Wood of the Month: Majestic Douglas Fir the Leader in Plywood By Jo-Ann Kaiser

Douglas fir is a cone-bearing softwood, meaning that it is not a "true" fir. True firs belong to the genus Abies. Douglas fir seedlings thrive in an open, sunny environment. Trees that spring up in a forest setting dominated by Douglas firs are likely to be hemlocks, which grow well in shady conditions.

World's Premier Industrial Tree
Donald Culross Peattie writes about Douglas fir in A Natural History of Western Trees. "When the immortal frigate Constitution first put to sea in 1798, they carried as masts three lofty white pines felled in the state of Maine. But when in 1925 these had to be removed, there was left not white pine in all the eastern states tall enough to replace those glorious sticks. From the Northwest came, instead, three towering shafts of Douglas fir, and these 'Old Ironsides' bears in her decks today, where she rides in honor at the dock of Boston Navy Yard.

"Thus has white pine fallen from first place among the timber trees of the continent; thus has Douglas fir (which no American had ever seen or heard of when the keel of the Constitution was being laid), risen to position of premier industrial tree of the world." Peattie contends that the "noble" species which took white pine's place "is quite as versatile in fulfilling a hundred vital uses and many fold as abundant."

Douglas fir is one of the most versatile of the domestic wood species, with uses that include plywood, heavy construction, studding, floor boards, roof trusses, floor and ceiling joists, beams, interior and exterior joinery, marine piling, mining timber and dock and harbor-building material.

Second-growth trees have been used to produce thousands and thousands of miles of railroad track ties. Whole trees were once used to make telegraph and telephone poles. Douglas fir slabs and waste are an excellent source of firewood. The wood was at one time used widely for cooperage to make vats and tanks to hold an array of liquids from beer and liquor to chemicals.

Statistics Don't Lie
The statistics on Douglas fir are very impressive. The tree ranks first in lumber production for all of North America. According to Peattie, Douglas fir accounts for one-fourth of all standing saw timber in the United States. In addition to being one of the most commercially valuable species, it is one of the largest trees in the world. It reaches impressive heights of 100 to 200 feet tall on average, with some growing to 300 feet and one a to a record 415 feet. It is not unheard of to see trunks 17 feet in diameter and clear of branches for 100 feet, though average widths are three to four feet. The lack of branches on the lower two-thirds of the tree means a high percentage of the sawn wood is free of knots. The trees are also very hardy and can live 500 to 1,000 years.

Carpenters' Favorite Grows Quickly
One of Douglas fir's attributes is its tremendous regenerative powers, meaning felled trees are soon replaced with new ones that mature quickly.

"They are fertile; they are vigorous; they are very fast growing," Peattie writes. "These inherent qualities are favored by the reliable and abundant rainfall and mild climate."

Douglas fir's physical characteristics have made it popular with carpenters and architects, Peattie says, since it "does not warp or pull its nails. Kiln-dried fir makes a beautifully figured, easily finished interior woodwork, both in vertical and flat grain."

Sharp Tools Recommended
In Know Your Woods, Albert Constantine Jr. says that Douglas fir wood's strength and weight vary considerably depending on the part of the country it comes from. Some of the wood can be harder to work than many other commercial softwoods. To combat this effect, experts recommend using sharp cutting tools to avoid raising the grain. Careful nailing is also recommended to prevent splitting. Wood is moderately durable but susceptible to insect attack.