Hardwood Floors: Grading from High to Low

Hi all,

The world of wood grading can be a very confusing one. Systems and rules change from continent to continent and from species to species. In this global economy, it’s difficult to keep it straight. Here I’ve developed a bit of a cheat sheet to give you an idea as to what you can expect as grades go from high to low. Please keep in mind that this is by no means exact and does not correspond with any one grading system.

Cheers,

Tom

American Walnut:

A Grade:

1. Color ranges from a deep, rich dark brown to a purplish black. 2. Sapwood is not allowed. Wood knots can not be over 5mm.

3. Slight Mineral Streaks allowed (less than ¼” wide and 3″ long).

4. 92% clear & better.

AB Grade:

1. Color ranges from a deep, rich dark brown to a purplish black.

2. Sapwood is allowed. Wood knots can not be over ½” in diameter.

3. Mineral streaks allowed.

4. Minor imperfections in machining permitted.

5. 75% clear & better.

ABC Grade:

1. Color variation and natural characteristics of the wood are apparent.

2. Sapwood is allowed. Wood knots can not be over 2/3″ diameter.

3. Knot Holes, Bird Pecks, Worm Holes and the like are allowed.

4. 50% clear & better.

ABCD Grade:

1. Color variation and natural characteristics give a ” rustic ” appearance.

2. Sapwood is allowed.

3. Wood Knots or any open characters which will readily fill are admitted.

4. 35% clear & better.

Jatoba:

A Grade:

1. Color ranges from Salmon red to orange-brown when fresh.

2. Slight Sapwood and Mineral Streaks are allowed.

3. Moderate color variation.

4. 92% clear & better.

AB Grade:

1. Color ranges from Salmon red to orange-brown when fresh.

2. Sapwood (gray-White) is allowed. Wood knots can not be over 5mm.

3. Slight Mineral Streaks are allowed.

4. Moderate to high color variation.

5. 80% clear & better.

ABC Grade:

1 Moderate to high color variation from honey brown to Salmon red.

2. Sapwood and wood knots allowed, wood knots can not be over ½” in diameter.

3. Mineral Streaks are allowed.

4. 60% clear & better.

Santos Mahogany:

A Grade:

1. Color ranges from red to dark red, moderate color variation.

2. Slight Sapwood, Mineral Streaks and Wood knots are allowed.

3. 92% clear & better.

AB Grade:

1. Color ranges from red to dark reddish brown, moderate to high color variation.

2. Sapwood is allowed. Wood knots can not be over 5mm.

3. Slight Mineral Streaks are allowed.

4. 80% clear & better.

ABC Grade:

1. Moderate to high color variation, natural characteristics apparent.

2. Sapwood is allowed. Wood knots can not be over ½” in diameter.

3. Mineral Streaks are allowed.

4. 60% clear & better.

White Oak:

A Grade:

1. Color: Heartwood is light brown; some boards may have a pinkish tint or a slight Grayish cast. Overall a uniform appearance.

2. Minimal number of character marks and discoloration allowed.

3. 92% clear & better.

AB Grade:

1. Color: Heartwood is light brown; some boards may have a pinkish tint or a slight

Grayish cast. Sapwood is white to cream.

2. Slight imperfections in face work, some machine burn, mineral streaks and brown streaks are

allowed. Wood knots can not be over 5mm.

3. 70% clear & better.

ABC Grade:

1. Color: Prominent variations with varying characters.

2. Sapwood and Mineral Streaks are allowed.

3. Wood knots under ½” in diameter.

4. 50% clear & better.

ABCD Grade:

1. Natural wood grain and slight manufacturing imperfections allowed.

2. Large broken knots or unsound defects allowed.

3. 35% clear & better.

Oak Grain: Open, with longer rays than red oak Occasional crotches, swirls and burls. Plain sawn boards have a plumed or flared grain appearance; rift sawn has a tighter grain pattern, low figuring; quarter-sawn has a flake pattern, sometime called tiger rays or butterflies.

Red Oak:

A Grade:

1. Color: Most pieces have a reddish (pinkish) tone. Slightly redder than white oak.

2. Minimal number of character marks and discoloration allowed.

3. 92% clear & better.

AB Grade:

1. Color: Heartwood and sapwood are similar, with sapwood lighter in color.

2. Slight imperfections in face work allowed.

3. Some machine burn, mineral streaks and brown streaks are allowed.

4. Wood knots can not be over 5mm.

5. 70% clear & better.

ABC Grade:

1. Color: Prominent variations with varying characters.

2. Sapwood is allowed.

3. Mineral streaks are allowed.

4. Wood knots under ½” in diameter.

5. 50% clear & better.

ABCD Grade:

1. Natural wood grain and slight manufacturing imperfections allowed.

2. Large broken knots or unsound defects allowed.

3. 35% clear & better.

Variations within species and grades: More than 200 subspecies in North America; great variation in color and grain, depending on the origin of the wood and corresponding differences in growing seasons. Northern, Southern and Appalachian red oak can all be divided into upland and lowland species. Because they grow more slowly, upland species generally have a more uniform grain pattern than lowland species, with more growth rings per inch.

Hard Maple:

A Grade:

1. Color: Most pieces are creamy white to light reddish brown.

2. Practically free of defect, slight pin knots and streaks allowed.

3. 92% clear & better.

AB Grade:

1. Color: Most pieces are creamy white to light reddish brown. Sapwood is pale to creamy white.

2. Numerous Dark Green, Black Spots or Streaks are allowed.

3. Small rough spots are allowed.

4. 80% clear & better.

ABC Grade:

1. Maple characteristics and color variations.

2. May contain all defects common to Maple.

3. Knot holes under 1/2″ in diameter allowed.

4. 50% clear & better.

ABCD Grade:

1. Color variation and natural characteristics of the wood are apparent.

2. Wood Knots or any open characters which will readily fill are admitted.

3. 35% clear & better.

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