Installation Guide

9
EXTERIOR NEW WALL CONSTRUCTION
Design and Application Instructions
Staggered Butt Coursing
For single course application, an attractive
effect can be made by staggering the butt of
the Certi-label Western Cedar shingle from
the horizontal line. Apply the Certi-label
Western Cedar shingle irregularly at variable
distances below (but not above) the
horizontal line.
Staggered butt applications are made by
shortening the exposure less than the
greater maximum exposure. No Certi-label
Western Cedar shingles or shakes shall be
applied greater than the maximum exposure
allowed. Check with local building codes for
approval of the staggered butt coursing
installation method.
Note: Keyway spacing-between Number 1
Grade Certi-label Western Red Cedar
shingles shall be 1/8” – 1/4”; Yellow Cedar
shingles shall be 1/4” - 3/8”.
Ribbon Coursing
A double shadow line effect can be obtained
by raising the outer course Certi-label
Western Cedar shingles approximately 1"
above the undercoursing. Use Number 1
Grade Certi-label Western Cedar shingles for
undercoursing when applying ribbon
coursing (Figure 11).
Architect: Alfredo De Vido Associates, Photo: Paul Warchol
Butt nail all double coursed Certi-label Western
Cedar shingles that are exposed more than their
maximum single course exposure.
Figure 10: Staggered Coursing
1" max. for 16" &18"
Certi-label Western
Cedar shingles
1 1/2" max. for 24"
Certi-label Western
Cedar shingles
Double starter course
The outer course is applied 1/2" lower
than the inner course as a drip course
to help shed water
Plywood panel
or dimensional
lumber sheathing
Plywood panel
or dimensional
lumber sheathing
Figure 11: Ribbon Coursing
The outer course is applied 1/2" lower
than the inner course as a drip course
to help shed water
Double starter course
Finished course
Underlayment shall
be No. 30 felt
conforming to
ASTM D226 Type II
or ASTM D4869
Type IV.
Underlayment shall
be No. 30 felt
conforming to
ASTM D226 Type II
or ASTM D4869
Type IV.