Top portion is finished with water-base urethane; bottom with oil-modified polyurethane.

Appearance

Color: In yellow birch (B. alleghaniensis), sapwood is creamy yellow or pale white; heartwood is light reddish brown tinged with red. In sweet birch (B. lenta), sapwood is light colored and heartwood is dark brown tinged with red.
Grain: Medium figuring, straight, closed grain, even texture. Occasional curly grain or wavy figure in some boards.
Variations within species and grades: Yellow birch, sweet birch, paper birch. Paper birch (B. papyrifera) is softer and lower in weight and strength
than yellow or sweet birch. However, yellow birch is most commonly used for flooring. Boards can vary greatly in grain and color.

Properties

Hardness (Janka): 1260 (yellow); 2% softer than Northern red oak.
Dimensional Stability: Average (change coefficient .00338; 8% more stable than red oak).
Durability: Hard and stiff; very strong, with excellent shock resistance.

Workability
Sawing/Machining: Difficult to work with hand tools, but good machining qualities.
Sanding: Sands satisfactorily.
Nailing: Excellent holding ability.
Finishing: No known problems.