
starter course. Cut enough panels to span the base of the gable.
gable
height
5-1/2"
5-1/2"
top of gap
remove
cut