How to Install Horizontal Siding

This chapter includes basic instructions for installing
CertainTeed vinyl siding. (These guidelines should not be used
to install Cedar Impressions®, Northwoods™, or CedarBoards™,
products, which are featured in Chapter 11 of this manual.)
For more detailed instructions, refer to the CertainTeed
Installation Guide (CTS205). These instructions describe and
illustrate the steps involved in installing CertainTeed siding and
trim. Their purpose is to provide detailed information and howto
tips that will simplify the installation process. CertainTeed
shall not accept any liability or responsibility under its written
warranty for failure caused by application that does not meet
the requirements for proper installation. These requirements
are outlined throughout this book and in the Installation
Guide. Any deviations from these requirements should be
addressed and approved in writing by CertainTeed Corporation.
Tools
• Chalk line
• Hacksaw
• Hammer
• Level
• Shears
• Square
• Tape measure
• Tin snips
• Utility knife
• Circular saw—attach a
sharp, fine-tooth plywood
blade mounted in reverse
direction
• Ladders and scaffolds—cushion
the upper side rails of extension
ladders to prevent damage
during installation
• Nail slot punch—use to punch
elongated nailing holes in the cut
edge of a panel
• Snap lock punch—use to punch
locking tabs in the cut end of a panel
• Zip tool—“unlocks” installed panels so
they can be removed from a wall
Wall Preparation and Sheathing
Vinyl siding must be applied over a rigid sheathing that provides
a smooth, flat surface or an underlayment that is no more than
1" thick. Do not apply vinyl siding directly to studs. Vinyl
siding is an exterior cladding; it is not a complete weather
resistant barrier.
New Construction
Fasten the sheathing securely to the studs. Make certain the
substrate is watertight.
To apply conventional house wrap or building felt, follow the
manufacturer’s directions. Secure the house wrap or felt
securely to the substrate. The surface must be smooth and even.
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CertainTeed Vinyl Siding Master Craftsman Education & Development Program
9. How to Install Horizontal Siding
Objectives
In this chapter you’ll learn proper techniques for installing
horizontal siding:
• Sheathing and wall preparation
• Proper cutting and nailing
• Installing trim
• Flashing around windows, doors, and the roof line
• Hanging the siding
• Attaching shutters and external fixtures
cut off and
discard
Remodeling
If you are covering old siding, there are three ways to prepare
the surface of the building for the new siding.
1. Strip off the old siding and level the wall. If there is felt
under the old siding, either nail it securely to the wall or
strip it off completely. If there is no solid sheathing under
the siding, you will have to install it. See New Construction
for details.
2. Apply rigid sheathing over the old siding. Nail it securely
and evenly, taking care to bridge the low spots.
3. Nail vertical furring on top of the old siding. Apply
rigid sheathing to the furring just as you would for
New Construction.
Stucco
If you are applying
siding to stucco, you
will have to create
an even, solid
surface to attach
the siding to.
• Carefully chip the
high spots off the stucco. Be
careful not to crack the stucco.
• Fasten 1" x 3" furring strips, 16" on center, over the stucco.
Use ring-shanked nails or screws, and attach the fasteners to
the studs.
• Install rigid foam sheathing to the furring strips. Follow the
manufacturer’s instructions, and use washers to prevent
penetrating the sheathing with the nail heads.
Fastening
Use only corrosion-resistant
fasteners (aluminum, galvanized,
or stainless steel roofing nails,
staples, or screws) with a
minimum head diameter of
5/16" and a minimum shank
diameter of 1/8". To determine
the length of the fastener you’ll
need, measure the thickness
of the sheathing and add 1".
Do not use fasteners smaller
than 1-1/2".
Fasteners are typically spaced a maximum of 16" apart. In new
construction, fasten 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. Check your local
building code for special requirements.
When installing horizontal accessories and panels, set the
fasteners in the center of the elongated nailing slots. Drive the
fasteners straight in; do not angle them). Also, do not
fasten too tightly. Drive the fasteners until there is up to 1/16"
of space between the fastener head and the nailing flange. This
will allow the panels to expand and contract as the temperature
changes. If the
height of the
fastener head is
more than 1/8"
above the nailing
flange, it can
interfere with the
locking tab on the
next row of siding.
For vertical accessories and
panels, position the first
fastener at the upper edge of
the top-most nailing slot.
This will allow the panels to
hang freely from the
fasteners and expand and
contract as the temperature
changes. Position the remaining fasteners in the center of the
nailing slots. Allow for 1/3 of the total expansion at the top of
the panel and 2/3 at the bottom.
STUDfinder™ Installation System
STUDfinder™ Installation System combines precisely engineered
nail slot locations with graphics to create a siding panel that is
designed to help ensure quick, accurate and secure installation.
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CertainTeed Vinyl Siding Master Craftsman Education & Development Program
center
of all
slots
16"
1/8" to 1/16"
too tight too loose correct
upper edge of topmost
nailing slot
16"
stucco
1 x 3 furring
ring-shanked
nails for
attaching furring
foam sheathing
The nail slots are positioned 16" and 24" on center (o.c.) to
allow for alignment with studs, with STUDfinder™ graphics
centered directly under each nail slot. This provides a quick
and easy guide to help ensure fastening to studs.
Here’s how it works:
1. Locate the first stud and fasten in the center of the nail slot.
Notice which STUDfinder letter appears below the slot. Check
that nail/staple penetration is at least 3/4".
2. Simply go to the next repeat of the letter to find the next stud.
For example, if your first stud is at “T,” so will the succeeding
studs in 16" o.c. applications (every 10th slot). When
installing 16' or 20' Monogram 46L or Cedarboards XL
16' 8" panels on 16" centers, the succeeding studs are at
every 8th slot.
3. When you apply the next panel, adjust the overlap, as
necessary, to line up with studs and repeat steps 1 and 2.
4. Each panel will use the same letter in 16" o.c. application.
5. 24" o.c. applications will use a similar pattern of letters, with
2 letters that repeat every-other stud (every 15th slot). For
example, if the first stud is located at “S,” the next will be at
“I,” then “S,” then “I,” etc. When installing 16' or 20'
Monogram 46L panels on 24" centers, the succeeding studs
are at every 12th slot.
NOTE: When lapping horizontal panels up to 12' 6",
overlap the ends 1". Panels longer than 12' 6" must be
overlapped 1-1/2".
Expansion and Contraction
Vinyl building products expand and contract as the temperature
changes. You must allow for this movement when you fasten
siding and accessories to the wall. Follow these guidelines to
determine the space required for expansion and contraction
between the siding and the trim:
• In a horizontal
application, a vinyl panel
tends to expand equally in
both directions, so when
the temperature is warmer
than 40°F at the time of
installation, leave 1/4" at
both ends of the panel.
• When the temperature is below 40°F at the time of application,
leave 3/8" at both ends of the horizontal panel.
• In a vertical
installation, most
of the expansion is
downward. So,
instead of allowing
equal space for
expansion at both
ends, leave more
space at the lower
end. Allow for 1/3
of the expansion at
the top and 2/3 at
the bottom.
• In a vertical installation, if
the temperature is below
40°, allow 1/4" at the top
and 1/2" at the bottom.
• When overlapping
horizontal panels, overlap
the ends 1".
Cutting
To cut panels to size, make either cross cuts or rip cuts. Note:
whenever you cross cut a panel that is used in an overlap area,
duplicate the factory notch at the cut end.
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CertainTeed Vinyl Siding Master Craftsman Education & Development Program
16"
24"
1/4" to 3/8"
1"
1/3 total expansion
topmost
nail at the
top of the
topmost
nail slot
center
remaining
nails in
the slots
2/3 total expansion
Cross Cuts with a Power Saw
• For a precise cut, use a power circular saw equipped with a
sharp, fine-toothed plywood blade. For best results, reverse
the direction of the blade.
• Cut one or two panels at a time.
• The lower the outside temperature, the lower your feed rate
should be.
Cross Cuts with Snips
• Use a square to mark the cut line.
• Start the cut at the top lock and
continue to the bottom of the panel.
Rip Cuts
• Use a utility knife to score the panel
along the cut line.
• Bend the panel back and forth along
the score line until it snaps cleanly.
• To fit panels around windows and
doors, cut the panels with tin snips and a utility knife.
Installing Accessories
Snap a Chalk Line
If the house is reasonably level, find the lowest point
of the sheathing (in new construction) or old siding
(when remodeling).
1. Partially drive a nail at one corner, starter height minus
1/4" above the lowest corner.
2. Attach a chalk line.
3. Stretch the chalk line from this nail to the opposite corner
of the house.
4. Use a line level or 4' (minimum) level to make sure the line
is level.
5. Snap the chalk line and repeat the entire procedure around
the entire house.
A laser level or water level, a long clear plastic tube 90% filled
with water, is useful in marking points around the house and on
opposite sides of openings like doors.
Install a Starter Strip
Correctly installing a level starter strip is the first step to a
professional installation.
1. Position the starter strip with the top edge on the chalk
line. If you are using lineals or wide corners, keep the
ends of the starter strip 6-1/2" away from the outside and
inside corners. Keep the ends 4" away from standard
one-piece corners.
2. Fasten the strip to the wall. If there are hollows in the
wall, shim out the starter strip. This will prevent a wavy
appearance in the finished job.
3. As you add starter strip sections, be sure to leave 1/4"
space between them for expansion.
Outside Cornerposts
Before you install outside cornerposts, flash the corners of the
building 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 of the flashing over the lower pieces.
(Self-adhering flashing may be substituted for trim coil. Follow
manufacturer’s installation instructions and observe local
building requirements.)
1. Position the top of the outside cornerpost 1/4" from the
underside of the eave. The bottom of the cornerpost should
fall 3/4" below the starter strip.
2. Remove the bottom 3/4" of the nailing flange so it will not
show below the siding when it is installed.
3. Make sure the cornerpost is straight and true before
you nail it.
CertainTeed Vinyl Siding Master Craftsman Education & Development Program
6-1/2"
for wide
corners
and lineals
4" for
standard
corners
chalk
line
8"–10"
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factory notches
4. Hang the cornerpost by first positioning a nail at the
topmost part of the top nail slot. Position all the remaining
nails in the center of the nail slots a maximum of 8" to 10".
Follow this pattern on both nail flanges of the posts.
5. Leave 1/8" to 1/16" between the nail head and the
cornerpost to allow the cornerpost to move during
expansion and contraction.
NOTE: When installing Traditional, Beaded, and Super-
Corners™, or hanging any cornerpost longer than 12',
position the fasteners at the top of the top two nail slots
on each side of the corner. As you work your way down
the corner, position the rest of the fasteners in the
center of the nail slots.
If you must splice posts
for high walls, 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. Allow 1/4" for
expansion. There will be
an obvious joint between
the two posts, but water
will flow over the joint
and be less likely to
infiltrate behind the post.
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CertainTeed Vinyl Siding Master Craftsman Education & Development Program
1/4"
1"
1/4" to 3/8"
hang from two nails,
center remaining nails
flashing
3/4"
nail every 8" to 10"
3/4"
1/4" to 3/8"
hang from top nail,
center remaining nails
flashing
CertainTeed Vinyl Siding Master Craftsman Education & Development Program
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Inside Corner Options
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:
1. Bend a 20"-wide piece of aluminum coil stock 90° so you
have two 10" legs.
2. 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:
1. Hang the post from the top of the eave. The bottom should
extend 3/4" below the starter strip.
2. Remove the bottom 3/4" of the nailing flange so it does not
show below the siding.
3. Set the post straight and true.
4. Position the top nail in the top of the nailing slot. All other
nails should be in the center of the nail slots.
If you have to splice the inside cornerpost:
1. Cut 1" off of all but the outer face of the lower post.
2. 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 6" x 6" “L” corner
fabricated from aluminum coil stock. 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.
standard 3/4" inside
cornerpost
single J-channel
(when using a single J-channel,
the corner must have corner flashing)
corner flashing
(scrap aluminum
coil, for example)
solid nailable
substrate
two J-channels
inside cornerpost splice
Trim at the Roof Line
There are places where vinyl siding and accessories will meet
at a roof line. These areas will be trimmed with J-channel.
However, if you install the J-channel directly on the roof, it can
build up an excessive amount heat. This heat might cause the
J-channel to expand excessively. Therefore, at these places—
like where a gable dormer or second-story side wall intersect
with the roof—position the J-channel so it is a minimum of 1"
away from the roof line. Also, if you use more than one length
of J-channel to span a wall surface, overlap the J-channels 3/4".
To keep water from infiltrating along the intersection of the roof
and wall, install flashing before you install J-channel.
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.
All windows must be properly flashed before you install trim.
Before you begin, determine the width and the height of the
flashing. There are three things that determine these important
measurements:
1. The type of accessory
surrounding the window—the
flashing should extend past the
nail flanges of the accessory.
2. Where the final complete course
of siding stops below the
window—the flashing must be
wide enough to divert water over it.
3. The height of the window—the flashing should be long enough
to divert water over the nail flange of the last complete course of
siding panels and extend up under the top flashing.
Window and Door Trim
To trim windows and doors, install J-channel along the top and
sides of the door casings and around windows.
If you are installing J-channel around replacement windows
that do not have nail flanges, flash the window before you
trim it. Also, for best results, use aviation snips when cutting
the J-channel.
Before you begin to miter the corners, make sure the
J-channel is cut to the proper length. Leave the proper
allowance for the width of the face of the J-channel. Then:
1. Square cut the bottom J-channel so that its ends extend
beyond the window casing to the width of the face of the
J-channels.
2. Notch the ends for clearance.
3. Position and fasten the bottom J-channel.
4. Measure the side J-channels. Add the width of both
the top and bottom J-channels.
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CertainTeed Vinyl Siding Master Craftsman Education & Development Program
minimum 1"
5. Miter cut (45°angle) the lower ends
of both side J-channels.
6. Notch the channels,
position them, and
fasten the side
J-channels.
7. Mark the top
J-channel so its
ends extend beyond
the casing to the width
of the side J-channels.
8. Miter cut (45° angle)
the channel ends.
9. Cut and bend water tabs
on the J-channel.
10. Position and fasten the top J-channel.
Installing Horizontal Courses
The key to creating a visually attractive installation is to avoid
using panels that are shorter than 3' and to lap away from the
areas where people normally walk or gather.
• On the front wall, work from the corners to the entrance
door, so the overlaps face away from the door.
• On side walls, work from the rear to the front.
First Course
To install the first horizontal course:
1. Slide the first panel into the cornerpost recess.
Leave room for expansion.
2. Hook the bottom lock of the panel into the interlock
bead of the starter strip. Double check to make sure
you’ve locked the panel along its entire length. You may
need to apply a light upward pressure to snap the panel
securely in place.
3. Make certain the panel can slide freely.
4. Start at the center of the panel and work out, and
fasten the siding to the substrate.
5. Install the remaining first course panels, overlapping the
panel ends 1".
6. To allow for a neat lap, the last fastener in the panel should
be at least 4" from the end.
7. Remember to leave room for expansion when fitting the panels
into the remaining inside and outside cornerposts.
Subsequent Courses
For the best appearance, plan the positioning of the panels to
avoid unsightly joint patterns. Follow these guidelines:
• Separate joints by at least two courses.
• Avoid joints above and below windows.
• Leave at least 3' separating joints on successive courses.
• Use short cutoff lengths at narrow openings before windows.
• Follow your pattern through all the courses.
CertainTeed Vinyl Siding Master Craftsman Education & Development Program
25
room for
expansion
lock panel to
starter strip
(1" or
dimension
of
J-channel
face)
rain tab
1"
1"
rain tab
lock not fully
engaged
lock fully
engaged
1"
Fitting under Windows
To fit siding panels under windows:
1. Hold the panel in place and mark the width of the window
opening. Add 1/4" to 3/8" to both ends to allow for
expansion and remark the panel. These marks are the
location of the vertical cuts. Extend the marks onto the
panel using a square.
2. Create a template for the horizontal cut with a piece of
scrap siding. Lock the scrap piece into the lower panel and
mark 1/4" below the sill height. This will provide clearance
for the undersill trim. Because the window may not be
perfectly level, repeat this procedure on the opposite side of
the window.
3. Transfer the marks from your template onto the panel. With
a straightedge to guide you, connect the marks.
4. Cut the panel. Use tin snips to make the vertical cuts and a
utility knife to make the horizontal cut.
Installing under Windows
If it is necessary to maintain
the slope angle, install furring
under the sill or use dual
undersill trim. This trim has
two receiving channels. Use
the inner channel if you’ve cut
the siding panel near the
locking edge. Use the
outer channel if the cut
has been made near
the butt edge.
1. Use the snap lock punch
to raise tab faces on the
outside of the panel. Punch out a tab every 6".
2. Push the horizontal edge of the cut into utility trim. Slide the
vertical edge of the cut into J-channels at the window sides.
Make certain the installed panel locks into the panel below.
Fitting over Windows and Doors
The procedure for cutting panels for installation over windows
and doors is similar to that explained earlier.
1. If it is necessary to maintain the slope angle, install furring
above the window.
2. Drop the panel into position, making certain that it fits into
the undersill trim and J-channel at the top and at the sides.
Interlock the panel with the siding panels below.
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CertainTeed Vinyl Siding Master Craftsman Education & Development Program
1/4"
1/4"
window
J-channel
utility trim
horizontal
siding
dual
undersill
trim
Fitting Narrow Openings Between Windows
When you install siding in the narrow openings between
windows, be sure to leave adequate tolerances for expansion
and contraction.
To simplify installing siding
panels in the narrow openings
between windows, install
J-channel on both sides of the
opening. Bow the panel toward
you and slip it into the channel.
If the channel is very narrow,
leave one J-channel loose except
at the lowest point. Bend the
channel out slightly to insert the
panel. When the panel is in
place and fastened, fasten the
J-channel immediately above the
panel and repeat the procedure.
Fitting at Gable Ends
Before you begin to install panels on a gable end, you will have
to make a pattern duplicating the gable slope. Use this pattern
to guide the cutting of the panels to fit the gable ends. To make
the pattern:
1. Lock a short piece of siding into the panel starter strip as
shown in the illustration.
2. Hold a second piece of siding against the J-channel on the slope.
Run a pencil along the edge of this piece, transferring the slope of
the angle to the first piece of siding.
3. Cut along the line using a power saw or tin snips. Use this
pattern to mark the siding panels before cutting them.
To install the cut panels:
1. Slip the angled end of the panels into the J-channel along
the gable edge. Leave space for expansion.
2. Interlock the panel with the course below.
3. It may be necessary to fasten the last panel to the top of the
gable peak. If so, use a 1-1/4" to 1-1/2" aluminum or
stainless steel trim nail with a painted head to face nail the
panel. This is the only time you will face nail vinyl siding.
Fitting under Soffit
When you reach the last course of siding, you will probably have
to rip cut the panels lengthwise to fit the panels under the soffit.
Once again, if it is necessary to maintain the proper slope angle,
furr out the area.
1. Install J-channel and undersill trim or dual undersill trim.
2. Measure from the soffit to the base of the upper lock on the
course of the panels below. Subtract 1/4".
CertainTeed Vinyl Siding Master Craftsman Education & Development Program
27
colored
aluminum
finish nail
distance minus 1/4"
3. Mark this dimension on the panel to be cut, taking the
measurement from the bottom edge of the panel. For a
more precise cut, repeat this procedure at several other
points along the span to be covered by the panel.
4. Using a square or straightedge, draw a pencil line
connecting these points. Then score along the line with a
utility knife. Bend the panel back and forth until it snaps.
5. Use the snap lock
punch to create tabs on
the outside face of the
panel, 1/4" below the
cut edge. Space the
tabs every 6".
6. Lock the bottom of the
cut panel into the
panel below.
7. Push the top edge into
the undersill trim. The tabs will catch in the trim and hold the
panel firmly in place. You will not fasten this last course, so it
is important that the tabs fit properly in the undersill trim.
Attaching External Products
All external products (downspouts, shutters, lights, for example)
are attached to walls after you’ve installed the vinyl siding.
• All external fixtures must have a secure mounting surface.
They must be attached to a solid backing, such as 3/4"
exterior grade plywood.
• Never attach a fixture directly to vinyl siding.
• Allow for expansion and contraction of the siding under the
accessory.
• Drill holes in the siding three times the diameter of the
screws, bolts, or nails being used to fasten the objects.
• Do not fasten screws, bolts, or nails tightly.
Lights
The most convenient way to attach light fixtures is with light
blocks. Light blocks provide a simple way to allow for
expansion and contraction because they contain receiving
channels to hold the siding panels.
Shutters
(A) The ideal application has a joint between the two shutters
where the shutters are secured to the house. In this way,
the siding panel is not hard fastened between the two
shutters and the siding can expand or contract.
(B) When there is no joint between the shutters where the
shutters are secured to the home, the shutter fasteners
keep the siding panels from moving freely.
• Enlarge the hole in the siding for securing the shutter.
The hole clearance should be approximately 1/8".
• If possible, stagger the screws on the shutter so that they
do not line up on the same panel.
• Apply caulk around the screws.
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CertainTeed Vinyl Siding Master Craftsman Education & Development Program
(A)
(B)
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CertainTeed Vinyl Siding Master Craftsman Education & Development Program
Summary
• Vinyl siding must be installed over a rigid sheathing that
supplies a smooth flat surface. Use furring or shims to
correct uneven walls.
• In general, fasteners must be spaced no more than
16" apart.
• Vinyl siding expands and contracts as the temperature
changes. Fastening the siding too tightly prevents the siding
from moving freely. Fasteners that are too loose will interfere
with the locking hem.
• Flashing should be installed at the roofline, on inside
corners, and around all windows and doors before siding
is installed.
• For the best appearance, position the siding panels to
avoid unsightly joint patterns. Follow the pattern for the
entire installation.
• Do not install panels that are shorter than 3'. On the front
wall, work from the corners to the front door. On side walls,
work from the rear to the front.
• Shutters, lights, and other exterior products are attached
to the walls after the siding has been installed. Exterior
products must have secure mounting surfaces and they
must never be attached directly to the siding.
• Accessories that are used with insulated siding should be
backed with foam shims and fillers to ensure that the siding
and accessories are on the same plane.
• Wood shims and/or aluminum trim coil or vinyl lineals can
be used to build out windows, doors, and other openings in
insulated siding.