Installation Guide

1. FLASHING
Before installing siding, make sure that ashings are installed to prevent moisture from entering wall and roof
spaces. Flashing is an important line of defense in controlling moisture in wall assemblies. Flashing intercepts and
directs the ow of water away from the building to designed drainage paths. Install horizontal ashing extending
from the top of all wall penetrations (i.e. all windows and doors) and at any material or material directional change
(i.e. bandboards, water tables or the introduction of any alternative material). The ashing should tilt downward
to allow water to drain away from the wall. Siding or trim should be ¼” above the ashing ledge. Do not caulk
where the ashing and trim or other materials meet. Note that caulking in lieu of ashing is not acceptable.
Door and Window Flashing
The purpose of ashing window and door headers is
to intercept water behind the siding and direct it to the
outside, and to redirect water owing down the face of
the wall to ow away from the wall opening.
Moisture can accumulate behind the siding as a result of:
• rain penetration through the siding;
• water vapor diffusion;
• leakage of moist air from the interior or condensation.
Some moisture will drain through the weepholes at the bottom of
windows. An additional head trim ashing is required
at the head of the window/door to direct water further outward,
beyond the thickness of the window
Skirt and Bandboards
Ground Level Skirtboard Second Story Bandboard
INSTALLATION
9
SECTION II INSTALLING WESTERN RED CEDAR SIDING
Ensure Minimum
of 6” Ground
Clearance