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Wood thickness
By:Paul G. Jacobson
Date: 10/27/2007, 1:27 pm
In Response To: Re: Strip: Cedar thickness (Bill Hamm)

: Well actually in the better lumber yards in the states you pay the same way,
: by the board foot ie: 12" wide by 12" long by 1" thick. If
: the wood is a smaller dimmension you just do the math and pay for what you
: get.

: Bill H.

That would be a nominal measure, though. They figure the wood at the rough-cut size, but what you get is "finished" size. What you lost in the "finishing" is sawdust somewhere, but you are paying for it. With softwoods you lose the most, and sizes are more standardized with construction and softwood lumber. While there are industry standards for hardwoods, all too often a hardwood dealer will sell something that is slightly off spec., particularly if they mill it themselves.

Cedar is sometimes considered a construction material and cut to common softwood sizing specifications. But some lumberyards consider it a hardwood, and the size of the boards will vary. Clear cedar, being an item that is used more like a hardwood (for finished products) as opposed to common cedar boards, such as those used for decks and siding, may be sized, and priced more like hardwoods. At the same time you'll probably encounter oak, maple, and poplar (all hardwoods) being sized the same as pine, spruce, and fir. You'll see this most often at the big-box homecenters.

For example, nominal 2-inch boards (softwood) are finished to an actual 1 1/2 inches, and nominal 1-inch boards (softwood) are finished to 3/4 inch. With hardwoods you get a thicker piece, and it will vary.

The width of the boards can vary as well. With softwoods a nominal 12-inch-wide board is going to be 11 1/4 wide. You seem to lose 3/4 of an inch here.

But a nominal 6 inch width is 5 1/2 inches, so if you rip that 12 inch board in half, allowing for 1/8th inch kerf, your home-ripped boards are going to each be 1/16th wider than boards you would buy at the store.

So when you get common softwood lumber a board foot of 1 x 12 would actually measure 1 foot long by 11.25 wide by .75 thick. If you were to by nominal 1x2's, the loss would be greater. these only measure 1 1/2 inches wide. Six of these, side by side would only measure 9 inches, but that's what you woudl get in a board foot of 1x2s--a piece .75 thick, 12 inches long, and equivalent to 9 inches wide.

Should you decide you need 1x2s and figure on ripping your own from a 1x12, with 5 rip cuts taking out 5/8ths inch of material, you'll be splitting the remaining 10 5/8-wide board into 6 pieces which are a bit over 1 3/4 inches wide. But why do that when with 6 rip cuts, removing 3/4 inch of stock in those 1/8th inch kerfs, you can actually rip the remaining 10.5 of good wood into seven, not six 1x2s.

Yes this is confusing--just like the odds at a casino--and the lumberyards are usually the winners. There are some exceptions. I've run into some places where the employees weren't sure how the management set the prices, or the management had their own rules on figuring boardfeet. They would look at the listed price per board foot, and if the wood measured 3/4 inch thick they would charge you 75 percent of the listed rate. Sometimes they would figure the actual width of a board, as well.

The moral here is to ask how rates are calculated at that particular lumberyard before buying, or comparing their price with the competition.

Caveat Emptor (let the buyer beware)

In April 2003 The United States Department of Agriculture (USDA) published a study on this (http://www.treesearch.fs.fed.us/pubs/22353) and found that after observing data from 14 different mills, starting in 1996:
"The width of the dry, 4/4 thickness, red oak lumber sample was significantly influenced by lumber grade, lumber length, and mill. The dominant lumber widthclass was 5.00 to 6.75 inches (47 % of all boards). Boards in the FAS and FAS-1F grades were wider than those in the No. 1, No. 2A, and No. 3A Common grades, and these were wider than the Selects grade boards. There was significant variability in lumber size attributes between mills, supporting the contention that each mill must collect its own data on lumber size and quality characteristics for optimal decision making"

The enire report is available here: http://www.fs.fed.us/ne/newtown_square/publications/other_publishers/OCR/ne_2003_wiedenbeck002.pdf

Hope this helps

PGJ

Messages In This Thread

Strip: Cedar thickness
Tim -- 10/24/2007, 8:56 am
history of wood thickness *LINK*
Paul G. Jacobson -- 10/27/2007, 3:25 pm
Re: history of wood thickness
Bill Hamm -- 10/28/2007, 1:46 am
Re: history of wood thickness
Paul G. Jacobson -- 10/28/2007, 7:56 am
Re: history of wood thickness
Mike Savage -- 10/28/2007, 11:14 am
Re: Strip: Cedar thickness
Bill Hamm -- 10/25/2007, 12:36 am
Re: Strip: Cedar thickness
Acors -- 10/25/2007, 9:07 am
Re: Strip: Cedar thickness
Bill Hamm -- 10/26/2007, 1:25 am
Wood thickness
Paul G. Jacobson -- 10/27/2007, 1:27 pm
wood thickness pt 2
Paul G. Jacobson -- 10/27/2007, 1:34 pm
Re: wood thickness pt 2
Bill Hamm -- 10/28/2007, 1:43 am
Wood thickness Pt 1
Paul G. Jacobson -- 10/27/2007, 1:31 pm
Re: Strip: Cedar thickness
TOM RAYMOND -- 10/27/2007, 12:41 pm
Re: Strip: Cedar thickness
Bill Hamm -- 10/28/2007, 1:39 am
Re: Strip: Cedar thickness
Kurt Maurer -- 10/24/2007, 6:58 pm
Re: Strip: Cedar thickness
Ken Blanton -- 10/24/2007, 6:00 pm
Strip: Cedar thickness
Jay Babina -- 10/24/2007, 2:19 pm
Re: Strip: Cedar thickness
Acors -- 10/24/2007, 1:20 pm
Re: Strip: Cedar thickness
Mike Scarborough -- 10/24/2007, 9:01 am
Re: Strip: Cedar thickness
Glen Smith -- 10/24/2007, 11:08 am