Hardwood Flooring Stock Grades: NWFA and NOFMA Names, Lengths and the EN 14342 Note

Flooring stock is graded by how it looks, not by how much clear wood a board yields, and the grade names are set by flooring rules, not by the lumber rulebook. For unfinished solid strip and plank flooring in North America, the document buyers name is the NWFA/NOFMA standard. This page lists its grade names, the length minimums, the moisture range and the packaging marks, then explains where EN 14342 fits for European buyers.

Grade (oak)	What the standard describes	Average board length, strip under 3 in	Average board length, plank 3 to 5 in
Clear	Mostly heartwood, few character marks, uniform look	36 in	36 in
Select	Heartwood and sapwood color variation, small tight knots, pin worm holes	33 in	32 in
No.1 Common	Prominent color variation and varying characters	30 in	28 in
No.2 Common	Sound natural variation and milling imperfections, a rustic floor	24 in	24 in

Figures are from the April 2018 revision of the NWFA/NOFMA standard for unfinished solid flooring. The standard is revised from time to time. Name the edition in the contract. Board length minimums apply to shipments of 1,000 sq. ft. or more, and no single piece may be shorter than 9 in.

Where flooring grades come from

The NWFA/NOFMA standard says it replaces all editions and revisions of the Official Flooring Grading Rules published by the Wood Flooring Manufacturers Association. It covers configuration (width, tongue and groove fit, end squareness), moisture, board length, packaging and the grade descriptions. Two kinds of certification exist: standard NWFA/NOFMA configuration, grade rules and names, and proprietary or special products registered with the NWFA office.

Three points shape how a buyer should read a flooring quote:

• Appearance only. The standard states that appearance alone determines the grades, and that all grades are equally strong and serviceable in any application.
• Higher grades admit nothing extra. Characters allowed in a higher grade are automatically accepted in lower grades.
• Off-grade allowance. The standard allows up to 5% of the pieces to be misgraded, counting only pieces below grade. The target is 100% on grade.

Our guide to unfinished versus prefinished flooring stock covers the choice of product form. This page covers the grade names.

Other species have other names

Oak uses Clear, Select, No.1 Common and No.2 Common. The standard names the grades differently for other woods:

Species group	Grade names in the standard	Notes
Oak (red and white)	Clear, Select, No.1 Common, No.2 Common	Grain sort may be marked plain, quartered or rift
Hard maple, beech, birch	Select and Better, No.1 Common, No.2 Common	Special Clear grades exist for maple (nearly ivory white, 95% sapwood on the face) and for beech and birch (red faced stock, 95% red faced)
Hickory and pecan	Select, No.1 Common, No.2 Common	No.2 is described as a rustic look

The board length guidelines apply to red oak, white oak, hard maple, beech, birch, hickory and pecan, ash, American black cherry and American black walnut. There is no board length compliance for flooring wider than 5 in.

Grain sorts for oak

The standard defines oak grain terms by share of the piece:

• Plain sawn or plain: may contain any mix of plain, rift and quartered grain.
• Quarter sawn: at least 50% of the piece must show quartered characteristics (growth rings 45 to 90 degrees to the face, grain lines mostly parallel to the length, ray flecks present).
• Rift sawn: at least 75% of the piece must show rift characteristics (growth rings 30 to 60 degrees to the face).
• Quarter and rift: a combination of the two.

If a design needs a quartered look, write “quarter sawn per the NWFA/NOFMA definition” on the order and not just “quartered”.

Moisture, shorts and packaging

• Moisture. Flooring is manufactured at 6% to 9% moisture content, with a 5% allowance for pieces outside that range, up to 12%.
• Machining tolerances are measured at the time of manufacture only. After that the flooring gains or loses moisture and the dimensions change. Nominal 3/4 in thickness is listed with a tolerance of 0.015 in.
• Shorts. Pieces 9 to 18 in long may be bundled together as 1 1/4 Shorts, graded by the same rules and packed in any grade. The average board length minimum for 1 1/4 Shorts is 15 in regardless of width or grade.
• Packaging. Certified flooring is identified on the back by company name, logo, mark or number. Bundles of standard grade flooring are marked with the official grade and the color or species. The standard’s example reads NOFMA Select RO.
• Square footage. Coverage per bundle must meet or exceed the stated square footage on average over a shipment of 1,000 sq. ft. or more. An end match allowance is not used in the coverage calculation.

Combined grades

Mills often sell “Select and Better” or “No.1 Common and Better” as one price. The standard says the lowest grade admitted must not be less than the lowest grade listed, and that the length minimum of the lowest grade listed sets the standard for the combined grade. So a Select and Better bundle can legitimately average 33 in in strip widths, not the 36 in of Clear. Ask for the share of each grade, as you would with lumber grades, and ask which board length minimum the quote assumes. Our guide to Selects and F1F lumber shows the same thinking for sawn boards.

The EN 14342 note

European buyers will meet EN 14342, Wood flooring and parquet, characteristics, evaluation of conformity and marking. Its scope is flat wood flooring and parquet for interior use, including fully enclosed public transport premises. It excludes bamboo, laminate and products made for enhanced tactile recognition. It is the basis for CE marking through its Annex ZA, so a product for the EU market normally carries a declaration of performance that lists characteristics such as reaction to fire, formaldehyde release class and pentachlorophenol content. Sample declarations from manufacturers show these entries. EN 14342 is not a grading standard: it does not define Clear or Select.

Two practical consequences:

1. A US-style grade name and a European CE document answer different questions. A bundle can be “Select” and still lack the document an EU buyer needs.
2. Confirm the edition and whether your product needs the declaration with your importer. The 2013 edition is listed by several standards bodies, and one catalogue lists a 2015 amendment, so check the status before you cite it.

Prefinished flooring

Factory-finished flooring has its own NWFA/NOFMA document. It is a separate standard from the unfinished one. This page does not cover it. Ask the mill which document its prefinished product follows.

Checks on delivery

1. Count bundles against the order and read the grade and color mark on each bundle.
2. Measure the length of a sample of boards and compute the average. Compare it with the minimum for the grade and width.
3. Check that no piece is shorter than 9 in, except in a Shorts bundle.
4. Read moisture on a sample and compare it with the 6% to 9% range.
5. Set aside pieces that look below grade and count them. More than 5% of the pieces is outside the standard’s allowance.

What a mill can say about itself

Hardwood Vendor does not grade flooring, certify mills or hold any NWFA/NOFMA certification. A mill that says its flooring is NWFA/NOFMA certified should show its certification and the document edition. Ask for it in writing and check it with the NWFA.

What to write on the RFQ

• Species and grain sort (plain, quarter sawn or rift sawn, per the NWFA/NOFMA definition).
• Grade name and whether it is a combined grade, with the share of each grade.
• Width, thickness and profile (tongue and groove, end matched).
• Average board length minimum and the standard edition.
• Moisture range and the share allowed outside it.
• Bundle marking: grade and color or species on every bundle.
• For EU delivery: the CE declaration or the reason it is not needed.

Send your lumber RFQ with the flooring grade and edition and we pass it to up to 3 mills or yards that supply flooring stock.

RFQ line: Red oak (Quercus rubra group), NOFMA Select and Better, 3/4 x 2 1/4 in strip, tongue and groove, end matched, 6-9% MC, NWFA/NOFMA standard edition named, bundles marked with grade and color.