American hardwood lumber grading Q&A series: article no. 4

November 2007
by Bob Sabistina, Grading consultant to the American Hardwood Export Council

This month's article will continue to answer questions I have received from buyers throughout the world. If you have a question regarding the rules for grading American hardwood lumber or if there is any other topic you would like to see in future articles pertaining to hardwoods from the USA, please contact me at: bshardwoods1@yahoo.com.

We recently received a shipment of No. 1 Common white oak and there seemed to be quite a few pieces where the edges were not square and the ends were not trimmed very well. What is the ruling regarding this type of lumber?

As you are probably aware, the grading rules for North American hardwood lumber fall under the guidelines established long ago by the National Hardwood Lumber Association (NHLA). The NHLA grades are based on the percentage of clear, defect-free wood available on the board. The No. 1 Common grade is required to yield a minimum of 66 2/3% clear, defect-free wood on the poor face of the board. Outside of this clear percentage, only the structural centre of the log (pith) is considered in determining the grade.

What you are describing sounds like wane, which is defined as bark or lack of wood. Wane is limited in the upper grades (Selects, FAS1Face, and FAS), but not limited in the Common grades. The thinking here is that the Common grades are designed to yield a limited number of shorter clear cuttings or pieces when the lumber is re-sawn in the manufacturing process. An edge or end that has wane present is calculated in the measurement of the board but not included in its yield. Paragraph 8 in the NHLA Rule Book talks about lumber production: “ It (lumber) should be edged and trimmed carefully to produce the best possible appearance while conserving the useable product of the log. If the supplier trimmed all the Common lumber to simply produce the best possible appearance, his yield would suffer which, in turn, would have a direct influence on the price. Most importantly is that the Common grades yield the buyer 66 2/3% and better clear area when run through the manufacturing process.”

I am always forced to buy random widths and lengths from American suppliers. Can I purchase fixed widths and lengths?

Yes, there are a number of AHEC suppliers that are doing special sorting for widths and lengths. The thing you must keep in mind is that a premium will be added to the price for this service. A careful study of your yields and waste factors through the factory will assist you in determining if it is worth the premium.
At this point, It is worth mentioning that special sorts can also be made for colour. Other than for hard maple, which has several colour sorts, which relate to the sapwood content (these were featured in my April Q&A series article), the NHLA rules do not address sapwood or heartwood colour sorts. However, many suppliers offer colour sorting in cherry, tulipwood, ash, even red oak. Working closely with your supplier, making sure you have a good understanding of regional differences and having a working knowledge of the hard maple sorts should allow you to specify sapwood or heartwood content that is workable for you and your supplier.

Please explain the difference between the FAS1Face and Selects grades.

The difference between these two upper grades is the required minimum size board. For FAS1Face (F1F), the required minimum size board must be the same as for FAS, for whatever species you are grading. For the most part this is a 6 inch wide and 8 foot long board. There are a few exceptions to this requirement which would also apply to the F1F grade. For example, FAS white hard maple needs to have a minimum size board of 4 inches wide and 8 foot long, which means that F1F white hard maple would also need to be 4" wide and 8' long. To meet the Selects grade, the requirement is a minimum size of 4 inches wide and 6 foot long. Other than this minimum board size, the grades are the same. Both need to yield FAS on the better face and not below No. 1 Common on the poor side.

Historically, the Selects grade has been primarily applied to the Northern United States and Canadian species. These regions of North America have shorter growing seasons than the rest of the country and generally produce slower growth, smaller diameter timber. As you move through the Midwest and Appalachian regions and, certainly, the Southern regions of the US, you are more likely to see the F1F grade being used.

Where can I get more information regarding the American grading rules?

The American Hardwood Export Council (AHEC) has offices in Shanghai, Hong Kong, London, Osaka, Japan, Mexico City and Washington DC. They hold grading workshops throughout the year which range from a couple of hours to several days. I have been working with them on this for over a year and the response received after each workshop is extremely positive. AHEC also distributes a range of free publications on species, products, lumber grading, structural properties and architectural references. You can contact them directly or email me for the location in your region.

The NHLA, which is located in Memphis, Tennessee has numerous publications including the official Rule Book available for a small fee. They also hold one of the most important courses for the North American hardwood industry at their Inspection Training School. This is an intense 14 week programme, which is held twice a year in Memphis. The course acts as a stepping stone for anyone interested in making a career in the hardwood industry. The student will not only learn the grading rules, but will also benefit from exposure to the workings of the trade and will make contacts that will last a lifetime. You can visit their website at: www.natlhardwood.org for more information.

Post Script: I started this column one year ago and from the emails I receive, there is a lot of interest in hardwoods from America. I encourage you to email me if you encounter any issues that might be of interest in future columns.

American Hardwood Export Council
The American Hardwood Export Council (AHEC) is the leading international trade association for the US hardwood industry, representing the committed exporters among US hardwood companies and all the major US hardwood product trade associations. AHEC concentrates it efforts on providing architects, specifiers, designers and end-users with technical information on the range of species, products and sources of supply.

AHEC produces a full range of technical publications which are available free of charge by visiting www.ahec-middleeast.org, www.sustainablehardwoods.info & www.americanredoak.info or by faxing (44) 20 7626 4222.
For more press information/photography, please contact: Lucy Peacock / Melissa Green, Email: lucy.peacock@ahec.co.uk / Melissa.green@ahec.co.uk.