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Art Bryan
Art Bryan is president and owner of Southwestern Remodeling Contractors, Inc. Art started Southwestern Remodeling Contractors in 1970. Southwestern is a fully-licensed residential and commercial licensed general contractor in Wichita and the surrounding counties. Art has been a member of the Wichita Area Home Builders Association and the National Remodel Council since 1974. In mid-2000 Southwestern received the distinction of being named one of the "Top 25 Most Diversified Remodeling Companies in the United States.” Southwestern is listed as the 84th Top Remodeler in the country by Qualified Remodeling Magazine. Art can be contacted at his office at (316) 263-1239, fax at (316) 263-6230, or you can e-mail him at ARTSWR@aol. Com
Home Improvement
2003-08-01 11:28:00
How is lumber graded?
: How is lumber graded? 
ANSWER: Lumber is graded in one of two classes, softwood construction lumber and hardwoods.  It's a bit technical but I will give it my best shot. Softwood Construction Lumber   Most softwoods (though certainly not all) that are made into finished boards are intended to be construction lumber.  This material is generally sold according to it's "nominal" dimension, typically 1-by something or 2-by something.  Minimum thickness for planed, dry 1-by material is 3/4"; dry means average moisture content of 12%, maximum of 15%.  Minimum thickness for 2 by material (planed and dry) is 1-1/2".  For wet or "green" lumber (this includes formerly dry material that has been allowed to take up water and has not re-dried) minimum surfaced thickness is 25/32" and 1-9/16" for 1-by and 2-by material, respectively.  For widths, the rules are the same for both 1-by and 2-by material.  For widths up through 7 inches, the minimum dry, planed width is 1/2" less than the nominal dimension.  So, dry 1x6 and 2x6 material should both be 5-1/2" wide.  For widths of 8" and above, the width should be 3/4" less than the stated dimension (e.g., 1x10 should be 9-1/4" wide).   Grading softwoods is complex (though not as bad as hardwoods) and it depends on the use (boards versus structural lumber), and the type and distribution of defects (tight knots, loose knots, spike knots, wane, shake, etc.).  There are several different grading authorities, but the board grades most common in the U.S. are (in decreasing order of "quality") finish or select, #1 (common), #2 (common), #3 (common), and #4 (common).  Structural lumber generally uses different terminology including such things as #1, #2, and #3 structural, superior, stud, utility, and several others.  Ask your lumber dealer to explain the system by which their lumber is graded; there is a lot of variation from dealer to dealer.  The "Encyclopedia of Wood" has pictures of the board grades; Hoadley's book may also, I don't recall.Hardwoods   Standard thicknesses for hardwood lumber are as follows (in inches):
 
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