Douglas Fir

Douglas Fir Wood Flooring
Sample above is .75" by 3.25" inch square-edge solid strip. Top portion is finished with water-base urethane; bottom with oil-modified polyurethane.
Appearance

Color: Heartwood is yellowish tan to light brown. Sapwood is tan to white. Heartwood may be confused with that of Southern yellow pine. Radical color change upon exposure to sunlight. 
Grain: Normally straight, with occasional wavy or spiral texture. Nearly all fir flooring is vertical-grain or riftsawn clear-grade material. 
Variations Within Species and Grades: Wood varies greatly in weight and strength. Young trees of moderate to rapid growth have reddish heartwood and are called red fir. The narrow-ringed wood of old trees may be yellowish-brown and is known as yellow fir.

Properties

Hardness/Janka: 660; 49% softer than Northern red oak. 
Dimensional Stability: Above average (change coefficient .00267; 28% more stable than red oak). 
Durability: Durable but easily dented. Somewhat brittle and splinters easily, especially with age. Used for flooring, but may not be suitable for all applications due to its softness.

Workability

Sawing/Machining: Harder to work with hand tools than the soft pines. 
Sanding: Sands satisfactorily.
Nailing: Good holding ability. 
Finishing: Some boards develop a slight pinkish to bright salmon color when finished with some products. Because of tendency toward color change, care must be taken to avoid oversanding when refinishing an existing floor. 
Comments: Sometimes milled for flooring as end-grain block, which is significantly harder than plainsawn.