New AWPA-U1 wood treatments replace C2

Archive of Older Topics Archive - Specifications Discussions #3
1

Has anyone else started to spec with AWPA-U1 for preservative treated lumber? I don’t know if contractors will be able to find lumber with the new designations or not, but the new standard has been out for a good while now.

http://www.awpa.com/standards/organization.asp
http://www.awpa.com/standards/ucs.asp
http://www.awpa.com/standards/U1-07_Excerpt.pdf

I’ve been spec’ing U1 for a year or 2 now, and have not heard any complaints, but I finally got curious enough to call a preservative treater myself and they did not seem to be very familiar with U1 (or the old C2 for that matter), though they said they are adamant about only using AWPA approved treatments at least. It’s only been 4 years now since the AWPA made the switch, c’mon now!

My spec looks something like this:

2.2 WOOD-PRESERVATIVE-TREATED MATERIALS
A. Preservative Treatment by Pressure Process: AWPA U1.
1. Preservative Chemicals: Acceptable to authorities having jurisdiction and containing no arsenic or chromium.
Edit examples in lists below, or delete the following and subparagraphs.
2. Use Categories:
a. AWPA U1-UC1: Interior, dry applications, such as [blocking in interior partitions] [, millwork].
b. AWPA U1-UC2: Interior, potentially damp applications, such as [blocking in exterior walls] [, sill plates].
c. AWPA U1-UC3A: Exterior, coated not in contact with ground, such as [cants], coated millwork, siding, trim.
d. AWPA U1-UC3B: Exterior, non-coated not in contact with ground, such as [decking, sills, walkways, piers, railings/pickets].
Normally delete the remaining use categories below except for special project requirements
e. [AWPA U1-UC4A: Exterior, in contact with ground normal, such as fence/deck posts.]
f. [AWPA U1-UC4B: Exterior in contact with ground severe environment/critically important, such as utility/building poles, salt water splash zones]
g. [AWPA U1-UC4C: Exterior very severe, such as piling, utility poles in semi-tropical or tropical areas]
h. [AWPA U1-UC5B: Exposed to salt water between NJ and Georgia/south of San Francisco]

2

I was not even aware of this change. We just recently purchased from ICC the AWPA standards “as referenced in the 2003/2006 IBC and IRC” since the AWPA standards book cost 250 bucks. None of the U1 designations are listed in the book we bought, so I guess the IBC is not current in that respect. (Plus I feel snookered for not getting the most current standards.) It’s interesting that the 2006 IBC uses the C standards, even though AWPA eliminated them in 2003. Thanks for the tip, and I’ll have to look into this further.

3

I have similar concerns. One of my next projects is to migrate our specifications to the new system.

I would assume that when placing these provisions in the Rough Caprentry section that you would delete provisions dealing with siding and trim.

How does the contractor know whether he is in a semi-tropical or tropical area?

4

Thanks Christopher. I see MasterSpec still uses the C numbering. I appreciate your list of what the new designations should be. I’m updating our masters now.

5

Mark, I would probably select the specific use category when specifying. That way the Contractor doesn’t have to know whether it is semi-tropical or tropical, though we would.

6

AWPA updated treatment specifications four years ago, but there was a transition; C specs were deleted in '05. IBC 2006 includes U specs. Master spec is dated '05 but has an '07 update, yet still includes the C specs.

Industry problem of coordinating Standards: Codes: and commercial masters. then the distribution throughout the industry.

Thanks for the info.

7

Wow, a great response to such an insipid question!

Yes, when preparing a project spec I delete the use categories and any material examples that do not apply. The titles of the use categories, like …like tropical/semi-tropical…, are just pulled from the standard (A word of caution, the '05 version is the most recent one I had studied when writing this, I don’t know if any might have changed.)

Will see what Arcom thinks about reviewing and considering for a future update.

Thanks all!