Is Douglas Fir a Hardwood Or A Softwood?

In a previous article, we asked the question of whether something that was hard can also be soft.  In this article, we ask in the reverse:  can something that is soft also be hard? 

We’re talking wood here, and we know there are hardwoods and softwoods, so the questions may not be that odd.

Hardwoods and Softwoods

We’ve written about hardwoods and softwoods quite often and have run through a number of woods common to home woodworking shops.  We’ve discussed elm, hickory, birch, spruce, and so many more.  We’ll run through just the basics of what distinguishes hardwoods from softwoods as we work toward the answer to that question.

The distinction between a hardwood and a softwood has nothing to do with the hardness or softness, although there is a difference.  Rather, it has to do with the type of tree from which the wood comes.  

• Hardwoods come from deciduous trees, trees that lose their leaves in the fall and winter and replace them with new leaves in the spring and summer.  Hardwoods produce flowers and fruit/nuts and include such trees as oak, maple, walnut, and alder.  
• Softwoods come from evergreen trees and are conifers.  They produce needles rather than leaves, and they produce cones (thus the name conifer).  The list of softwoods includes pine, spruce, and cedar.  
• Angiosperm and gymnosperm – angiosperm refers to hardwoods with their seeds encased in fruit or nuts; gymnosperm refers to softwoods where the seeds are exposed in cones.  This is a simplified explanation but an accurate one you may come across someday.

While there is more that distinguishes these trees from one another, including how water is distributed throughout them, this is sufficient for the purpose of this article.  

Douglas Fir Wood

Douglas fir, genus Pseudotsuga, the genus of around 6 species of evergreen trees, is native to western North America and eastern Asia.  Although a softwood, it is actually a very strong wood due to the nature of its straight grain and dimensional stability. The wood is a light brown color that gets darker with age.

It is a softwood, and some measure of care must be taken when milling and handling Douglas fir wood.  It is the highest-scoring softwood in North America in its stiffness and strength-to-weight ratio.  Its heartwood, coming from the center of the tree, is particularly rot-resistant, also.  

It is an ideal wood in home and building construction and is favored, especially in the construction of log cabins, as well as interior and exterior use.  Early 20th-century home construction in the American northwest favored Douglas Fir wood for flooring, and over 100 years later, those floors have retained their original quality.  

While Douglas fir wood is not necessarily easy to work with and can dull a cutting blade, once cut and sized and used in the chosen manner (we’ll get to its common uses in a moment), its straight grain provides strength parallel to its grain, as well as shear and compressive strength.

Douglas fir also presents some elastic qualities in that it will bend and yet return to its original shape, unlike many hardwoods – its bending strength is a notable strength of this wood.  It is susceptible to dings and scratches, so some additional measure of care is required when it is used as flooring.  Frequent sweeping/vacuuming to remove any sand/stones/dirt that could act as an abrasive when walked upon can keep the flooring free from those scratches.

Douglas fir is a relatively durable wood, also.  It has an inherent aversion to fungal decay, and as mentioned, its heartwood tends to be rot-resistant.  Its life expectancy in most uses is at least 35 years, although those floors in many Pacific Northwest century-old homes would suggest it is much longer.  

Douglas Fir and Janka Scale

The Janka Scale, developed by Gabriel Janka, measures the hardness of a wood.  The test involves a half-inch steel ball and the amount of pressure required to embed it halfway into a wood.  The Douglas Fir Janka rating is 660, and as hardness ratings go, this puts it in the middle of softwood ratings, higher than larch (590), chestnut (550), and hemlock (510), but softer than Southern Yellow Pine (690).

Hardness ratings, though, are only a part of the story about Douglas fir, as we have mentioned.

Douglas Fir – A Popular Christmas Tree Choice

Douglas fir is a common, popular, and top-selling tree at Christmas time.  Its sweet evergreen scent is favored in the house during the holidays.

Even beyond the evergreen scent, Douglas fir trees also have a taste, and the taste varies from species to species.  Those flavors include:

• Meyer lemon or tangerine peel
• Peach skin
• Sharp resinous green 

It won’t show up on your dinner table, but the differences in flavor of the Douglas fir is clear and real.  It will stay fresh and last 3-4 weeks in water and holds its needles well.  It’s not as sturdy as a Noble or Fraser fir tree, also used as Christmas trees, but is at least as popular.

Douglas Fir Resinous Odor

Speaking of resinous green flavor, Douglas fir does have a prominent resinous odor when working with it.  That odor might irritate breathing, so it is a good idea to keep the room well-ventilated and the air circulating to remove the odor.  It’s not toxic, but some might find it a little noxious.

Uses For Douglas Fir

Woodworkers consider Douglas fir to be a high-quality wood that has a wide variety of good uses.  This versatile wood, as we have mentioned already, is a common and popular softwoods choice for flooring, far more so than pine.  It has a high structural integrity that comes from its long and straight fibers and straight grains with high parallel strength. 

Among its other wide range of uses:

Trim.  Moldings, window sills, baseboards, window casings, door casings, and more.

Furniture.  While we’re more accustomed to working with oak, walnut, or maple for our furniture projects, Douglas fir is a very good choice as well.  It’s a sturdy wood that stands up well in all furniture projects and is robust, almost on par with some hardwoods.  It finishes well and is a beautiful wood when handled properly.

Boats.  Yes, although a softwood, Douglas fir was and is used in boat building.  Its strength against bending or buckling is its advantage in building boats.  Douglas fir was used in making some of the smaller boats for the US Navy – patrol boats, minesweepers, for instance – during 
WW II.  

Airplanes.  The dimensional stability of Douglas fir makes it a good choice in the building of small airplanes.  The wood is not affected by changes in the environment – expanding in warmth, contracting in cold – and this makes it well-suited for small-plane construction.  Early military planes used Douglas fir in their construction – biplanes, and tri-planes of WW I.

Douglas Fir in Video

Sit back and relax as you watch a couple of serious woodworkers using Douglas fir to build a custom desktop.  The wood is reclaimed, and these fellows break it down to size.  Along the way, though, they discuss the importance of grain in assembling a desktop, something we have not spoken of often on these pages.

Wouldn’t you love to have some of the space and the equipment those fellows have? Be sure to watch it to completion to see the finished project and the cool adjustable height system the desk was fitted with for both stand-up and sit-down use.

Keep Doug-fir, as it is referred to in shorthand, is an interesting wood to work within the home woodworking shop as well as for construction projects.  If you haven’t worked with it before, consider it for your next furniture, trim, or flooring project.  It will serve you well.