Identifying Existing Wood Member 1

[SteelPE]

I have been asked to do some major renovations to an existing building. The building has a wood framed floor on steel beam girders (above a basement) and a wood trussed roof.

During my inspection of the floor I did my best to note the marks on the side of the floor joists which are as follows:

Joist #1
2.5” x11.25”, DFIR, STAND, PLIB, WCLB

Joist #2
1.5” x 11.25”, WCH, STAND, WCLB RULES.

Joist #1 is obvious it is a standard grade 3x12 Douglas Fir floor joists. I never knew they made standard grade as I have never used it before. This is not a good grade of wood.

Joist #2 appears to be a standard grade 2x12 joists but what species would it be? I couldn’t find any other marks on the wood joist.

The building is pretty old but not that old (if it means anything). Does anyone have any insight as to what type of lumber this may be?

 

[SlideRuleEra]

Contact

http://www.wclib.org/

For reference, the lumber in the building was produced in 1964, or later. The 1.5" thickness (reduced from 1 5/8") was adopted then. See "History of Yard Lumber Sizes" on this page of my website:

http://www.slideruleera.net/USDA-FPL.html

http://www.SlideRuleEra.net

http://www.VacuumTubeEra.net

 

[Ron]

The "WCH" possibly stands for Western Cedar Heartwood. Will have a lower E than most other species.

 

[SteelPE]

Let me ask a follow up question.

Have the values for bending strength for standard grade lumbers stayed relatively the same over the years?

I’ve only dabbled in wood design here and there. The only version of the NDS I have is 1997. The Fb values I have for the Douglas Fir and Western Cedar members are 575 psi and 450 psi respectively.

 

[KBVT]

I believe the Fb values have been relatively consistent, the Fv values however were increased since your 1997 NDS.

 

[SteelPE]

I’m more concerned with past years. Has the lumber grades always been select structural, #1, #2, #3, stud, standard and utility with similar Fb values?

 

[SteelPE]

Alright,

Back out onsite this afternoon to find that the wood grade is a mix of both construction and standard grades randomly mixed (now I have photos of the markings on the side of the wood members).

I don’t quite know how I will rate the floor now? Most of the wood appears to be Construction Grade.

Oh, and I believe the building is pre 1971

 

[SteelPE]

and some more photos

 

[OldPaperMaker]

SteelPE,
I suggest that you fire up Google and type in "WCLB". They are still very much in business with phone numbers, e-mail. etc. and can give you chapter and verse about what grade, specie and mill that produced the lumber. Once you have the grade & specie you can use the allowable stresses in the current NDS to evaluate the structure.

If you don't have the current NDS you can access the data at the American Forest & Paper Association's web site which is

http://www.awc.org

Don't forget the Adjustment Factors like Repetitive Member, Cr, Size Factor, C (subF) and Duration Factor, C (sub D) for snow, etc. can be applied to the values found in the NDS.

You don't mention what area of the country you are located in but in the Pacific NW it would be very unusual to have a floor or roof system constructed from western cedar 2x12's unless this is an outdoor deck. Also, I don't think that any mills in the NW have manufactured a 3x12 except for a special order.

I hope that this helps.

 

[SteelPE]

I do plan on contacting the WCLB. I am just trying to get all of “my ducks in a row” for when I call. I figured it would be easier to send them pictures of the markings on the side of the members rather than try and describe it to them (in case I forgot something).

 

[Ron]

SteelPE...if the remainder of the wood looks like the photos, those appear to be undergraded...pretty nice wood...consistent, parallel grain, few knots, etc.

 

[SteelPE]

And the answer is.... West Coast Hemlock.

However, the lumber grading on the side of the memeber does not relate to the grading used today (fyi).

 

[OldPaperMaker]

SteelPE,
West Coast Hemlock has been graded as Hem-Fir for the last 30 years.

The NDS gives the following design values for Standard grade, 2" -4" wide, Hem-Fir (to use with Adjustment Factors):
Fb=550 psi, Ft=325psi, Fv=150psi, Fc=1300psi & E=1,400,000 psi

 

[SteelPE]

OldPaperMaker

In talking to the WCLIB, they stated that they use different grading rules back then than they use today and they don’t really relate to each other. He said that a construction grade would be similar to a #2 today however a standard grade could be a #3 or a #2 in today’s standards (a #3 would be punishing to my existing floor which is not changing occupancy).

The gentleman from the WCLIB was nice enough to give me the original standards used to grade the lumber together with the standards used today for comparison. He said there are companies that will come out onsite to grade the lumber…. We are currently checking that out as well as looking at other options.

Thanks for your help

 

[Ron]

SteelPE...thanks for the follow-up info. That's always good to have the loops closed in these threads. I thought the lumber looked better than its grading, so good to know that rules and terminology have changed.