Conference 7.286::home_work

    Can you put the term "linear foot" in context?

    re:.1  Sure, I was looking at some new counter tops for our kitchen.
    The price was $4.99 a linear foot.
    
    does that help?
    

    It simply means the cost is per foot of length. It is not dependent
    on the width.

           -< What about a "board foot"? >-
1 board foot :== 12 inches x 12 inches x 1 inch

The 1 inch is the unplaned measure so finished thickness is
a little thinner.

    thanks people.
           Appreciate the info.
    
    Gary
    

    When I was buying hardwood strip flooring, the guy at the store
    said you have to add 40% to a board foot to get a square foot;
    
    something like the reason being that they measure the square foot
    using 3" wide boards when in reality they are only 2 1/4" wide.
    Similar to a 2x4 not being 2"x4"
    
    -al

    and while we're at it, how 'bout hardwood sizing, as in 6/4...

Here's how I figure it..

Board feet are measured in "nominal" sizes.  A board foot is a "nominal" square
foot of wood a "nominal" inch thick.  An example of a board foot is a 1 foot 
long section of 1x12.  This would be 3/4" thick, by 11 1/2" wide by 1 foot long.
Another example is a six foot section of 1x2.  Since the 1x2 is only 3/4 by 
1 1/2, there's more wood in a board foot of 1x12 than in a board foot of 1x2.

Board feet are right up there with nail sizing in "pennies" in the all time 
"let's confuse the novice" contest.

I've always been charged based on "nominal" board feet whether buying softwood
or hardwood.  I don't think there's a difference.

The sizes for wood are simply the size that they are cut at the sawmill.  If 
you buy a roughsawn 1x12 at your local mill, it will be a full 1"x12".  If you 
buy it green, that is.  When it dries, it shrinks, and when they plane it, it 
gets even smaller.  The shrinkage is why the one inch dimension is only �" 
smaller than nominal, but the wider dimension is �" narrower than nominal.
BTW, anything from 1x8 and up is 3/4" narrower than nominal - the wider boards 
have more shrinkage, so a 1x12 is actually 3/4x11�.  If you were able to get a 
1x16, it would probably be 15" wide after drying and planing.

With planed wood, you definitely get less wood per board foot in the narrower 
widths, but this is simply because more edges have been planed.  On one board 
foot of 1x12, two feet of edges have been planed, on the equivalent 1x2, 12 feet
of edges have been planed, so of course more of the wood is gone.

Also, it's even worse for something like hardwood flooring, because they have 
to cut a tongue and groove in the edge, and that takes even more wood, so 
instead of being 2�" wide it's 2�".

Nominal values are used simply because they are easier.  "I'd like a 6 foot 
3/4x7�, please" is more confusing than asking for a 1x8.

6/4 etc refers to quarters of an inch.  4/4 is one inch thick, 6/4 is 1�" thick.
Nominal, of course. :^)

Paul

    I just went to the glass shop to look for storm windows and asked
    how much it would be.  They said 24 cents per *united inch*.
    A what?
    
    As they explained, a united inch is the sum of the length and width
    along 2 sides.  Something new every day...
    
    -al

    The comment that one board foot is 40 percent of a square foot
    is allowing for a combination of two things:  the wood lost
    while milling the tongue & groove, and waste when installing the
    floor.  To put down a 100 square foot floor a professional would
    buy 560 linear feet of boards, assuming they're just the narrow
    oak type.  
    

    
    
    	Does anyone know how Board/ft calculated?
    
    	I need three boards, 3.5 " X 8" X 18'.
    
    	Thanks......
    
    
    
    

    I believe that "board feet" is simply the length of the board, so just
    add up the lengths.  If you are ripping them from a larger board, then
    you have some calculating to do.
    
    Mark

    This is the way I learned it: A board foot is a 12" length of 1x12.  
    Therefore, a board foot of 1x8 is 18".  So, if you need three 18'
    lengths of 1x8, that's (18x3)=54;(54/1.5)=36 board feet.
    
    Of course, if I'm wrong, my colleagues here will correct me.
    
    					{^% andrew %^}

    Yes, a board foot is 144 cubic inches of wood, typically represented
    by a 1"x12"x12" board...or a 1"x6"x24" board...or whatever other
    combination gives you 144 cubic inches of wood.  (Of course, a
    1x12 isn't really 1x12, and a 1x6 isn't really a 1x6, and all that,
    but assume they are....)

so 3.5" X 8" X 18' = 6048 cubic inches / 144 = 42 board feet

3 of em is 126 bf, at say $4.00/bf... ain't woodworking fun? :-)

Mike

    
    
    	That makes sense.  It is $1. per bd/ft and the price for the three
        them is $125.00
    
    	Thanks folks...

    Of course, if that 3.5" is 4X, then it's 4x8x(18x12)=6912 /144 = 48;
    three lengths will be 144 board feet.

	..... and of course the topic of board feet has been discussed
	before (under the guise of the "hardwood flooring" topics) ......

    
            And of course, if I were doing hardwood flooring instead of
            ordering rough cut beams, I wouldn't have bothered searching
            DIR/TITLE="*calculation*"  
    	    DIR/TITLE="*BOARD*"
            DIR/TITLE="*FEET*" 
    
		And...  mods, feel free to move this if it is not itn the
    	        right place. ;-)
    

> And of course, if I were doing hardwood flooring instead of
> ordering rough cut beams, I wouldn't have bothered searching

	.... which is why I said "under the guise" (ie. it's not an
	obvious place to be looking for the info)