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Wisconsin Local Use Dimension Lumber Grading

The Wisconsin Local Use Dimension Lumber (WLUDL) grading certification was established under state statute 2007 Wisconsin Act 208. The purpose of this certification is to allow the use of locally milled dimension lumber in one- and two-family residential construction. By completing the training program and passing the associated exam, participants are given the proper training and certification to mill and sell lumber under the local use dimension lumber grading system. Certification is valid for five years, after which recertification is required by completing another course.

To register for a class, please visit our training and events page or the University of Wisconsin - Stevens Point's Forestry Center.

Frequently asked questions

How long is the course?
WLUDL classes start at 9:30 AM. Participants are usually finished with the exam by 3:00 PM the same day.
Is there a registration fee?
There are no registration fees or costs associated with the course.
What types of buildings does this apply to?
This certification is intended for lumber used in one- and two-family residential construction. The WLUDL grades are substitute equivalents of the lumber specified in the building code for those residential applications. For non-dwelling outbuildings, please refer to your local building codes regarding lumber requirements.
What lumber products fit this grading system?
The WLUDL certification focuses on dimension lumber. Dimension lumber is material nominal 2-inch thickness up to, but not including, nominal 5-inch thickness, and of nominal 2-inch or greater width.
This grading system does not apply to boards (less than nominal 2-inch thickness), or lumber designated as timbers which are often 5 inches thick or thicker.
What tree species can be used for this lumber?
Any commercial tree species can be used if it meets WLUDL grading requirements. When lumber is sold, the species must be documented in the WLUDL certification paperwork.
Do participants get a grade stamp upon completion of the course?
No. According to 2007 Wisconsin Act 208, grade stamps must not be placed on lumber milled and/or sold under WLUDL certification. In no way should any WLUDL markings resemble accredited grading agency stamps. This is to avoid any confusion between local use lumber and grade stamped lumber.
How do I explain this to my building inspector?
It is recommended to communicate your intention to use local use lumber with building inspectors as soon as possible. 2007 Wisconsin Act 208 clearly states that the building inspector has final authority and can approve, modify or reject any building plans. Certification required by 2007 Wisconsin Act 208 includes a valid WLUDL certificate issued to the person milling local use lumber as well as paperwork documenting the grades and condition of the lumber. A blank copy of the WLUDL paperwork is listed in the resources below.
How does local use lumber compare to grade stamped lumber graded under an accredited grading agency?
Generally, characteristics and limiting provisions for knots, holes, unsound wood and wane under the WLUDL grades are approximately the same or in many cases more restrictive compared to the requirements for grade-stamped dimension lumber. The WLUDL grading rules have been simplified compared to traditional industry grading rules. As a result, the grading rules have become more limiting to what will make the minimum grade standards. For instance, the maximum allowable knot size is smaller with WLUDL grades than with the comparable industry standard grades.
The appearance features of local use graded lumber are graded to less restrictive standards than industry comparable grades. This is because of the different scales of equipment being used to produce the lumber under the different grading systems.