I recently ran into an issue that I thought was important to write about.  

We had a someone call us (Buttolph Lumber) about getting pressure treated lumber. We were also given the specs that the architect was authorizing for the job.

The specs said: 

1. Preservative Treatment Standard: American Wood Preservers’ Association (AWPA) “C2″

2. Preservative Material: ACQ, alkaline copper quaternary

In addition, we got back remarks from the architect asking for “additional documentation indicating compliance with AWPA C31, AWPA C20 and/or AWPA C27.”

So… what is the big deal?  We see this type of spec all the time.  There are a couple of issues here; some specific to the job, others specific to the industry.

1. For this job we are only able to find material using the Osmose Lifewood product (you will have to trust me on this).  This is the new Micronized pressure treatment that is being used by many treaters.

a. The issue is that Osmose will not let the AWPA (now American Wood Protection Association) certify their material to their standards because they are unwilling to “pull back the curtain” on their proprietary process.

b. But… this doesn’t mean that Osmose has not been certified that their product works.  They use a different agency that allows them (I have to assume) to keep their proprietary technology secret.  Lifewood is covered under the ICC ESR 2840 report from  ICC Evaluation Service.

c. The biggest problem comes from the fact that most architects use the AWPA Standards Book as their bible when writing their spec documents and now, the hottest new product out there (or at least it seems that way when a lot of the big treaters are moving to it) isn’t in that book.  There may be an issue with trying to convince an architect that they have to use a standards system (ICC-ES) that they may not be familiar with as the basis for writing their pressure treatment specs.

2. The second issue with the spec as it is written is that it uses the “C” codes as a reference.  The AWPA no longer recognizes these codes in their standard (they have been recently deleted).  So, if you have an architect (or are an architect) specifying these codes in their documentation follow this link to buy the new AWPA Standards Book or visit the AWPA web site to learn more about their publications.

a. The AWPA now recognizes Use Categories (UC) in their standard.  This is what the AWPA states as the purpose of use categories:

“The Use Category System provides a simple way of using the AWPA Standards.  The system was introduced in 1999 and defines Use Categories, or biodeterioration hazard levels, for treated wood products.  The UCS assists specifiers and users in the selection of the appropriate treatment for the end use of the product.

The advantage of the UCS is simplicity.  All treated wood products can be placed into one of five use categories, based upon biodeterioration hazard and expected product performance.  Fire retardant treated products are placed in their own unique use category class.”

b. The Use Categories that Lifewood is certified for are:

UC1 - Interior construction, above ground, dry

UC2 - Interior construction, above ground, damp

UC3A - Exterior construction, above ground, coated (I think this means painted) and rapid water runoff

UC3B - Exterior construction, above ground, uncoated and poor water runoff

UC4A - Ground contact - general use

UC4B - Ground contract - critical structural 

c. The Use Categories that Lifewood is NOT certified for are:

UC4C - Exterior, ground or freshwater contact, very severe conditions, or very critcal structural components

UC5A - Saltwater exposure - north of San Francisco and New Jersey

UC5B - Saltwater exposure - south of San Francisco on West Coast, New Jersey through Georgia on Ease Coast

UC5C - Salwater exposure - south of Georgia, Gulf Coast

UCFA - Fire protection, weather-shielded

UCFB - Fire protection, exterior

d. As a note: Even though the Osmose company doesn’t use the AWPA for their standards the ICC-ES does reference and certify the Lifewood material to the different Use Categories that the AWPA has set forth. 

 

This entry was posted on Tuesday, May 12th, 2009 at 11:05 am and is filed under Pressure Treatment. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.