Equivalent wood grades

Yes, the grading agencies modify the allowable stresses frequently (every code cycle if it's southern pine). It wouldn't surprise me if the grades have also changed over time. You will probably need to locate what the allowable stresses are for each of the different grades and compare them to modern grades. I imagine its probably pretty analagous to Select Structural, #1, #2, and Stud.

My 1931 Kidder Parker has for coastal DF:

Dense Super-Structural
Super-structural and dense structural
Structural
Common Structural

I tried to post a picture but the attached will have to suffice. This old book is fantastic if you can afford it. It's not too bad.

Does this help?

njlutzwe,

Just out of curiosity, do they give the allowable stresses in your book?

Sorry I didn't attached right. Check out this and let me know if it helps.

I'm specifically looking for bending and shear stress capacities for a 1973 project, for DF No 2. The UBC archives are not freely available and quite costly (up to $200 a copy). Any way I can get these values? I feel like this stuff should be public information...

awa5114...keep in mind that the ICC is a profit seeking organization. I agree it should be public information; however, even in my state where the building code is a statutory document, we still have to buy it!

Awa5114:
Take a look at the NDS (National Design Spec. for Wood Construction, or NDS for Stress-Graded Lumber and Its Fasteners) and its various Supplements (various supplement years) for the specific wood grades and design stresses. That’s what would most likely have been followed for the design of a wood structure at that time. Not only do you have to pay attention to the species, but also to the grade name and then the specific grading agency in some cases. See if you can find some grading stamps on the members, for starters. Then, what NDS and its supplements was being used at that time, in your area? The UBC essentially copied the NDS, literally word for word, at that time. In fact, copies of the UBC from that time contained the complete AISC, ACI and NDS codes, and others, within its covers and it could be carried in one hand. 5.5"x8.25" high by 1.75" thick; it was reasonably affordable, usable and understandable too. Ah... for the good old days. The allowable stresses and the mech. properties have continued to decline in value, over the years, as we’ve learned some new things about wood, and as we are cutting younger and younger trees for lumber, wood quality has deteriorated.

Ron,
I am somewhat hesitant to post this link to old UBCs. But, I am assuming UC Berkley's Library respects all copyrights. Perhaps, they have permission, or the copyrights have lapsed.
1927-1961: 1967-1994:
If anyone thinks it violates any intellectual property rights, please red flag this post!

Wannabe,

I think, and don't quote me, but I think the old codes may be available via FOIA. Codes were law at one time. We have a right to know what the law is. If someone knows this for sure, please comment.

Btw, FOIA is freedom of info act for those of you in Rio Linda

ICC said:

Welcome to the International Code Council Online Library​

Welcome to the eCodes Free Subscription Web Site. This site is designed to allow you to view the International Codes, State-Adopted Codes, and various Archived Codes for free. Please check with your local jurisdiction for the most up-to-date code edition year and adoption date. You are limited in your abilities to search and print, however all sections of the codes are available for you.

Click to expand...

There is public e-codes here: Link

Not sure if it has what the OP desires.

My 1973 UBC shows 1250 psi and 1450 psi for single and rep uses for DF#2, 2" to 4" thick, 6" and wider.

Unfortunately, I do not have anything earlier.

Mike McCann, PE, SE (WA)

awa, try the below. This is from a 1958 DF Use Book.

Amazing! My copy shows the same thing!

Mike McCann, PE, SE (WA)