Information for Specifiers of
Treated Wood Products
Engineers and architects, government agencies and
others who develop and maintain project specifications which include
the use of treated wood products have depended on AWPA Standards for
well over 100 years because of its Technical Committees' expertise
in the field of wood protection. Today, specifiers are faced
with many different types of preservatives and species in the
marketplace, so it is
increasingly important for specifiers to continue to specify those
products which meet AWPA Standards.
Why is it important to specify AWPA
A product specified in AWPA has been researched,
evaluated and peer reviewed by the largest body of wood
preservation/protection experts in North America. When a
product has gone through our stringent ANSI accredited process,
we believe they will perform well.
How do I specify treated wood products?
We have developed a simple two-page document which
provides several examples of specifications for treated wood.
Click here to download the document. It is a simple
guide and is not intended to cover all possible uses. After
reviewing the document, if you still have questions or need any
assistance in developing your specifications, please
My specifications call for a number of
AWPA C Standards, but those have been replaced by U1. How
do I update my specifications?
Quite simple, really.
All of the material specifications for treated wood products
listed in all of the C standards are now found in a single AWPA
Standard: U1. The simplest way to update your
specifications is to replace all C standards with U1. If
you wish to have more detail in your specs, such as restricting
the wood to waterborne preservative treatment only, or you wish
to determine the species and Use Category, you may add that as
well. AWPA will be glad to assist you in updating your
specs. Please contact us for any questions you may have.
How may I verify that materials on the
jobsite comply with AWPA Standards?
Products that are compliant with AWPA standards will be
have a clearly legible tag that states it is an AWPA
Standardized product. In order to determine conformance
with AWPA Standards, the end tag will contain the following
AWPA U1 - this shows the
applicable AWPA Standard
AWPA Use Category - examples
are UC2, UC3B, or UC4A which describe the proper application
for the treated wood product
Preservative name and/or code
- examples are Alkaline Copper Quaternary (ACQ-D), Copper
Azole (CA-C), Inorganic Boron (SBX) and many others.
Preservative retention - the
amount of preservative retained in the wood, such as 0.17,
0.21, or 0.40, which varies by the type of preservative used
Inspection agency logo - if
the treating plant subscribes to third-party quality control,
you will see the logo of an agency accredited by the
American Lumber Standard Committee and usually a
"check-mark" logo to make it easier to locate the agency logo.
Manufacturer and Location -
in the event you need a consumer information sheet or
additional information on the product itself, this should help
you locate the treating company
I have references to LP-2 and LP-22.
What do they mean?
"LP-2" and "LP-22" were Inspection Procedures which had been
used by the American Wood Preservers Bureau (AWPB) to determine
the conformance of preservative treated wood products to certain
Standards of the American Wood Protection Association (AWPA).
AWPB ceased to exist on December 31, 1993. "AWPB LP-2" had
often been used as a "shorthand" method of describing lumber and
plywood which had been preservative treated with then-current
waterborne preservatives to a retention of 0.25 pounds per cubic
foot intended for above ground use. In a similar fashion "AWPB
LP-22" had often been used to describe lumber and plywood
treated with waterborne preservatives existing at that time to a
retention of 0.40 pounds per cubic foot intended for soil and
ground contact use. To use current AWPA Standards to
specify the above described material the specifier should call
for AWPA Standard U1. This Standard should be consulted to
determine the species, preservative, and retention level
combination which will provide similar protection to the
Is ACZA, CCA, and Creosote safe for use
in marine environments?
Western Wood Preservers Institute (WWPI) has developed
models on the movement of wood preservatives from piling into
marine environments. They have also sponsored numerous
studies and have developed several publications, including
"Treated Wood in Aquatic Environments Guide" and "Best
Management Practices" for treated wood. WWPI also has
several other informative publications on the
WWPI Aquatics web page. Further
information can be found in a
USDA Forest Service study on preservative leaching in the