Clarifying Surfacing to Standard Rough Thickness
-By NHLA Chief Inspector, Dana Spessert
The NHLA Inspector Training School is currently holding its 193rd Class for lumber inspectors. The students, at the time of this article, are in the 6th week of class. They are currently learning that hardwood grading is all about mathematics and defect identification.
One of the things that I have always found interesting is the varying ways that the students read and understand the Rules as progress through the learning process. This class is no different.
As the students practiced on “board runs,” one of the Rules began to be utilized in differing ways. The Rule I am referencing is on page 4, paragraph 4, under General Instructions of the NHLA Rules Book, and it states: “Lumber shall be inspected and measured as the inspector finds it, of full length, width, and thickness. No allowance shall be made for the purpose of raising the grade, except that in rough stock, wane, and other defects which can be removed by surfacing to standard rough thickness shall not be considered. Nothing herein shall be construed as prohibiting the shipper from improving the grade or appearance of the lumber at the time of or prior to shipment.”
As it’s written in the second sentence, “wane, and other defects which can be removed by surfacing to standard rough thickness shall not be considered,” there are times that defects can be admitted in the Clear Face Cuttings. This Rules can be over-utilized and cause significant issues. Let me explain with a few examples.
- The board is 4/4 (1”) thick as Standard Rough Thickness, and it measures 1.125” rough. The over thickness is equal to 1/8” (0.125), and many inspectors will assume that they can remove any defect if it is equal to or less than 1/8” in thickness. Although there may be times that this is true, the only definite way would be to actually surface the board and then determine if it was removed. I would like to suggest that the inspector allows for variations in the opposite face for tooth marks and wood fibers that could cause the board not to clean up as much. It is a good “rule of thumb” to only assume half of the over thickness will be removed, making this a sure thing to consider.
- There is a very small pin knot that is questionable between a pin knot or burl. I suggest turning the board over and verifying if it is a knot on the opposite face; if it is, it will not surface off. Instead, it would most likely get bigger. In this case, I would not even consider that this would be surfaced off as “other defects,” stated in paragraph 4 above.
The main role of NHLA is to provide a uniform set of Rules for trading hardwood lumber, and we are very honored to do so. NHLA will soon be announcing requests for Rules proposals for additions, deletions, or changes to the current Rules, as we do every four years. It was in 2017 when we last requested rules change suggestions from the industry, and we will begin again in 2021. All Rules change proposals will be sent to the NHLA Chief Inspector to collect for a Rules Committee meeting held in the Spring of 2021.
If you have any questions, please reach out to me at [email protected].