Installation Instructions

CertainTeed Vinyl Siding Installation Guide

SECTION 6 — Preparing 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. See the instructions on page 29 for installation over

continuous insulation systems thicker than 1".

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. See page 45 for proper ﬂashing around windows.

The siding alone is not meant to be a watertight barrier.

Vinyl siding cannot be installed on a radius wall.