Preparation for Horizontal Siding

Preparing Wall Surfaces
Sheathings
In new construction, apply sheathing first, then nail
accessories over it.
The application method you choose determines the width of
the recess opening required. For example, use:
• 1/2" opening when applying accessories over sheathing
and installing siding with a panel projection of 1/2" or less.
• 3/4" opening when applying accessories over sheathing
and installing siding with a panel projection of 3/4" or less.
• 1-1/4" opening when applying accessories first and using
sheathing that’s less than 3/4" thick for sidings with a
panel projection of 1/2" or less. For sidings with a panel
projection of 5/8" or 3/4", use a sheathing that is 1/2"
thick or less.
New Construction
Make sure all studs are straight and true. Correct any bowed
studs.
NOTE: Vinyl siding must be applied over a rigid sheathing
that provides a smooth, flat surface or an underlayment
(such as wood, wood composition, rigid foam or fiber
sheathing) that is no more than 1" thick. Vinyl siding
cannot be applied directly to studs.
If you’re planning to use a conventional house wrap or building
felt, apply according to the manufacturer’s recommendations.
In all cases, however, install the products so they are secured
firmly to the substrate so that they provide a smooth, even
surface for the final siding installation. Make sure sheathing is
fastened securely to studs.
Vinyl siding is an exterior cladding; it is not a complete
weather resistant barrier. Before applying siding, make
certain the substrate is watertight. In order to be protected
from precipitation, the substrate may need to be properly
flashed around areas such as windows, doors, other openings
and corners so as to shed water to the exterior. The siding
alone is not meant to be a watertight barrier.
Drop-In Foam Backer Boards
Some drop-in foam backers can restrict the movement of vinyl
siding. Therefore, CertainTeed vinyl siding may not be applied
over any drop-in foam backer other than a contoured drop-in
foam backer designed specifically for each profile.
IMPORTANT: CertainTeed will not accept any responsibility or
liability in the event the drop-in foam backer restricts the
movement of the vinyl. The use, fit, and performance of the
siding backer board is the responsibility of the installer and the
backer board manufacturer.
NOTE: Contoured drop-in foam backer boards are not a
substitute for rigid foam sheathing.
Home Improvement Projects
You can prepare your current siding surface to receive vinyl
siding in one of three ways:
Strip off old siding and level the wall. If felt paper covers the
wall, you have two alternatives: either strip it off completely or
staple or nail it to create a smooth surface. If there is no solid
sheathing under the old siding, you must apply it as described
in the instructions for New Construction.
Apply rigid sheathing to existing siding to provide a
smooth surface. Nail securely to old siding. Nail evenly
to bridge low spots.
NOTE: Failure to establish a smooth, solid surface
constitutes misapplication under the terms of the
warranty.
Apply vertical furring to old siding to straighten noticeable
surface unevenness. (See “Tips for applying wood furring.”)
Then apply rigid sheathing, following the instructions
presented under New Construction.
NOTE: For information on installing siding over asbestos
and for historic applications, see page 136.
Tips for applying wood furring
If you are working on an older home with noticeably uneven
walls, you must correct this condition before proceeding. If not
corrected during preparation, this uneven surface will produce
a wavy appearance in siding applied over it.
For best results, space horizontal furring strips 12" on center.
Do not exceed 16". To correct an uneven wall, use furring
strips (and wood shims if necessary) to eliminate low spots.
NOTE: You must apply rigid sheathing over furring.
CertainTeed Vinyl Siding Installation Guide
21
stucco
1 x 3 furring
ring-shanked
nails for
attaching furring
foam sheathing
16"
sill
undersill trim
J-channel
siding
siding
undersill trim
J-channel
sill
furring strip/foam shim
furring strip/foam shim
CertainTeed Vinyl Siding Installation Guide
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When covering over masonry or bricks, it’s better to use
1"x 3" furring. For best thermal performance, install a
minimum of 1/4" foam over furring strips.
Furring and/or foam is also used below eaves and windowsills
to maintain correct slope angles when siding panels must be
cut to a narrower dimension to fit.
Similarly, when panels are cut to fit over doors or
windows, furring and/or foam is used to establish the
correct slope angle.
Applying over stucco or masonry
When applying vinyl siding over stucco or masonry, you first
have to be sure you’re working on an even surface. To create
that surface, you may have to knock down high spots where
furring strips will be applied. Use caution when chipping off
these spots – you don’t want to crack or damage the
remaining stucco or masonry.
Apply 1" x 3" furring over the stucco or masonry using ringshanked
nails or screws. Stucco will not hold fasteners tightly,
so be sure nails or screws are anchored securely to studs.
Furring strips should be spaced 16" on center.
Applying rigid foam sheathing to furring
Install sheathing according to manufacturer’s instructions.
Do not apply siding directly to furring strips. For best thermal
performance, install a minimum of 1/4" foam over furring strips.
Applying over steel studs
Pre-planning is the key when installing vinyl siding and
accessories over steel studs. Pre-planning includes the
selection of siding style and the types of accessories. Preplanning
proper stud placement will eliminate many of the
problems that could surface once the job has been started,
such as at corners, windows, and transitional areas.
Follow the same guidelines as in a wood surface – except for
the type of fasteners used. Wall sheathing must be installed
over the studs. This will provide a straighter, smoother and
more rigid wall surface and help prevent studs from twisting.
Siding must be secured into metal studs if the substrate is not
a nailable surface such as exterior dry wall, gypsum board, etc.
The application of vinyl siding, soffits and accessories over
steel stud framing rather than typical wood framing is straightforward.
The main difference is the use of screws to hang
components that make up a completed siding job.
Use noncorrosive, self-tapping screws with at least 5/16"
(9.5 mm) diameter head, 1/8" (3 mm) diameter shaft, and at
least 1-1/8" (29 mm) long.
Although the fastening method for steel studs differs from
wood construction, all other procedures still apply, including
fastening in the center of the nail slot and not overtightening
the fasteners.
Nailing, Stapling and
Other Fastening Methods
If you want to ensure a quality vinyl siding installation, focus your
attention on nailing techniques. Unfortunately, a lot of installers
don’t. They feel nailing is a routine task, something everyone
knows how to do. But that’s not the case. At CertainTeed, we
analyzed reported installation problems, and we found that
more than half of them can be traced back to improper
nailing. So if you want to save yourself lost time and frustration,
carefully observe the following guidelines when installing
accessories, siding panels, soffit, or porch ceilings.
Lock the panel and begin nailing at the center of the panel,
working toward the ends. This helps maintain a level line.
With horizontal accessories and panels, position the nails in
the center of the elongated nailing slots to allow for expansion
and contraction. Never nail through the panel surface.
With vertical accessories and panels, position the first nail at
the upper edge of the topmost nailing slot. This allows a
panel to hang from the nail. Position the remaining nails in
the center of the nailing slots. Allow for 1/3 of the total
expansion at the top and 2/3 of the total expansion at the
bottom.
CertainTeed Vinyl Siding Installation Guide
23
typical of a pan head,
“wafer,” “s” truss head
or washer head screw
sheathing or
substrate
center nail in slots
center of all slots
upper edge of
topmost
nailing slot
center staples in slots
up to 1/16"
too tight too loose correct
CertainTeed Vinyl Siding Installation Guide
24
NOTE: Do not nail too tightly. To permit expansion and
contraction, panels should hang freely from nails. This
allows the panels to move as the temperature changes.
Drive the nails until there is between 1/8" to 1/16" of
space between the nail head and the nailing flange.
Drive the nails straight in. Do not angle nails.
Per the ASTM specification for vinyl siding installation (D4756),
proper nail penetration is at least 3/4". In most cases, that
requires anchoring to studs.
Fastener Spacing
Fasteners are typically spaced a maximum of 16" apart. In
new construction, fasten to studs on 16" centers. Do not skip
studs. Some vinyl siding may be used in 24" on center
construction in areas without special wind-load requirements
(fasteners spaced a maximum of 24" apart). Check with your
local building code official for special requirements and
ICC-ES Evaluation Report ESR-1066 for specific wind-load
requirements.
Other fastening techniques:
Manual nailing is the most common way of fastening vinyl
siding to a wall. That’s because it offers greater control,
making it easier to learn how to fasten panels securely, but
not tightly. You also can use power screwdrivers or pneumatic
staplers/nailers to attach vinyl siding to a wall, but you must
take the time to develop the proper skills. If you choose to
use one of these alternate techniques, follow all the recommendations
above for nail positioning and spacing and the
recommendations for substrate preparation on pages 20-23 for
horizontal applications and page 69 for vertical, including Board
& Batten. In addition, be sure to observe the following guidelines:
Power screwdrivers
Use noncorrosive, self-tapping truss head screws. Screws
must have at least 5/16" diameter head and 1/8" diameter
shaft. Screws must be at least 1-1/8" long. If underlayment is
less than 3/4" thick and is not considered a nailable surface
(for example, foam or exterior grade gypsum), be sure screws
are long enough to penetrate at least 3/4" into wood studs
or substrate, 1/8" through a steel stud. Be sure screws are
centered in the nail slot. Leave 1/16"-1/8" space between the
screw head and the panel nailing flange.
Pneumatic staplers/nailers
Use corrosion-resistant fasteners only. Fasteners must be
centered in the nail slot, no more than 16" on center.
NOTE: Some power staplers/nailers use an attachment
that helps position the fastener in the nail slot. If your unit
does not have that feature, you must carefully position the
fastener by sight.
Fasteners must penetrate a nailable surface at least 3/4". Be
sure to leave up to 1/16" between the fastener and the panel
nailing flange. If you’re using a power stapler, drive the staple
perpendicular to the nailing slot with one leg of the staple
centered in the slot and the other leg above the panel.
NOTE: Check with local building codes to verify fastener
requirements for your area.
Expansion and Contraction
It’s normal for vinyl building products to expand and contract
with temperature changes. To ensure a successful siding
installation, you must allow for this movement during
application.
Use the following guidelines to determine the space required
for expansion and contraction between siding and trim:
1/4" at both ends of the panel when the ambient temperature
is above 40° F at the time of application.
3/8" at both ends of the panel when the ambient temperature
is 40° F or below at the time of application.
In a horizontal siding installation, a vinyl panel tends to expand
equally in both directions.
In a vertical siding installation, on the other hand, most of the
expansion is downward. So instead of allowing equal space
for expansion at both ends of a vertical panel, leave more
space at the lower end: 1/3 of the total expansion will occur at
the top of a panel, and 2/3 of the total expansion will occur at
the bottom.
3/16" at the top and 3/8" at the bottom when the ambient
temperature is above 40°F for up to 12' lengths.
1/4" at the top and 1/2" at the bottom when the ambient
temperature is 40° or below for up to 12' lengths.
Periodically check the panels to ensure that they can move
side-to-side. When installing siding or accessories vertically,
make sure the bottom of the panel or accessory can expand
downward without interference.
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1/4" to 3/8"
1/4" to 3/16"
3/8" to 1/2"
top most
nail at the
top of the
top most
full nail slot
center
remaining
nails in
the slot
starter strip
metal flashing
foundation
6-1/2"
for wide
corners
& lineals
4" for
standard
corners
chalk
line
8"-10"
CertainTeed Vinyl Siding Installation Guide
26
Installing Accessories
Snapping a chalk line
To ensure proper installation, you must establish a straight
reference line to guide the positioning of the starter strip and
the first course of siding.
If the house is reasonably level, find the lowest point of the old
siding (or sheathing if working on new construction). Partially
drive a nail at one corner, starter height minus 1/4" above the
lowest corner. Attach chalk line. Go to other corner and pull
the chalk line taut. Stretch the chalk line from this nail to the
opposite corner of the house. Make sure the line is level, using
a line level or 4' (minimum) level. Snap chalk line and repeat
the procedure around the entire house.
A water level, a long clear plastic tube 90% filled with water, is
useful in marking level points around the house and on
opposite sides of openings such as doors. Water will always
seek a level state, ensuring the markings will always be at the
same level.
NOTE: If after establishing a chalk line you find that your
starter strip will be positioned below an easily nailed
surface, you may have to apply a nailable base.
If you have added sheathing, you may want to bend trim coil
to act as flashing and help prevent entry of insects. Bend the
coil in a “Z” shape so the top edge of the coil is on the chalk
line and the bottom edge extends down over the foundation.
(See illustration.)
NOTE: The general guidelines for cutting and nailing vinyl
panels and for allowing for expansion and contraction also
apply to vinyl accessory items.
Installing the starter strip
Position the starter strip with the top edge on the chalk line
and the ends 6-1/2" away from the outside and inside corners
(when using lineal systems or wide corners), 4" if using
standard one-piece corners. Nail to wall following previously
mentioned nailing instructions. When hollows occur in the wall
surface, shim out the starter strip to avoid a wavy appearance
in the finished siding job. Nail every 8" to 10".
As you add starter strip sections, be sure to leave 1/4" space
between them for expansion.
Sometimes – especially at sills above garage doors, porches
or brick surfaces where the siding has been cut lengthwise–
you may find it easier to use a combination of utility trim and
J-channel as a starter strip to secure a panel (see illustration
on page 22).
housewrap
sheathing
Installing Outside Cornerposts
Flash the corners of the home by bending a 20" wide piece of
aluminum trim coil 90° so you have two 10" legs. Cover the
entire length of the corner, lapping the upper pieces over the
lower pieces. (Self-adhering flashing may be substituted for
trim coil. Follow manufacturer’s installation instructions and
observe local building code requirements.)
Position outside cornerpost with the top of the post 1/4" from
the underside of the eave and the bottom of the cornerpost
3/4" below the starter strip. Remove the bottom 3/4" of the
nailing flange so it will not show below the siding when
installed.
Make sure posts are straight and true before nailing.
Hang cornerposts by first positioning a nail at the top of
the topmost nail slot. Position all remaining nails in the center
of nail slots a maximum of every 8" to 10". Leave 1/8" to 1/16"
between the nail head and the cornerpost to allow the
cornerpost to move during normal expansion and contraction.
(DO NOT NAIL TIGHT.) This nailing pattern is to be followed
on both nail flanges of each post.
NOTE: CedarBoards corners install similar to standard
outside cornerposts.
NOTE: When installing Traditional, Beaded, and
SuperCorners™ or any hanging cornerpost longer than
12', position fasteners at the top two nail slots on each
side of the corner.
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1/4" to 3/8"
hang from top nail,
center remaining
nails
flashing
nail every 8" to 10"
3/4"
1/4" to 3/8"
hang from two
nails, center
remaining nails
flashing
3/4"
If posts must be spliced for high walls, you have two options:
Option 1: Cut 1" off the nailing flanges and back so just the
face of the outside cornerpost remains. Then lap 3/4" of the
upper post over the lower post, allowing 1/4" gap for
expansion. This method will provide an obvious joint between
the two posts, but will allow water to flow over the joint,
reducing the chance of water infiltration.
When the bottom edge of a cornerpost terminates into a
porch, deck, brick, stone ledge, or roof line, etc., allow 3/8" for
every 10' of corner when the ambient temperature is above
40°F; 1/2" for every 10' of corner when the ambient
temperature is 40°F or below.
Option 2: Cut a 6" length of cornerpost and trim the nail
flange, receiving channel, and sides until you have just a 90°
bend of vinyl. Using PVC primer and PVC cement, glue the
bent piece to the inside of the upper post and lower post. Butt
the two posts together. Nail the entire assembly as one post
with all nails in the lower post centered in the nail slots.
Also see additional instructions covering installation of
four-piece cornerposts (page 29).
1 pc. outside
corner piece
flashing behind finished
corner assembly
butted splice joint
splice backer (hidden)
PVC adhesive
on backside of
cornerposts
PVC primer and
PVC cement
must be used
cornerpost
splice
backer
CertainTeed Vinyl Siding Installation Guide
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1/4"
1"
Capping an outside cornerpost
One method of capping an outside cornerpost is to cut a
piece of J-channel twice as long as the width of the
cornerpost face. Mark a 90° angle from the center and cut
out this area. Then cut 7/8" away from each end, except for
the nailing flange. Bend the J-channel in the center and nail it
to the outside of the corner of the house. Then insert the
cornerpost into the J-channel.
Another alternative is to trim the nail flange, receiving channel,
and sides from the bottom 1" of the cornerpost. Notch 1" at
the 90° bend, fold the bottom 1" of the cornerpost face, and
fasten these “flaps” with a pop rivet.
Extra Wide Corner Posts
(Four-Piece Corner System)
Extra-wide cornerposts give you a distinctive, easy-to-install
method of finishing outside corners. Each cornerpost consists
of four parts: corner starter, two lineals, and a quarter-round
snap-in insert.
Lineals are available in two board styles: 5" smooth and
3-1/2" smooth.
The installation procedure is identical for all lineals and inserts.
To install this four-part accessory, follow these steps:
Before you begin, make sure the corners are flashed properly.
Cut cornerpost pieces. Measure the vertical span, and allow
1/4" clearance from the underside of the eave and 3/4" below
the starter strip. Cut all four pieces using a power circular saw.
CertainTeed Vinyl Siding Installation Guide
29
7/8"
long leg
of insert
1/4" to 3/8"
flashing
8" to 10"
3/4"
hang from
top nail, center
remaining nails
CertainTeed Vinyl Siding Installation Guide
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Hang a starter strip. Position the starter strip, leaving 1/4"
allowance for expansion at the top and 3/8" at the bottom.
Position the first nail at the uppermost edge of top nail slot
(shown). Nail loosely. Working from the top down, position
the remaining nails every 8"-10", with the nails centered in
the slots.
Attach the side lineals. Lock the first lineal into the starter strip.
Nail it to the sheathing, following the procedure described
above. Repeat the process for the other lineal.
Snap in the quarter-round corner insert. Working from the
bottom up, begin by inserting the longer leg of the insert into
the nail flange side of the starter strip first; then snap in the
shorter leg. Lightly press along the length of the insert as you
snap it into place.
NOTE: For a more secure installation, use a pop rivet to
attach the molding insert to a side lineal. The rivet should
be positioned at the top of the cornerpost.
Inside Cornerposts
There are three options for trimming inside corners: Standard
3/4" inside cornerpost, single J-channel, and two J-channels.
To flash the inside corner, bend a 20"-wide piece of aluminum
coil stock 90° so you have two 10" legs. Insert the flashing
into the corner. If you use more than one piece of flashing,
overlap the upper pieces of the flashing over the lower pieces.
To install inside cornerpost, hang the post from the top of the
eave. The bottom should extend 3/4" below the starter strip.
Remove the bottom 3/4" of the nailing flange so it does not
show below the siding. Set the post straight and true. Position
the top nail in the top of the nailing slot. All other nails should
be in the center of the nail slots.
solid nailable
substrate
corner flashing
(scrap aluminum
coil, for example)
standard 3/4"
inside corner post
single J-channel two J-channels
If you have to splice the inside cornerpost, cut 1" off all but
the outer face of the lower post. Lap 3/4" of the upper post
over the lower post, leaving 1/4" for expansion.
If you are using two pieces of J-channel instead of inside
cornerpost, flash the corner with a 10" x 10" “L” corner
fabricated from aluminum coil stock or any weather-resistant
barrier. Hang the J-channel from the top of the eave. The
bottom should extend 3/4" below the starter strip. Remove the
bottom 3/4" of the nailing flange so that it will not show below
the siding. Use the same positioning and nailing guidelines as
inside cornerpost.
To create a narrower corner, you can also use a single length
of J-channel and flashing. First, install the siding on one wall.
Then place the J-channel lightly against the siding and nail it
to the substrate on the adjacent wall. Follow the same
positioning and nailing guidelines as inside cornerposts.
Federal Corners
To create a federal-style corner, flash the corner with
aluminum trim coil or other flashing materials. Hang a new
construction starter strip. Position the top nail in the top of the
nailing slot. All other nails should be centered in the slots
spaced 8" to 10" apart.
Position and secure the 3-1/2" lineal.
Position and secure an aluminum starter strip.
Position and secure the 5" lineal.
NOTE: Aluminum starter can be used for both lineals. If
the aluminum starter used for the 5" lineal is not long
enough, fashion a starter using a metal brake and coil
stock to a length that allows for proper nailing into the
substrate.
CertainTeed Vinyl Siding Installation Guide
31
“L” shaped
flashing
inside
cornerpost
splice
“L” shaped
flashing
CertainTeed Vinyl Siding Installation Guide
32
Inside Federal Corners
Flash the corner with aluminum trim coil or other flashing
materials.
Position and secure the 5" lineals (or a 3-1/2" lineal) by butting
the lineal up to the inside corner. Using a 5" lineal will create a
symmetric 3-1/2" exposure in the corner. If two 3-1/2" lineals
are used, one exposure will be approximately 2-1/4" and one
will be 3-1/2".
NOTE: Attaching the second lineal will keep the first lineal
in place. You will not need a starter strip. Always position
the top nail in the top of the nailing slot. All other nails
should be centered in the slots spaced 8" to 10" apart.
Position and secure the starter strip.
Position and secure the remaining lineal.
Trimming Bay Window Corners
There are several ways to trim the odd angles of bay windows.
Here are two of them:
1. Install bay window cornerpost.
2. Install J-channel with a quarter-round insert.
Before you begin, make sure the corner is properly flashed.
Install Bay Window Cornerpost
• Cut bay window cornerpost to the proper length.
• For angles less than 45°, push down on the face of the
corner until the nail flanges seat flat against the wall
surfaces.
• Hang the cornerpost by nailing loosely into the topmost
nail slot.
• Make sure the cornerpost is straight and true.
• Position all remaining nails in the center of nail slots a
maximum of every 8" to 10". Leave 1/8" to 1/16"
between the nail head and the cornerpost to allow the
cornerpost to move during normal expansion and
contraction.
• Fit the siding into the cornerpost.
Install J-Channel with Quarter-Round Insert
• Cut two pieces of J-channel and one piece of
quarter-round insert to length.
• Pop rivet the J-channels to each side of the
quarter-round insert in at least three places.
• Nail the assembly to the corner, remembering to
hang the assembly from the topmost full nail slot.
• Position all remaining nails in the center of nail slots a
maximum of every 8" to 10". Leave 1/8" to 1/16"
between the nail head and the J-channel for normal
expansion and contraction.
• Fit the siding into the J-channels.
CertainTeed Vinyl Siding Installation Guide
33
for angles
less than 45°
pop rivets
remove
half of the
longer leg
nail loosely
every 8"-10"
push down until nail
flanges seat flat
for angles
45° and
larger
CertainTeed Vinyl Siding Installation Guide
34
Decorative Trim Options
around Windows and Doors
2-1/2" Window and Door Casing
System requires 2-1/2" window and door casing.
3-1/2" Snap-On Lineal
System requires 1" face J-channel.
3-1/2" Lineal System
System requires 3-1/2" lineals and starter strips.
5" x 3-1/2" Lineal System
System requires 5" lineals, 3-1/2" lineals, and starter strips.
3-1/2" Lineal System with Corner Block
System requires 3-1/2" lineals, starter strips, and lineal
corner block.
3-1/2" Lineal System with Corner Block
and Rosette
System requires 3-1/2" lineals, starter strips, lineal corner
block, and rosette.
35
CertainTeed Vinyl Siding Installation Guide
Window Flashing
If installing a new window and flashing, refer to the window
manufacturer’s instructions and ASTM E2112, Standard
Practice for Installation of Exterior Walls, Doors, and Skylights
for the proper flashing installation method for the window type
and wall configuration of the project.
The width of all flashings is determined by the type of
accessory surrounding the window and where the final
complete course of siding stops below the window (in the
case of the flashing under the window). The flashing should
extend past the nail flanges of the accessory. The width of the
flashing under the window must allow for the diversion of
water.
NOTE: The flashing is long enough to direct water
over the nail flange of the last course of complete
siding panels.
Apply the vertical flashings by overlapping the previously
secured bottom flashing. As noted above, the length and
width of the flashings will be determined by the type of
accessories used.
Secure top flashing.
For even greater protection, make
a slit in the building wrap and
insert the top flashing behind it.
Tape the seam as shown.
rain tab
1"
1"
1"
1"
(1" or
dimension
of J-channel
face)
1"
1"
rain
tab
rain
tab
rain
tab
CertainTeed Vinyl Siding Installation Guide
36
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 the sides of the windows. Notch them as
shown.
NOTE: For best results, use aviation snips when cutting
J-channel.
Cut the top and bottom J-channels so the ends extend
beyond the casing to the width of side J-channels.
Place the 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 the side J-channel. Repeat for the other side.
This forms a water drain and allows the J-channel to receive
siding panel.
Nail the bottom J-channel in place. Cut the channel as
previously described. Fold the rain tabs into the 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 the 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 to form a rain tab,
position it 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 rain tabs. Position and nail.
3-1/2" Snap-on Lineal Application around
Windows and Doors
This application works only on 1"-faced J-channel .
The installation of J-channel for snap-on lineals is the same
procedure as installing lineal starter strip. Measure the
openings and cut the J-channel 1/2" less than your
measurement. Install the J-channel around the opening,
centering the J-channel so that each end of the J-channel is
1/4" from the opening. Nail the J-channel every 8" to 10".
Lineal application around windows
Measure the top of the casing and add 7" (3-1/2" extra for
each side). After the piece is cut to length, flip it over and cut
3/8" off the locking leg as shown.
Snap over the J-channel as shown.
Repeat the process for the bottom of the casing.
CertainTeed Vinyl Siding Installation Guide
37
CertainTeed Vinyl Siding Installation Guide
38
Measure the side casing and add 7". Use a triangle to create a
45° angle or measure 3-1/2" in from the edge of the part. Use
snips or a miter saw to remove this portion.
Flip the part over and remove the locking leg as shown. This
should be done to both ends.
Snap the lineal over the J-channel as shown. Use the same
measurements for both sides.
Corner blocks
Install J-channel around the perimeter of the window opening.
J-channel should be the same length as the casing.
Install corner blocks on all 4 corners as shown. Leave blocks
loose until the lineals are installed.
Cut the lineals the same length as the window casing.
Start with one end and angle a lineal into the corner block and
snap it over the J-channel.
Continue installing lineals around the window.
Crown molding
Crown molding will fit over the top of the lineal system.
Install J-channel and lineals around window casing.
Measure the top lineal and add 2-1/2". This will be the crown
molding length.
Insert crown molding cap into the crown molding and trace
the shape. Trim off the marked line.
The crown molding requires a tab 2" long – cut from the
pocket receiver as shown.
Cut the crown molding cap in half and apply the halves with a
bead of caulk.
Insert the crown molding into the top of the lineal as shown.
Lineal Starter Application for
Windows and Door Surrounds
When securing window and corner starter strips, outside
corner pieces (OSCP), inside corner pieces (ISCP), one piece
corners, lineals – basically, any vertically mounted siding
product – always place the top nail (or staple) first, and in a
manner that allows the part to hang from it without dropping.
This promotes movement downward only, a must for a good
corner joint. This is the only time you should not center a
nail (or staple). It is also preferred to use the nail slots closest
to the locking area (when using product with double nail slots).
Remember to place the nails for the horizontal pieces in the
center of the nailing slots as shown. Space nails 8"-10" apart.
Using a 1/2" J-channel as a starter for lineals.
NOTE: Slide the lineals on from either end of the
J-channel (the lineal will not snap over the J-channel
as with a New Construction Starter Strip), or pull the
J-channel away from the window slightly and zip the
lineal into place.
If the opening has no framework, such as a brick molding,
use the metal starter (illustrated below left), or the Remodeling
Window and Door Starter (illustrated below) in place of the
New Construction Window and Door Starter Strip shown
above. The lineal’s locking leg will fit behind the aluminum
starter and into the receiving pocket of the Remodeling
Window and Door Starter.
CertainTeed Vinyl Siding Installation Guide
39
measure window and subtract 1/2"
(leaving 1/4" per side as shown)
vertical pieces: place the uppermost nail
in top of nail slot (still loose nailed)
1/4"
1/4"
remaining vertical nails and all horizontal
nails: place in center of slots
window
or door
frame
1/2" J-channel
wall (substrate)
door opening
inverted
metal
starter
door opening wall (substrate)
position of nail
remodeling
window and
door starter
3-1/2"
window or
door frame
cut for rain tab
rain
tab
back-side view
of mitered lineal
45°
3-1/2"
remove
CertainTeed Vinyl Siding Installation Guide
40
Lineal Application around Windows
Measure the top of the opening and add 7" (3-1/2" extra for
each side) if the side lineals are also 3-1/2". Add 10" total if
using 5" lineals.
Use a triangle to create a 45° angle or measure 3-1/2" in from
the locking leg.
NOTE: The nail flange is always the longest part of a
surrounding miter.
Use snips to remove the part as shown.
Cut a 3/4" rain tab (as shown)
Snap the completed top lineal into the previously attached
starter strip.
NOTE: The bottom miter of side lineals has the same cut
as both ends of a top lineal.
Measure the height of the window or door. Add 7" (for
the 3-1/2" header and bottom lineal) and cut.
NOTE: Add additional material if using 5" lineals.
Trim a minimum of 3/4" from the top end of the side lineals.
Snap the side lineals into place, making sure the rain tabs of
the top lineal are bent down into the receiving pocket of the
side lineals.
If the lineal surrounds a window frame, the bottom corner
requires a 45° miter as done previously for the top lineal.
CertainTeed Vinyl Siding Installation Guide
41
window or
door frame
window
frame
rain tab shown bent into
receiving pocket of side lineal
view of above notches
from back side of lineal
1/2"
3-1/2"
3/4"
finished
assembly
with side
lineal
window
frame
view of
notching
from back
side (same on
both ends)
3-1/2"
3/4"
3/4"
CertainTeed Vinyl Siding Installation Guide
42
Measure the bottom of the opening and add 7" (3-1/2" extra
for each side) if the side lineals are also 3-1/2". Add 10" total if
using 5" lineals.
Trim 3/4" tabs from the lineal as shown.
Snap the lineal in place and secure by nailing (or stapling) it
through center of the nail slots.
Cut a section of lineal equal
in length to the face of the
lineal. This dimension is
dependent on the rake angle.
Using PVC cement primer
and cement on both pieces,
slide the part into the lineal
to create an assembly.
Apply the assembly to the wall and
secure it, nailing as necessary.
Lineals over Horizontal Siding
Capping a Lineal
Used as a Rake Board
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43
5" lineal
1/4"
flashing
new construction
starter strip
Butt dual undersill trim upward
against the bottom of the flashing
Hand punch horizontal siding
(locking area has been removed).
Siding panel locks into dual
undersill trim.
dual
undersill
trim
rosette clip
rosette center
(back side)
2-5/16"
2-5/16"
1/8" per side
make 1" cuts
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44
Corner Blocks
Corner Block
Install 1/2" J-channel as a starter. Measure and cut the side
lineals to the exact size of the window or door opening. Cut
the top and bottom lineals 1/4" longer than the window.
Using vinyl snips, make two 1" long cuts in the pocket areas
on both sides of each lineal. These cuts allow the lineals to
connect with the corner block and help provide proper
drainage.
NOTE: It may be helpful to hold off securing the lineals
until the corner block is in place.
Position the corner block by inserting the top lineal into the
corner block’s receiving area–making sure the lineal’s pocket
is inside that of the corner block.
Position the vertical (side) lineal into the corner block by
inserting the pocket of the corner cover into the pocket of the
lineal. This will ensure proper drainage.
Corner Block with Rosette
Locate the small dimple on the back side of the block’s face
or measure 2-5/16" as shown and mark.
Drill or punch a 3/32" - 1/8" diameter hole through the face of
the block – the hole must not be larger than 1/8".
NOTE: Check the back side of the block for this location –
marked by “+”.
Apply the rosette clip from the backside. If desired, a small
amount of caulk can be applied over the hole prior to applying
the rosette.
1-1/2" - 1-3/4"
slit in pocket
area of the
3-1/2" side
lineals
3-1/2"
1-1/8"
5" lineal
header
removing this
section allows
side 3-1/2" lineal
to slide behind
the 5"
2" rain tab
end cap
(from 5"
lineal)
3/4"
3/4" rain tab
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CertainTeed Vinyl Siding Installation Guide
5" Square Header with End Caps over
3-1/2" Lineals Sides and Bottoms
Assemble the 5" header and cap. The side 3-1/2" lineals
should extend approximately 1" inside the header assembly.
Finish the corner by sliding the 3-1/2" side lineals behind the
header, making sure the 2" rain tab on the end cap extends
into the receiving area of the side lineals.
NOTE: If using crown molding, see page 48.
3/4"
3/4"
3/4"
rain tab
2"
remove
remove
remove
CertainTeed Vinyl Siding Installation Guide
46
Creating End Caps for 5" Lineals
To create the header, first cut a 7" piece of 5" lineal. Measure
and trim as shown.
The resulting piece fits into the end of the 5" lineal.
The ends of the 5" lineal also need trimming to receive the end
caps. Create a 3/4" rain tab in the pocket area and trim off a
3/4" tab from the bottom.
NOTE: To make end caps for 3-1/2" lineals, simply start
with a 5-1/2" piece and remove the 3/4" and 2" areas as
shown for the 5" end caps.
Slip Joints for Lineal Corners
Assemble the 5" header and cap. The side 3-1/2" lineals
should extend approximately 1" inside the header assembly.
Finish the corner by sliding the 3-1/2" side lineals behind the
header, making sure the 2" rain tab on the end cap extends
into the receiving area of the side lineals.
CertainTeed Vinyl Siding Installation Guide
47
1-1/2" - 1-3/4"
slit in pocket
area of the 3-1/2"
side lineals
3-1/2"
1-1/8"
removing this
section allows
side 3-1/2" lineal
to slide behind
the 5"
5"
lineal
header
3/4" end cap
(from 5" lineal)
3/4"
3/4" rain tab
2" rain tab
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48
Crown Molding Treatment Options
Option 1 (page 49)
• Crown molding
• (2) crown molding end caps
• 3/4" pocket J-channel header and surround
Other options are possible with the crown molding: For
example, use 3-1/2" lineals vertically and at the window base
along with a J-channel and crown molding header. The only
requirement for using the crown molding is having receiving
channels 3/4" wide.
Option 2 (page 49)
• Crown molding
• (2) crown molding end caps
• 3-1/2" lineal header
• 3-1/2" lineal surrounds
NOTE: Corner blocks/rosettes can be used to join lineals
at the corner.
Option 3 (page 50)
• Crown molding
• (2) crown molding end caps
• 5" lineal header
• (2) 5" header end caps
• 3-1/2" lineal surrounds
Instructions for each option are on pages 49-51.
insert cap
(see above for instructions
on assembling the cap)
2" rain tab
2" rain tab
window
flashing
window
or door
frame
cut crown molding
cap in half
49
CertainTeed Vinyl Siding Installation Guide
Crown Molding and Cap for
3/4" Pocket J-Channel
You will need:
• Crown Molding
• (2) Crown Modling end caps
• 3/4" pocket J-channel header and surround
To use crown molding with 3/4" pocket J-channels,
measure the length of the completed J-channel surround
and add 2-1/2" (the crown molding overlaps the J-channels
by 1-1/4" per side).
Insert the crown molding cap into the crown molding and
trace the tip shape. Trim as shown.
Insert 1/2 of the crown molding cap into each end of the
crown molding lineal. Secure the crown molding with a bead
of caulk.
Miter or square cut the J-channel (mitered corner is shown).
Insert the 3/4" wide rain tab into the receiving channel of the
side J-channel.
Crown Molding with
3-1/2" Lineal Surround
In addition to J-channel, crown moldings can also be used
with lineals. The next two pages demonstrate how crown
molding can be used with various lineal configurations. Above
all, remember that before applying accessories and siding,
make certain the substrate is watertight. In order to be
properly protected from precipitation, the substrate may need
to be properly flashed to shed water to the exterior. The siding
alone is not a watertight barrier.
5" lineal header
1/16" - 1/8"
per side
2-1/4"
2"
3/4"
3/4"
window or
door frame
3-1/2" lineal
rain
tab
CertainTeed Vinyl Siding Installation Guide
50
Crown Molding with Cap for
5" Header Lineal
Crown molding with 5" header and
3-1/2" surrounds.
Determine the header length by measuring from the
outside of both side lineals and adding 1/16"-1/8" per
side for overlap.
To cut the crown molding, add 2-1/2"
to the previously determined header length (1-1/4"
added per side).
To create the header end cap, cut a 9-1/4" piece of
5" lineal and trim as shown.
Notch both ends of the header as shown.
Insert a crown molding cap into the crown molding and trace
the shape. Trim as shown.
Insert the header cap.
Cut the crown molding cap in half. Apply each half to the end
of the crown molding and secure it with a bead of caulk.
CertainTeed Vinyl Siding Installation Guide
51
the crown molding
requires a rain tab 2"
long – cut from the
pocket receiver
apply the crown
molding to the header
with a bead of caulk
rain tab to
divert water
from crown
molding to
side lineals
finished
assembly
Band Board
Installing Band Board
Before you begin, determine where the last course of siding
will end. Nail cornice receiver loosely every 8"-10", with the
nailing fin facing up. Keep the cornice receiver straight as it
establishes the line for the Band Board.
Install the last course of siding 1/4" below the cornice receiver.
If necessary, trim the top of the siding panel to fit below the
cornice receiver. With a nail slot punch, punch nail slots 16"
apart, 1/4" from the panel’s upper edge. Nail through the
center of the holes for a loose fit between the panel surface
and the nail heads.
Cut Band Board to length, allowing for clearance between the
Band Board ends and the trim for expansion and contraction.
Push the snap leg of the Band Board into the cornice receiver.
Nail the Band Board loosely every 10-12".
Fitting into trim pieces
The Band Board is designed to fit into CedarBoards J-Channel,
Corner, and lineal 1-1/4" accessories.
For lengths less than 12', allow 1/4" gap between the ends
and the trim at temperatures above 40° F; 3/8" gap at
temperatures below 40° F.
For lengths greater than 12', allow 3/8" gap between the ends
and the trim at temperatures above 40° F; 1/2" gap at
temperatures below 40° F.
When using the Band Board in installations with accessories
that DO NOT have a 1-1/4" pocket, be sure to allow clearance
between the two pieces for expansion. Trim a short section of
Band Board to create an end cap for these applications.
Installing siding above Band Board
There are two ways to continue siding above the Band Board:
• For horizontal siding, use a starter strip. Position the
starter strip above the Band Board enough to allow the
siding return leg to engage the starter strip.
• For vertical siding, use J-channel. Align the nail slots of
the J-channel with the nail slots of the Band Board.
NOTE: When nailing a starter strip, avoid pinning the
Band Board. The Band Board must be allowed to expand
and contract freely.
52
CertainTeed Vinyl Siding Installation Guide
nail with fin facing up
push snap leg of band board
into cornice receiver
Overlapping two pieces of Band Board
Only factory-cut edges can be used create a lap seam. The
adhesive begins approximately 2" back from the end of the
foam.
For the underside piece, measure back 1-1/2" from the end of
the vinyl. Cut back 1-1/2" of foam and remove the bottom
portion of the rear return and snap leg. Slip the vinyl edge of
the bottom portion of the seam between the foam and the
vinyl panel. Slide two pieces together, overlapping them
1-1/4", leaving a 1/4" gap between the foam for expansion.
Blind Miter
An alternative to a standard blind miter offers support to the
corner without adding material. The measurements shown
for the fold are for a 5" lineal. The same method can be used
with 3-1/2" lineals, but the fold would be changed from 1-1/2"
to 1-3/8".
CertainTeed Vinyl Siding Installation Guide
53
45°
Measure at
least 1-1/2"
and notch
with snips
Measure
and
notch 1-1/2"
Dotted line
represents
the position
of a 45°
mitered
5" lineal
Remove this corner
(dimension dependent
on 1/2" minimum shown
below)
3/4"
Installing Lineal Frieze Board
54
CertainTeed Vinyl Siding Installation Guide
5" lineal
lineal
starter
cornice
receiver
cornice
molding
1/4"
1/4"
panel
Installing J-Channel as Gable End Trim
Install J-channel to receive siding at gable ends, as shown
in the illustration. To create a clean, professional look, follow
these steps:
To create an angle template, hold a piece of J-channel against
the slope while transferring the angle to another J-channel
with a pencil.
Next, transfer the angle of the template to the end of a length
of J-channel. Be sure to extend the line onto the nail flange.
Cut away the channel face and the nail flange.
Turn the pattern over and transfer the opposite angle to the
second J-channel, being sure to extend the line onto the nail
flange. Cut away the nail flange and return lip, but do not cut
the J-channel face.
Insert the full-faced J-channel into the mitered J-channel. If
the nail flange or return lips butt and prevent a tight fit, trim off
additional material from the second J-channel.
NOTE: For a more decorative appearance, you also can
use 3-1/2" or 5" lineals to trim gable ends (see next page
for details).
To splice the J-channel, follow these steps:
Cut out a 1" section of the nailing flange and face return as
shown.
Install inverted J-channel along the top of the wall, under the
eave. Here again, leave a 1/4" gap between the J-channel and
the cornerposts. Overlap the J-channel 3/4" to allow for
expansion. When positioning the upper J-channel, be sure to
allow for expansion of the siding panel. In most cases,
position the J-channel at a point equal to the length of the
panel plus 5/8" (1/4" for upper expansion and 3/8" for lower
expansion).
CertainTeed Vinyl Siding Installation Guide
55
90°
90°
1"
3/4"
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 would subject it to a buildup
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".
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CertainTeed Vinyl Siding Installation Guide
90°
starter strip
1/2" (min.)
90°
Using Restoration Millwork® in Place of
Vinyl Accessories
To install outside corners
Flash the corners of the home by bending a 20" wide piece of
aluminum trim coil 90° so you have two 10" legs. Cover the
entire length of the corner, lapping the upper pieces over the
lower pieces. (Self-adhering flashing may be substituted for
trim coil. Follow manufacturer’s installation instructions and
observe local building code requirements.)
Position the outside cornerpost with the top of the post 1/8"
from the underside of the eave and the bottom of the
cornerpost 3/4" below the starter strip. Make sure posts are
straight and true before fastening. For advice regarding
fastening, please refer to document Restoration Millwork
Installation Guidelines (RM003), available online or where
Restoration Millwork is sold.
NOTE: It may be necessary to shim or furr out the corners
and/or window casings to get the proper pocket height.
Always use shimming/furring materials, like Restoration
Millwork, that will not rot or decay.
To install Trimboards around windows
Flash the window according to the manufacturer’s
specifications. Once the opening is properly flashed, begin by
measuring the width of the bottom edge of the window and,
using this measurement, cut the first section of Restoration
Millwork. Apply this piece to the bottom of the window,
verifying each end of the section lines up with the edge of the
window prior to fastening.
To determine the length of the trim along the sides of the
window, measure each side of the window starting at the top
of the window and dropping down to the bottom edge of the
first piece of millwork applied. Using these measurements, cut
the second and third sections of Restoration Millwork. Apply
these pieces to the left and right sides of the window, verifying
that the top edge of each section lines up with the top of the
window and the bottom edge of each section lines up with the
bottom edge of the first piece of trim already applied.
To determine the length of the top piece of trim, begin at the
left side of the left piece of trim and measure to the right side
of the right piece of trim. This measurement should equal the
width of the window plus two times the actual width of the
trimboards being applied. Cut the final piece of trim and apply
it at the top of the window, again verifying that the left and
right edges of the cut section line up with the left and right
edges of the trimboards in place at the sides of the window.
Once the top section of millwork is in place, apply flashing in
compliance with local building codes.
CertainTeed Vinyl Siding Installation Guide
57
shim corners to create
proper pocket height
optional J-pocket
measure
width of
window for
first piece
top of
window
bottom
of trim
measure from
left side of
trim to right
side of trim
flashing
flashing
To install Trimboards around exterior doors
Flash the door according to the manufacturer’s specifications.
Once the opening is properly flashed, begin by determining
the length of the trim along the sides of the door by measuring
each side. Start at the top of the door and drop down to the
desired termination point. Using these measurements, cut the
second and third sections of Restoration Millwork. Apply these
pieces to the left and right sides of the door, verifying that the
top edge of each section lines up with the top of the door.
To determine the length of the top piece of trim, begin at the
left side of the left piece of trim and measure to the right side
of the right piece of trim. This measurement should equal the
width of the door plus two times the actual width of the
trimboards being applied. Cut the final piece of trim and apply
it at the top of the door, again verifying that the left and right
edges of the cut section line up with the left and right edges of
the trimboards in place at the sides of the door.
Once the top section of millwork is in place, apply flashing in
compliance with local building codes.

NOTE: If the window or door you are trimming has a
nailing flange, you may have to shim the outside edges of
the trimboards to get them to lay flat. Failure to use shims
may result in an uneven look.