Installation Instructions

CertainTeed Vinyl Siding Installation Guide

Using Lineals as Gable Trim

You can give gable end trim a more dramatic appearance by using

3-1/2" or 5" lineals instead of J-channel.

To install the lineals:

Make a pattern duplicating the gable slope. To create an angle

template, lock a piece of lineal into the previous course of siding or

other gable starter. Hold a second piece of lineal or starter against

the slope and transfer the angle with a pencil.

Transfer the angle of the template to the end of a length of lineal.

Cut away the lineal face and nail ﬂange.

Turn the pattern over and transfer the opposite angle to the

second lineal. Trim the nail ﬂange and receiving channel from the

opposite lineal to this line. Do not cut the lineal face.

Insert the full-faced lineal into the mitered lineal. If the nail ﬂange

or return lips butt and prevent a tight ﬁt, trim off additional material

from the second lineal.

Installing trim at roof line

To prevent water inﬁltration along the intersection of roof and wall,

install ﬂashing before installing J-channel. At points where vinyl

siding and accessories will meet at a roof line—such as areas

where a gable dormer or a second story side wall intersect with the

roof —it’s best to position the J-channel so it is a minimum of 1/2"

away from the roof line. Placing the J-channel directly on the roof

line will subject it to a build-up of heat, which could result

in excessive expansion.

NOTE: If you use more than one length of J-channel to span a

wall surface, be sure to overlap them 3/4".

90º

starter strip

1/2" (min.)