Does ACQ affect design values? 1

[jopalu]

Does ACQ-treatment of 2x10 & 2x12 lumber, require design value adjustment?

More specifically, after applying the NDS Table 4B Adjustment Factors, Cm for wet service conditions, to SYP #2 & #1 lumber, must design values be further adjusted for ACQ-Treatment?

Thank you ...

 

[SlideRuleEra]

Only if they are incised (Factor Ci) to allow better penetration of the preservative. Otherwise no adjustment in called for when using sawn lumber.

For round poles and piles (not sawn lumber) there is an "Untreated Factor", Cu, that allows an INCREASE in certain properties if the poles/piles are:
1. Air dried
2. Kiln dried
3. Untreated
before treatment.
For the details on this factor for poles & piles see Paragraph 6.3.5 of NDS 2001

http://www.SlideRuleEra.net

 

[jopalu]

SlideRuleEra,

What is "incising"?

Thank you for your reply. Upon furhter research, consulting with an AC-B wood treater, I have been told that Table 4B Factors are the only requirement for the scenario of which I have inquried.

... Off the record - I'm going to miss the "reference from behind and below" graphic so associated with your handle. (as I am not a member of Pats Pub) would it be appropriate to post a vote for "Reference From Behind" vs "Bright Idea"?

Thanks again ...

 

[SlideRuleEra]

Incising is putting a lot of small, longitudinal cuts in the surface of the wood to increase the surface area and allow the preservative to penetrate deeper into the member.
It makes the surface look more like rough lumber than dressed lumber. Paragraph 4.3.8 of NDS 2001 covers these details.

Here is a summary on incising from the American Wood Council (responsible for content of NDS)

http://www.awc.org/HelpOutreach/faq/FAQfiles/Pressure_treat_valu.html

And here is a USDA Forest Products Lab link that discusses it, too.

http://www.fpl.fs.fed.us/documnts/pdf1998/morre98a.pdf

Surely "Reference From Behind vs. Bright Idea" is not that important...

http://www.SlideRuleEra.net