Latest News

Treated Wood Guide app updated, improved

Guided by comments and input from users over the past year, the treated wood industry’s exclusive smartphone app has undergone a complete makeover.

Version 2.0 of the Treated Wood Guide smartphone app is available for free downloading for iPhones, Google and Windows smartphones in their respective app stores.

The app features a redsigned section on AWPA treating standards, tips for working with preserved wood and a new Treated Lumber Yards Nearby utility to find retailers stocking preserved wood products (see the online version here.) Retailers interested in getting a listing for their company can review the materials in the Treated Lumberyards Nearby section.

Simpson Strong-Tie alters corrosion warnings

Testing done by Simpson Strong-Tie has led the fastner maker to change its recommendations for steel connectors and fastners used with wood treated with preservatives containing ammonia.

Earlier this year, Simpson issued a letter announcing its in-house testing "concluded that there is no significant difference in corrosion activity in galvanized steel in contact with treatments with or without ammonia." As a result, it has changed its recommendations in favor of using hot-dipped galvanized and stainless steel connectors and fastners for preservatives such as ACQ and ACZA. Previously, it recommended only stainless steel for use with those preservatives.

Simpson is now revising its online materials to reflect the new recommendations.


About Western Wood Preservers Institute - WWPI

Headquartered in Vancouver, Washington, the Western Wood Preservers Institute (WWPI) is a nonprofit member trade organization representing the interest of the preserved wood products industry throughout western North America for more than 60 years. The membership consists of companies that either manufacture products, are directly affiliated or provide a service to the preserved wood industry. The primary activity areas of the WWPI include regulatory and market outreach programs aimed at sustaining a viable western North America preserved wood industry.

WWPI Purpose Statement

To support and sustain the production and use of treated wood products manufactured in western North America.

WWPI Mission Statement

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It is the WWPI mission to protect and promote the manufacture and markets for preservative treated wood products produced by the industry in western North America. This shall be accomplished through coordinated industry strategies, utilizing the best scientific information available to:
  • Increase public and consumer appreciation and confidence in our products and our industry;
  • Secure reasonable and economic federal, state, provincial and local environmental regulation regarding our products and processes;
  • Promote the development and application of codes, standards and Quality Assurance programs to ensure products best meet the needs of the users.

WWPI Environmental Code

Members of WWPI share the public concerns for a sound economy, healthy environment and good stewardship of all natural resources.
To that end, the members strive to achieve the following principals:
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  • To produce high quality products which, when used as intended, will significantly extend the useful life of the treated wood material.
  • To operate facilities in a manner which meets or exceeds applicable federal, state or provincial regulations.
  • To support and utilize research aimed at developing products and processes which are consumer and environmentally friendly.
  • To participate in the development of public regulations and product standards which are based on sound scientific information and balance the long term need for a strong economy and healthy environment.
  • To actively support the reuse and recycling of treated wood products.


The Western Wood Preservers Institute believes the information contained on this Web Site to be based on up-to-date scientific and economic information and is intended for general informational purposes. In furnishing this information, the Institute make no warranty or representation, either expressed or implied, as to the reliability or accuracy of such information; nor does the Institute assume any liability resulting from use of or reliance upon the information by any party. This document should also not be construed as a specific endorsement or warranty, direct or implied, of treated wood products or preservatives, in terms of performance, environmental impact, or safety. The information contained herein should not be construed as a recommendation to violate any federal, provincial, state or municipal law, rule or regulation, and any party using or producing pressure treated wood products should review all such laws, rules or regulations prior to using or producing treated wood products.

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