Douglas Fir
Species Information
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 woods: 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.
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