Installation Guide

Western Lumber Grades
for Siding Products
Western Wood Products Association
522 SW Fifth Avenue, Suite 500
Portland, OR 97204-2122
503-224-3930 fax: [phone]
e-mail: [e-mail]
website: www.wwpa.org
TG-8/0717/Rev.7-07/5M
©2007 WWPA
Photocopy this chart and post in a convenient place.
GRADES
7
Grade Rule Paragraph
WESTERN SPECIES CEDAR
Numbers for
Western &
Refer
ence & Specifying
Selects
1
Finish Canadian WWPA
2
WCLIB
3
NLGA
4
Clear Heart
5
20.11 102-b 200a
A Grade
5
20.12 102-c 200b
C Select
5
10.12 – –
Superior 10.51 – –
D Select
5
10.13 – –
Prime 10.52
––
B Grade 20.13 102-d 200c
Clear VG Heart
5
21.11 106-aa 201a
A Bevel
5
21.12 106-a 201b
Superior Bevel 16.11 – –
B Bevel 21.13 106-b 201c
Rustic – –
201d
C Bevel 21.14 106-c 201e
Prime Bevel 16.12 – –
Select Knotty
6
––205a
Quality Knotty
6
– – 205b
Commons
1
Alternate
Boards
2 Common Select Merch. – 30.12 118-a 114a
Construction Select Knotty
6
– 111-e 204a
3 Common 30.13 118-b
8
114b
8
Standard Quality Knotty
6
– 111-f 204b
118-c
9
114c
9
All Patterns
All Patterns
Knotty
Premium
Knotty Grades
Premium Grades
Additional Grades for
Bevel Patterns
1 Equivalent grades, under the same paragraph numbers in WWPA Rules, are available in Idaho White Pine. Refer to
Western Lumber Grading Rules.
2 Western Wood Products Association’s Western Lumber Grading Rules.
3 West Coast Lumber Inspection Bureau’s Standard Grading Rules for West Coast Lumber.
4 National Lumber Grades Authority’s Standard Grading Rules for Canadian Lumber.
5 Some clear grades may be specified VG (vertical grain). Common practice is to ship orders as a combination of verti-
cal and flat grain, unless specified otherwise.
6 The widely used marketing term, “STK” usually describes a combination of Select Knotty and Quality Knotty, some-
times marketed with approximately 15% of the order in Quality Knotty.
7 The grades listed in these three columns are arranged in order of highest to lowest appearance quality; Clear Heart
is the highest, and Standard and Quality Knotty are the lowest grades in this table.
8 Construction grade paragraph reference number.
9 Standard grade paragraph reference number.
The grade names in bold face type are the most widely available grades. These are often specified as a
grade combination that includes some portion of material in the next higher grade; i.e. C&BTR Select, D&BTR Select,
A&BTR Cedar, 2&BTR Common, 3&BTR Common or STAND&BTR (Standard & Better).
General
Categories
(Note that there
are additional
grades for bevel
pattern.)