Wood Roof Joist Grade 1

[SperlingPE]

I am looking at an existing roof framing plan. The joists are called out as 2x12's or 2x14's at various spacings. The grade of the joists are called out as 123-b and 123-c. Does anyone know what this is referring to?

 

[JAE]

Sperling - never heard of it. It isn't a mechanically graded term. Is there some sort of schedule on the plans that it refers to? the b and c seem to reflect that possibility.

 

[woodengineer]

"[ WCLIB]. Use. Grade. Grading Rule. Stress F. b. Rafter, joist, studding 2 x 6 and. [ No. 1]. [ Para. 123-b]."

-According to my google search it would appear that 123-b and 123-c are paragraphs within the WCLIB (West Coast Lumber Inspection Bureau) grading standards.

Your question peaked my interest, I had never heard of lumber being designated in this way.

Good Luck!

woodengineer

 

[woodengineer]

Apparently, Para 123-b of WCLIB refers to grading requirements for structures (rather than sign posts, fences,etc.), specifically, No. 1 and better, grade for materials 2" to 4" nominal thick, 5" nominal and wider (Structural joists and planks)

woodengineer

 

[SperlingPE]

Woodengineer

Does the paragraph site any engineering values (Fb, Fv, E, etc.)?

 

[woodengineer]

SperlingPE,

I could not find any design values from my cursory search. It did specify #1 or better though.

Go to the WLCIB website and they have a link and a contact number to that associations board. I start with a phone call to that agency.

Sorry I couldn't be more help. Good luck.

woodengineer

 

[RARWOOD]

The specification is incorrectly associating the grade with the location of that grade in the WCLIB grade rule book. The correct grades are No. 1 & No. 2 Structural Joists and Planks.

If they had used the WWPA grade rule book, and called the grades out as 62.11 & 62.12 they would hace made the same mistake.

In the US & Canada lumber graded for structural use, that is 2" to 4" thick and 2" wide and wider, is grade according to the National Grade Rule. That means that the grade rules for No. 1 Structural Joists & Planks are the same in the WWPA, WCLIB, NLGA, & SPIB grade rule books. However they have different section numbers in the different rule books.

To find the design values look in the NDS supplement for N0. 1 & No. 2 grades.

A good example of the uniform grading is SPF(South), the NDS values applies to lumber graded by NELMA, NSLB, WCLIB or WWPA. It applies to lumber graded by any of these agencies because the grade rules are the same. In some cases there is only one Grading Rules Agency listed for a species because that is the only Agency that grades wood of that species. For exapmle NLGA is listed for SPF, because SPF is only produced in Canada so the Grading Agency is the National Lumber Authority of Canada.

 

[SperlingPE]

Next wrinkle to this puzzle is that the buildig was built in the mid-1950's. Any idea as to what some engineering values would have been?
Fb? E? Fv? etc.

 

[jheidt2543]

SperlingPE

Sorry this is so late, but have you tried the U.S. Forest Products Lab in Madision, WI? They have an extensive library on the engineering properties of wood and may have those values.