board feet and quarters

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A board foot is defined as a 1' x 1' x 1" or combinations to get 144 cu inch of material. When I go to the lumber store a 1" thick board is actually 3/4".
When I see lumber listed as 4/4, 5/4, 6/4, 8/4, etc, what should I actually be able measue it out as?
If I have wood that measures as 2" thick with my tapemeasure, how would I express that in quarters?
This likely has come up before, but I just got into discussion with a 50%er engineer who just absolutely "knows" because the degree in his pocket says so.
Pete
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Expressed as: Your tape measure is worth 8 quarters (or $2.00). Comparable to a $2 watch.
From your lumber yard, you will likely not find finished lumber that measures a full 2", but slightly less than exactly 2". This finished lumber measure would be expressed as 8/4, as the original rough cut stock, it came from, was originally a full 2" measure. Only rough cut lumber will be a full 2" measure, unless it is a special cut of particular lumber.
You won't find $2 watches at the lumber yard, either. .... I don't think! ..... maybe?
Sonny
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Sonny, tell your idiot engineer to stick to his line of expertise.
There is a ton of information on this phenomenon that started as soon as sawmills began to sell planed wood. So maybe a couple of hundred years ago....
To overly simplify, a board foot is the size of the board BEFORE it was planed or smoothed. So a 1X6 was a board that began as 1" thick, and 6" wide. However, to make it convenient, you began to be able to buy planed boards from the mill. Planing decreased the thickness on each side and the edges, so the sizes you see now reflect the fact that the wood has been processed to a consistent size, or its finished size.
However, the mill still cut it 1"X6" so they would have enough material on the board to smooth it. You didn't think you would get that extra material free, right? So you are charged for the board itself when rough, as well as the convenience of smoothed faces. To drive that home, go to a real hardwood lumber store (NOT HD) and ask for a 1X6. They should ask you "nominal (unplaned) or smooth?". If rough, you can take the board home and plane it yourself. Make to your own smooth boards to your dimensions using nominally sized lumber.
As far as quarters go... think about it. Maybe since it's Thanksgiving, think of an pie as an inch to visualize it. With that in mind, think of one quarter of a pie as "a quarter of a pie". So to extrapolate, if you have one quarter of an inch, then you have..... wait for it..... here it comes..... one quarter of an inch!
So 4 quarters would be..... one inch! Five quarters would be..... an inch and a quarter. Eight quarters would be two inches, etc. Just count the quarters on your tape and you will have it.
IME, the quarter system of describing wood sizes is used only to describe thickness of rough (nominal) lumber. It is not used to determine width. You won't find an lumber man that asks you if you want 4/4 (four quarters) by 24/4 (24 quarters) by 400/4.
You should also know that unless it is in a specific purpose lumber, nominal sizes almost always refer to hardwoods, not softwoods.
Some engineers are pretty bright fellows, but this one sounds brand new. Show him this to help educate him as to how BF is calculated, and after that DAGS the key words.
http://preview.tinyurl.com/c7nlgl
Check out the highlighted words in this book, page 216. "Understanding Wood" (to me) is the absolutely undisputed king of reference books on all things wood.
http://preview.tinyurl.com/2fs4d32
Robert
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Whoops....
Sorry, Sonny. Meant Pete. Lost my train of thought when I went for more coffee!
Robert
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Every industry has its catchwords, slang and standards that may not make sense to someone who in not initiated into the way things are done. I came out the printing industry, and most people cannot figure out paper weights. Can any one reading this tell me how 20 pound copy paper is determined, versus 24 pound copy paper?
Like lumber where sizes are determined in the rough unfinished state, paper is determined in the mill sizes that the paper mill standardizes. Copy paper, known as Bond paper because it is used for business letterhead and forms, and now used for copiers is based on a ream, which is 500 sheets, of standard sized paper. Bond paper is produced in the standard size of 17" x 22", and 500 sheets will weight 20 pounds or 24 pounds respectively. Other sizes are produced but the weight is based on the standard size.
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But, if you're talking about Coated or Cover or paper of a type other than Bond, the "standard" size isn't standard at all. I couldn't tell what the engineer in the OP was claiming, so don't see any basis for calling him an idiot. Kerry
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On Wed, 24 Nov 2010 18:15:50 -0800, "Kerry Montgomery"

Yup - weight of a standard quantity of paper

You asked us, then gave us the answer - no fair!!!!!

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Actually, there -is- a 'standard' size for every type of paper -- the so- called "basis size" for that type of stock. The size is just different, depending on the type of stock. involved.
The 'full sheet' sizes for the various types of paper are 'de facto' standardized across manufacturers, simply because they have to be fed to the same presses. <grin>
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*I* can. But, then, my folks bought a _lot_ of printing, and lots of different kinds of paper stock, as part of their business operations. I also know the difference between letterpress and offset printing. And have used an honest- to-goodness Lin-o-type machine. 0<grin>
I've also written computer software to calculate postage costs for mailings, given only 'how many pieces' of 'what kind of paper' went into the envelope. {This program had enough 'smarts' in it that it would tell you if eliminating _one_ (or sometimes two) sheets from the run would save on postage. Over time, made for about a 10% reduction in postage costs for the mailings.}
One of the _few_ times my print-shop *didn't* have an 'instant answer' for me was the day I called up and asked "the paper stock we use, what's the _basis_size_ for it?" He'd _never_ had a customer ask *that* question before. <grin>
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snipped-for-privacy@aol.com wrote:

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wrote:

This online tool ( http://preview.tinyurl.com/c7nlgl ) is very useful, thanks
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Bookmarked... thank you.
--

-MIKE-

"Playing is not something I do at night, it's my function in life"
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snipped-for-privacy@mts.net wrote:

Because it has been surfaced. Rough, it was 4/4; surfacing removes up to 1/4".

At *least* what it says; i.e., 4/4 should be 1" minimum. In practice, they are often greater than stated by 1/8"-1/4".

8/4
--

dadiOH
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snipped-for-privacy@mts.net wrote:

B) first... :) 8/4, of course. (+)
A) Depends on what lumber of which you speak. Rough-sawn, it'll be full dimension. What it will clean up to will depend somewhat on the sawyer and saw type as well as the particular board -- a bandsawn piece w/ a careful sawyer may need 1/16" or even less to leave a clean surface whereas a circular saw and/or a little less care taken might need as much as an eight or slightly more on occasion.
If you're talking about softwood dimension lumber (tubafor and the like), the sizes have been standardized at the half-under thickness for uniformity. Used to be you would find finished 2x at 5/8 or thereabouts and not necessarily identical so matching up thickness was a trick.
There are grading and sizing rules; I thought I had a handy link but don't seem to find it at the moment. US Forest Products Lab site should be able to find it but I'm in a rush at the moment, sorry...
(+) Of course, if that were finished piece, it was originally probably 10/4 (9/4 would be theoretically possible but rarely is anything sawn at that thickness unless were custom order).
--
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snipped-for-privacy@mts.net wrote:

When you see lumber listed in quarters, that's in the rough. 5/4 will usually give you 1 1/8 usable lumber and so on. 2" is 8/4 before surfacing hth
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If it's rough then divide out the fraction and the lumber should be not less than that thickness in inches.
If it's sold surfaced ("S2S", "S3S", or "S4S") then it should be 3/16 less than the rough thickness if the rough thickness is 6/4 or less, or 1/4 inch less if it's thicker than 6/4.
If you're buying it at the yard and they store it rough they may be able to plane it so that it's thicker than that for you depending on the actual thickness of the stock they have and the actual degree of roughness, but it's not something to count on.
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12/4 = 3" 8/4 = 2" 4/4 = 1"
The store bought stuff usually is listed as a nominal sizes. IE: a 2 x 4 x 10 was 2" x 4, but has been planned / dried a bit to 1 1/2" x 3 1/2"
On 11/24/2010 12:10 PM, snipped-for-privacy@mts.net wrote:

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In defense of my fellow Eng-gun-near, you have to define the problem.
Do you want to talk about lumber in the primary "as cut" mode straight from the sawmill or do you want to talk about lumber that has had secondary machining performed on it to provide finished dimensional lumber?
Rough cut lumber is described using the "quarter" method, thus 4/4 1", 8/4 = 2", etc.
Dimensional lumber uses the nominal size to describe it's size; however, it's actual size is less since it includes a machining allowance.
Thus a "1x6" actually measures 3/4" x 5-1/2" these days.
The actual sizes are published.
BTW, when buying rough lumber, you measure a board at it's widest point to calculate board feet.
Thus a 4/4 board that is 8 ft long and varies from 9" wide at one end to 12" wide at the other is considered to be an 8 board foot board. (It is assumed to be 12" for the full length for BF calculation purposes.)
It's a little gotcha that gets passed on.
Lew
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On 11/24/2010 6:14 PM, Lew Hodgett wrote:

Not at the hardwood supply place where I do business (Fine Lumber here in Austin TX). If there is any significant variance in width they will take several measurements and compute the average width and charge accordingly.
It's a little gesture of good will that keeps me coming back.
--
See Nad. See Nad go. Go Nad!
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On 11/24/10 7:15 PM, Steve Turner wrote:

Must be nice. My place doesn't have such good will, and it keeps me looking for a new place.
--

-MIKE-

"Playing is not something I do at night, it's my function in life"
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