Milled vs. Rough lumber prices?

[Tom Jones III]

I'm confused, I'm planning out a rather large (for me anyway) project and am trying to determine the least expensive way to buy the lumber. I got a price sheet from one of the leading hardwood lumber companies in town. Their prices are in line with everyone else, sometimes a few pennies cheaper and they are the only ones who publish a price sheet.

Anyway, my assumption is that rough lumber takes less effort for the lumber company, so it should be cheaper. That appears to be wrong:

Rough Walnut, 4/4 is $4.60 bd/ft
Milled Walnut 1x6 (.75" x 5.5") is $3.55 per lineal foot.

An example using an 8' board:
((1 * 6)/12) * 8) * $4.60 = $18.40 (4 rough board feet)
Mill that rough piece down to standard size, and you get
((.75 * 5.5)/12 * 8) = 2.75 ft.

$18.40/2.75 ft = $6.69 per lineal foot for the rough board.

If you were to buy that same 8' board already milled to standard 1x6 size,
((.75 * 5.5)/12 * 8) * 3.55 = $9.76

So, if my calculations are correct, you are paying roughly 88% more so that you can mill it yourself! I don't understand, I would assume that the more you do yourself, the cheaper it is. Surely I'm doing something wrong.

[Rob Russell]

Tom,

Your calculations are partially correct, but not totally.

The board foot calculation of the rough stock is fine. Assume 4/4 stock, 6" wide x 8' long = 4 board feet * $4.60 = $18.40. I agree.

Buy the same board already dimensioned, 3/4" thick x 5.5" wide x 8' long and the price is $3.55/lineal foot. That means 8' * $3.55 = $28.40.

When you buy wood by the lineal foot, it doesn't matter how thick, thin or wide the wood is - just how long the stock is.

As you can see, it's more than 50% more expensive to buy the milled lumber ($28.40 - $18.40)/$18.40.

Rob

[Rick Lizek]

To keep it simple I'm using the bd ft vs lin ft.
One bd ft is 1" x 12" x 12" at $4.60
At the lineal price it's a 6" x 12" so double it to make it the same thing... 12" x 12" = $7.10 a square foot which compares to a bd ft so it is cheaper to buy rough as it should be.

[Scott Loven]

Rough Walnut, 4/4 is $4.60 bd/ft
Milled Walnut 1x6 (.75" x 5.5") is $3.55 per lineal foot.
1 lineal foot is 1/2 board foot in this case
Milled price is per lineal foot not board foot. In this case they would take a 1'*6'*( ) board and mill it down to .75"*5.5"*( ). So in this case your price would be $7.10 per board foot for milled lumber.

[Dan Forman]

Here is a page which should clear up the mystery. http://www.cwc.ca/design/tools/calcs/board_feet/

The problem is that board feet and linear feet are calculated differently.

A 1x6 board 10 feet long would be 5 board feet.

The same board would be 10 linear feet.

Dan

Looks like a few responses got in while I wasn't looking!

[Tom Jones III]

Thanks guys, I knew I had something wrong.