skip to main content

Lumber grading rules are a set of criteria used to determine how various characteristics, such as wane or knots, affect the structural performance of dimension lumber or the aesthetic value of Appearance Grades. Lumber manufacturers are responsible for grading the lumber to these rules and WWPA, as part of the American Lumber Standards system, helps assure that Western lumber meet stated product quality standards. 

WWPA - Western Wood Products Association a trade association representing softwood lumber manufacturers in the 12 Western states, from the Canadian border south to Mexico and from the West Coast to the Black Hills of South Dakota with services in Alaska, is the leader in the West in lumber grading, rules writing and quality control inspection.

BUYER BEWARE WARNING: The pattern measurements below are WWPA industry standards. HOWEVER individual mills often have their own pattern standards which vary from the norm (usually smaller). When you get ready to buy be sure to ASK for the exposed width to make sure you are buying enough SQFT of cedar siding to complete the job!

WWPA LAP Siding Pattern Diagrams

(1) COVE/GERMAN/DUTCH LAP SIDING - PATTERN 105

WWPA - COVE/GERMAN/DUTCH LAP SIDING PATTERN 105

(2) CHANNEL RUSTIC LAP SIDING

WWPA - CHANNEL RUSTIC LAP SIDING PATTERN

(3) SHIP LAP SIDING 1/2" LAP

WWPA - SHIP LAP SIDING 1-2 LAP PATTERN

(4) SHIP LAP SIDING 3/8" LAP

WWPA - SHIP LAP SIDING 3-8 LAP PATTERN

(5) SHIP LAP SIDING V2E CENTER V 3/8" LAP

WWPA - SHIP LAP SIDING V2E CENTER V 3-8 LAP PATTERN

(6) SHIP LAP SIDING V2E RUSTIC 3/8" LAP

WWPA - SHIP LAP SIDING V2E RUSTIC 3-8 LAP PATTERN

(7) WWPA - 2x6" QTR LOG SIDING - WITH REVEAL

WWPA - QTR LOG SIDING WITH REVEAL 2x6 PATTERN

(8) WWPA - 2x8" QTR LOG SIDING - WITH REVEAL

WWPA - QTR LOG SIDING WITH REVEAL 2x8 PATTERN

WWPA Bevel Siding Pattern Diagrams

(1) THIN BEVEL SIDING - NO RABBET

WWPA - THIN BEVEL SIDING NO RABBET PATTERN

(2) STANDARD BEVEL SIDING - NO RABBET

WWPA - BEVEL SIDING NO RABBET PATTERN

(3) STANDARD BEVEL SIDING - RABBETED - DOLLY VARDEN

WWPA - BEVEL SIDING RABBETED - DOLLY VARDEN PATTERN

(4) WWPA - THICK BEVEL RABBETED - DOLLY VARDEN

WWPA - THICK BEVEL RABBETED - DOLLY VARDEN PATTERN

WWPA T&G Siding and Paneling Pattern Diagrams

(1) T&G SIDING 106 S2S Drop Edge+Square Edge

WWPA - T&G 106 S2S Drop Edge+SQ Edge PATTERN

(2) T&G SIDING 116 CENTER V S2S Bevel Edge

WWPA - T&G 116 CV S2S Bevel Edge PATTERN

(3) T&G SIDING CENTER MATCH Butt Joint 1/4" Tongue

WWPA - T&G CM Rough Butt Joint 1-4 TNG PATTERN

(4) T&G SIDING CENTER MATCH Butt Joint 3/8" Tongue

WWPA - T&G CM Rough Butt Joint 3-8 TNG PATTERN

(5) T&G SIDING WWPA CENTER MATCH Smooth Butt Joint 1/4" Tongue

WWPA - T&G CM Smooth Butt Joint 1-4 TNG PATTERN

(6) T&G SIDING CENTER MATCH Smooth CM Butt Joint 3/8" Tongue

WWPA - T&G CM Smooth Butt Joint 3-8 TNG PATTERN

(7) T&G PANELING WP-2 Molded Edge+V Edge S2S CENTER MATCH

WWPA - T&G WP-2 Molded Edge+V Edge S2S-CM PATTERN

(8) T&G SIDING WP-4 V2E or V4E

WWPA - T&G WP-4 V2E or V4E PATTERN

(9) T&G PANELING WP-6 Rounded Edge

WWPA - T&G WP-6 Rounded Edge PATTERN

WWPA CEDAR PATTERN BOOK
WWPA Wood Siding Patterns PDF
WWPA Complete Guide PDF

Need to know Guides
Wood Lover's University
A comprehensive education for wood lovers of all types

Homeowners, protect your heart and wallet. Architects, desig...

Wood Siding Installation Tips
Common Sense Wood Siding Seasoning, Storage and Installation Tips for Do It Yourself Homeowner and Builder

It's not rocket science but it has to be done right. Our DIY...

Field or Factory?
When does it make sense to Factory Finish?

A FACTORY FINISH ensures a lasting, higher quality job than ...

Signup to our newsletter

Don't miss out on expert tips & design inspo!

Latest Blogs
We deliver everywhere

National Shipping and Delivery

We carry products from suppliers located all across the country so each delivery will be calculated based on location of customer, location of product manufacturer and weight of total shipment. See Areas we ship to and Delivery Information.

International Shipping and Delivery

Buffalo Lumber offers full 20 and 40 foot container quotes internationally. Europe, Asia, Africa - anywhere a container will go we can get it there. We can only quote full 20 and 40 foot containers - smaller shipments would be customer arranged.

Approved
Buffalo Lumber Company, Inc., Lumber - Retail, Woodbury, TN BUFFALO LUMBER  on HOUZZ

Making mistakes - Fixing something that goes wrong costs 10 times more than it does to do the job right in the first place. Consult with a Buffalo Lumber Milling Expert today.

We can help - Call Buffalo
Top