D03E - MATERIAL GUIDES - GRADES

D03E-1 Hardwood grading
D03E-2 Solid hardwood grading
D03E-3 Imported / exotic wood grading
D03E-4 Engineered hardwood grading
D03E-5 Choosing the right grade
Preface:
This study guide covers grading of hardwood material for solid and engineered hardwood strip, plank, and parquet flooring. The information given is a guide only and must be verified with the applicable grading authority as well as with local suppliers
1 • HARDWOOD GRADING
.01 With the advent of hardwood floor manufacturing machinery and the demand for solid hardwood flooring, a need to implement standards and grading of materials arose. This resulted in the formation of various product manufacturing associations and a degree of consistency of products from these different producers. These industry associations developed minimum criteria encompassing such things as material qualities and grades, surface characteristics, milling tolerances, and required lengths. Such Associations have also now established installation, inspection, and dispute resolution guidelines, as well as promotion / marketing of their materials.

.02 An important point to note is that most wood flooring grades deal with appearance or aesthetics and not serviceability. In this regard most grades will perform equally well, it is only their facial appearances that vary. One factor that can affect this appearance is the way the material is cut from the log itself. Plain sawn flooring will show great variation in grain patterns on the surface of the floor. Rift or quarter-sawn flooring will have a relatively uniform grain pattern. As a result this appearance affects the grading of such material. A higher grade flooring therefore is not necessarily "better", it is just a matter of appearance and personal taste. As well, character marks not accepted in higher grades are automatically accepted in lower grades.

.03 Another grading factor is that most grading rules also dictate the average length of the boards in each grade with higher grades of flooring usually having longer boards and lower grades having many shorter boards. A good example of how this works is using NWFA (NOFMA) grading rules for solid oak flooring which has four levels - Clear, Select, #1 Common, and #2 Common. Clear grade oak is very uniform in colour, with very few small character marks and has an average board length of 1070 mm (42"). Select oak has more colour variation and more natural character marks such as small knots with an average board length of 990 mm (39"). #1 Common oak has a much more varied appearance, with mineral streaks, greater colour variation, and more character marks, and an average board length of 840 mm (33"). The last grade, #2 Common, has a "rustic" appearance, with just about any natural character mark, including large knots, and very dark boards included.
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Clear Grade
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Select Grade
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#1 Common Grade
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#2 Common Grade
.04 It must be noted however that because the characteristics of wood species and types of wood flooring vary so much, there are no standard grades for all hardwood flooring materials. This is particularly evident with other non-typical domestic wood species and with manufacturers who are not members of the grading associations. This has resulted in some of these manufacturers creating their own "proprietary" grades. In addition, the countries of origin and/or manufacturers of imported wood species may have established their own grading rule standards for this material that will vary from the noted North American CLA, NWFA (NOFMA), MPMA, or SPIB grading rule standards.

.05 There are no grading standards for engineered hardwood wood flooring other than manufacturing criteria. Because of this, most manufacturers of engineered flooring have developed their own "grades" that for the most part are product or brand names based on veneer, finish, and milling. Generally, such manufacturers' product names reflect three levels or more of quality - ranging from a premium level grade down to what is generically referred to as cabin grade. At the premium grade level the flooring has almost no milling defects and minimal character marks such as knots, mineral streaks, or pin worm holes. The next grade, typically a character grade, allows more natural character marks and some minor milling defects that may cause overwood, small finish skips and shorter average lengths. The lowest, or cabin-grade, allows unlimited character marks and milling defects. In addition while most solid wood flooring products have average length requirements, most engineered floors do not.

.06 Because wood is a natural material, no two boards are going to be the same. Thus, a floor of one grade or brand name may appear slightly different than another floor of the same brand name. For an accurate representation of what different grades will look like, it is vital to view a large sample of the floor before any ordering of material takes place. This should ensure that the end user's expectations don't clash with the reality of the installed flooring material.
2 • SOLID HARDWOOD GRADING
.01 Grading Authorities:
  1. Various North American hardwood flooring material manufacturers associations have established their own grading rules (grades) for the domestic species of solid hardwood flooring that their member manufacturers produce. Some of these Associations are as follows:
    1. Canadian Lumbermen's Association (CLA).
    2. Quebec Wood Export Bureau (QWEB).
    3. National Oak Flooring manufacturer's Association (NOFMA).
    4. Maple Flooring Manufacturers Association (MFMA).
    5. Southern Pine Inspection Bureau (SPIB).
  2. Each of the above noted Associations have their own grading rules as follows:
.02 The Canadian Lumbermen's Association (CLA) has established grading rules for northern hard maple, Canadian birch, northern red and white oak, and parquet flooring as follows. Now available through The Ontario Forest Industries Association 
1.   CLA Graded Northern Hard Maple and Canadian Birch:
  • First Grade Northern Hard Maple / Clear Grade Canadian Birch.
  • Second Grade Northern Hard Maple / Select Grade Canadian Birch.
  • Factory Grade Northern Hard Maple / Third Grade Canadian Birch.
Combination Grades:
  1. Shorts.
  2. Prime Northern Hard Maple / Second and Better Northern Hard Maple.
  3. Select & Better Canadian Birch.
  4. Third & Better (Mill Run Grade).
  5. Plank Flooring
2.   CLA Graded Northern Red and White Oak:
  • Plain Sawn Clear Grade.
  • Plain Sawn Select Grade.
  • #1 Common Grade.
  • #2 Common Grade.
Combination Grades:
  1. Shorts.
  2. Select and Better.
  3.  #1 Common & Better (Mill Run Grade).
  4. Plank Flooring.
3.    CLA Graded Parquet Flooring:
  1. Select and Better Grade.
  2. Natural Grade.
  3. Rustic Grade.
4.    CLA Grading Criteria: For a thorough explanation of CLA criteria for each grade refer to the CLA publication "Canadian Hardwood Flooring - The Long Standing Choice (grading rules)" or the CLA website at www.cla-ca.ca, or NOFMA website at www.nofma.org.
.03 The Quebec Wood Export Bureau (QWEB) has established grading rules for wood strip and parquet flooring as follows:
1.    QWEB Graded Hard Maple, Yellow Birch, Red Oak, White Ash, Beech, Cherry, and Walnut Strip Flooring:
  1. Clear Grade.
  2. Select and Better Grade.
  3. #1 Common Grade.
  4. #2 Common Grade.
.04 The National Wood Flooring Association (NWFA) and National Oak Flooring Manufacturers Association (NOFMA) has established grading rules for pre-finished oak and unfinished oak, beech, birch, hard maple, hickory/pecan, and ash as follows:
1.    NWFA (NOFMA) Graded Unfinished Red and White Oak:
  1. Clear Oak.
  2. Select Oak.
  3. No. 1 Common Oak.
  4. No. 2 Common Oak.
  5. 1 1/4' Shorts Oak.
2.    NWFA (NOFMA) Graded Pre-Finished Red and White Oak:
  1. Prime Pre-finished Oak.
  2. Standard Pre-finished Oak.
  3. Standard & Better Pre-finished Oak.
  4. Tavern Pre-finished Oak.
  5. Tavern & Better Pre-finished Oak.
3.    NWFA (NOFMA) Graded Beech, Birch and Hard Maple:
  1. Select & Better Beech, Birch & Hard Maple.
  2. No. 1 Common Beech, Birch & Hard Maple.
  3. No. 2 Common Beech, Birch & Hard Maple.
  4. No. 1 Common & Better Beech, Birch & Hard Maple.
  5. No. 2 Common & Better Beech, Birch & Hard Maple.
  • Special Grades:
    1. Clear Hard Maple Grade.
    2. Clear Beech and Birch.
4.    NWFA (NOFMA) Graded Hickory and Pecan:
  1. Select & Better Hickory / Pecan.
  2. No. 1 Common Hickory / Pecan.
  3. No. 1 Common & Better Hickory / Pecan.
  4. No. 2 Common Hickory / Pecan.
  5. No. 2 Common & Better Hickory / Pecan.
  • Special Grades:
    1. Clear Red Hickory / Pecan.
    2. Clear White Hickory / Pecan.
5.    NWFA (NOFMA) Graded Ash:
  1. Clear Ash.
  2. Select Ash.
  3. No. 1 Common Ash.
  4. No. 2 Common Ash.
6.    NWFA (NOFMA) Graded American Black Cherry: (Prunus serotina Ehrh.)
  1. Clear Cherry.
  2. Select Cherry.
  3. No. 1 Common Cherry.
  4. No. 2 Common Cherry.
7.    NWFA (NOFMA) Graded American Black Walnut: (Juglans nigra L)
  1. Clear Walnut.
  2. Select Walnut.
  3. No. 1 Common Walnut.
  4. No. 2 Common Walnut.
NWFA (NOFMA) Grading Criteria: For a thorough explanation of NWFA and NOFMA criteria for each grade refer www.nwfa.org
.05 The Maple Flooring Manufacturers Association (MFMA) has established grading rules for northern hard maple as follows:
1.    MFMA Graded Northern Hard Maple Finger Jointed (FJ) Strip Flooring:
  1. First Grade Northern Hard Maple.
  2. Second and Better Grade Northern Hard Maple.
  3. Third and Better Grade Northern Hard Maple.
  4. Third Grade Northern Hard Maple.
  5. Utility Grade Northern Hard Maple.
2.    MFMA Graded Northern Hard Maple Random Length (RL) Strip Flooring:
  1. First Grade Northern Hard Maple.
  2. Second and Better Grade Northern Hard Maple.
  3. Third and Better Grade Northern Hard Maple.
  4. Third Grade Northern Hard Maple.
  5. Utility Grade Northern Hard Maple.
3.   MFMA Graded Northern Hard Maple Parquet (PQ) Flooring:
  1. First Grade Northern Hard Maple.
  2. Second and Better Grade Northern Hard Maple.
  3. Third and Better Grade Northern Hard Maple.
  4. Third Grade Northern Hard Maple.
4.    MFMA Grading Criteria: For a thorough explanation of MFMA criteria for each grade refer to the MFMA website at www.maplefloor.org
.06   The Southern Pine Inspection Bureau (SPIB) has established the following grading rules for solid strip and plank Pine flooring:
  1. B and Better Grade.
  2. C Grade.
  3. C & Better Grade.
  4. D Grade.
  5. No. 1 Grade.
  6. SPIB Grading Criteria: For a thorough explanation of SPIB criteria for each grade refer to the Southern Pine Council website at www.southernpine.com.
3 • IMPORTED / EXOTIC WOOD GRADING
.01 Many hardwood and some softwood species are imported for use as hardwood flooring material. The manufacturers of these materials and their countries of origin may or may not have their own grading rules. The design authority must verify all grading requirements for the species selected with the supplier of these materials.
4 • ENGINEERED HARDWOOD GRADING
.01 There are a number of engineered hardwood flooring manufacturer associations that have established their own grading rules (grades) for the products that their member manufacturers produce. The design authority must ensure that they use the appropriate Association grading requirements for the system materials that they select. Some of these Associations and their grades are as follows
.02 The National Oak Flooring Manufacturers Association (NOFMA) has established the following grading rules for engineered flooring:
1.   NOFMA Graded Unfinished Oak Engineered Flooring:
  • Select & Better Unfinished Oak Engineered Flooring Grade.
  • No. 1 Common Unfinished Oak Engineered Flooring Grade.
  • No. 2 Common Unfinished Oak Engineered Flooring Grade.
2.   NOFMA Graded Pre-finished Oak Engineered Flooring:
  • Prime Engineered Oak Flooring.
  • Character Engineered Oak Flooring Grade.
  • Cabin Engineered Oak Flooring Grade.
.03 Note: Laminate flooring should not be confused with engineered flooring (sometimes referred to as laminated flooring). Refer to Part E03C - Material Guide(Laminate Flooring) for a description of this type of flooring material.
5 • CHOOSING THE RIGHT GRADE
.01 The design authority must ensure that they use the appropriate Association and grade for any domestic hardwood material that they select. In the case of imported species the design authority must verify grading requirements with the supplier. As well, in all cases the grade content and minimum average lengths for bundles of a selected species and grade must be verified with the particular grading association or supplier.
Caveat Emptor – Buyer Beware

Not all manufacturers of hardwood flooring are members of the grading associations noted herein. Some of these manufacturers produce hardwood lumber and assign their own grading classifications or proprietary names to them. This may be for marketing purposes or because there isn't an Association classification for their specific products. Some of these grades may even have similar names but have different grading criteria. In all cases the design authority must verify the grading criteria to ensure that the product installed will meet the design criteria and expectations of the end user.
END OF SECTION