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old southern pine density?
2

old southern pine density?

old southern pine density?

(OP)
Anybody know what the DL psf of southern pine from the 1920s was, or the density? I have worn out the phone and google... I have to be as accurate as possible on the weight for a remodel.

3/4" diagonal pine sheathing on a house from the 1920s, in Western North Carolina.

cheers!

RE: old southern pine density?

My 1966 AITC shows 5 psf for 2" nominal Southern Pine. So, using my trusty HP calculator, that yields 1.875 psf DL.

Mike McCann
MMC Engineering

RE: old southern pine density?

(OP)
Sorry, I don't trust HP calculators :D

I actually just found the answer in an old 1899 "Building Trades Pocketbook". 4 psf/inch!

RE: old southern pine density?

Well, my 1958 Douglas-Fir Use Book shows Pine, Longleaf, Southern at 55 pcf unseasoned, and 42 pcf seasoned.

AGAIN, using my very, very trusty HP calculator, that translates to 3.44 and 2.63 psf respectively for 3/4" material. Might check and see if that 4 psf value/in. is a seasoned value or not. Could be a little high.

On considering the long range implications of these calculations, does this mean that old southerners are dense?

Mike McCann
MMC Engineering

RE: old southern pine density?

(OP)
Good thing I'm not old!

RE: old southern pine density?

3.75 psf
HP calculator - 15c used since college in the mid 1980

RE: old southern pine density?

2
SLTA - Per the "1923 Carnegie Pocket Companion", Page 300:

Long Leaf Yellow Pine: 44 Lb/Ft^3
Short Leaf Yellow Pine: 38 Lb/Ft^3

Both were, and are, considered to be "Southern Pine".

If you need printed documentation, you can download the book from this page of my website:
http://www.slideruleera.net/miscellaneous.html

Both the 1917 and 1934 Editions of the Carnegie Pocket Companion also list the same values. So, that pretty well covers the 1920's.

www.SlideRuleEra.net idea
www.VacuumTubeEra.net r2d2

RE: old southern pine density?

The first edition AISC Steel manual provides the exact same densities as quoted by SlideRuleEra. The information is on page 178 in my 1932 (tenth printing) copy.

RE: old southern pine density?

found the answer in an old 1899 "Building Trades Pocketbook". 4 psf/inch!

But, is that calc for today's "skinny" cuts of wood, or for the "original" defintion of 2x4 and 3/4 thick boards or for the roguh cut old-old wood?

RE: old southern pine density?

slta...almost as dense as a contractor

RE: old southern pine density?

Hey Ron... Better qualify that last statemment. A lot of us here do independent contracting.

Mike McCann
MMC Engineering

RE: old southern pine density?

Hey Ron...

Better qualify that last statement. A lot of us here are independent contractors... noevil hammer rofl

Mike McCann
MMC Engineering

RE: old southern pine density?

But then a lot of us here are dense...

RE: old southern pine density?

Very true Hokie... Just like old growth timber. Much better than today's. noevil

Mike McCann
MMC Engineering

RE: old southern pine density?

Mike...Contractor in the sense of those who build things incorrectly that we design!....or more likely, those who build things without bothering to look at the design (as in plans and specs).

hokie66....I'm a lot more dense than Southern Pine. I'd be classified as hardwood....and not necessarily in a good way.

RE: old southern pine density?

@SLTA;

Just curious on how you would have to be that accurate where +/-1 PSF of DL on the floors or walls would make that much difference?

RE: old southern pine density?

ExcelEngineering.....simply to answer the question that the attempt was made to be as accurate in all aspects of the evaluation as practicable. It's called "liability"!

RE: old southern pine density?

(OP)
In this case, the size of what I'm supporting above would mean the difference between steel or engineered lumber, if I'm too heavy, and unacceptable deflections if I'm too light. Plus what Ron said.

RE: old southern pine density?

I get what you are saying, but in the grand scheme of things, minor differences in the weight of sheathing should not be the deciding factor in what type of beam you should use - unless the only thing you are carrying IS sheathing or if you are designing to the gnat's ass - something that is a waste of time in wood construction, IMHO.

RE: old southern pine density?

(OP)
Excel, trust me that in this case, for this project, it matters.

RE: old southern pine density?

That is why I was asking. I was curious why it mattered so much.

RE: old southern pine density?

Excel, I was thinking the same thing. In new design, you can just throw 10psf weight of materials at the design and run with it. But maybe it is a historic building or renovation and he can just barely make it pass code. But then someone better tell them to never exceed 50psf LL (or whatever LL is) thumbsup2

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