Oak vs. Douglas Fir: Which One to Use?

Oak vs. Douglas Fir: Which One to Use?

Handyman's World is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to amazon.com.

If you are planning on doing some building around your house, there are few better options than solid wood. However, there are of course many different types of wood out there, with two very popular choices being oak and Douglas fir.

However, these two materials are quite different from each other, and these differences are what we are here to discuss today. Let’s do a side-by-side comparison to figure out which of these two types of wood is best for your next construction or woodworking project.

What Is Oak?

First, we have the oak tree. Today, we are focusing on the red oak tree, which is one of the most commonly found types in the North American continent. It is also one of the most popular for construction purposes.

However, there are over 160 types of oak trees around the world, particularly in Northern Africa, Northern Europe, North America, northern Asia, and all throughout the Northern Hemisphere.

The oak tree is a deciduous hardwood tree, and it is quite hard, heavy, dense, and structurally sound. It is physically durable and resistant to many types of physical damage, such as denting and scratching.

Although it does contain some natural oils and resins, it is not the best choice for outdoor use. If properly treated and sealed, it can be used outdoors for a limited period of time. However, if not properly sealed, it won’t last outdoors, especially not over the long run. This type of wood is also not very resistant to fungi or pests.

As for appearance, oak has a very straight and tight grain, combined with an uneven and coarse texture, and quite a few gaps and knots, along with a brownish-red color. This wood is often used for interior purposes, such as for flooring, cabinets, walls, furniture, decorative pieces, and other small projects.

What Is Douglas Fir

We then have the Douglas fir, which is a type of evergreen or coniferous tree that can be found all throughout western North America and Eastern Asia. Douglas fir is a softwood tree that can grow up to 250’ tall with trunks up to 6’ wide.

There are both Rocky Mountain and coastal types of Douglas fir, and both are part of the hemlock tree family. This material, although it is a softwood, is fairly hard and durable. Of course, when compared to types of hardwood, it is relatively soft, but for softwood, it holds up quite well.

At the same time, Douglas fir is also quite resistant to moisture and pests, which is why it is often used for outdoor purposes, and even for marine-related applications.

Douglas fir is often used for purposes such as flooring, exterior siding, structural beams, and everything in between. It has quite a straight and plain grain, a medium coarse texture, and lumber that is light brown in color with a reddish-orange hue.

Oak vs. Douglas Fir: What Are the Differences

Now that we know what both oak and Douglas fir are, let’s figure out what makes these two types of wood different from each other.

Hardness

In terms of hardness, Douglas fir features a Janka hardness rating of 620 lbf, while oak comes in at 1,220 lbf. This means that oak is effectively twice as hard, making it much better at resisting various forms of physical damage, particularly denting and scratching.

For this reason, oak makes for the better choice for things like indoor furniture and other pieces that have to be durable against physical damage.

Density

In terms of weight or density, Douglas fir weighs roughly 32 lbs per cubic foot, while oak weighs around 43 lbs per cubic foot.

As you can see, oak is significantly heavier than Douglas fir. This does in part lend to its increased durability and structural soundness. However, because it is heavier, it is also harder to work with.

Pest and Moisture Resistance

Something that needs to be said about oak is that it is not very moisture or pest-resistant. It is definitely not the number one choice for outdoor use. If it is properly sealed and treated, it may last for a couple of years outdoors, but it’s not recommended, especially not when compared to Douglas fir.

Douglas fir is very resistant to the elements, and it is so resistant to moisture and water that it is often used for marine-related purposes, such as dock and boat building. At the same time, it’s also very resistant to pests and is overall a very good type of wood to use outdoors.

Overall Strength

Other than pest and moisture resistance, Douglas fir is unfortunately not very hard or durable. When it comes to factors such as compressive strength, the modulus of elasticity, and the modulus of rupture, oak is the much stronger of the two.

Workability

In terms of how easy these types of wood are to work with, Douglas fir is going to be the easier of the two. The reason for this is that it is not as hard or dense, which means that saw blades, screws, and nails will have a much easier time penetrating the surface. Because it is lighter, there’s also not as much that you have to lift around. However, both do take on paint and stain fairly well.

Appearance – Color and Grain

Both of these types of wood have a fairly straight grain, although Douglas fir is a bit wavy at times. Furthermore, it is not quite as coarse as oak. At the same time, Douglas fir is a bit lighter brown with a slightly reddish hue, whereas oak is a bit darker reddish-brown. In terms of appearance, it really comes down to what your personal preferences are.

Cost

Red oak is going to cost you up to $25 per board foot, while Douglas fir is going to cost you up to $14 per board foot.

When to Use Oak?

If you need a type of wood that is extremely hard, durable, and structurally sound, then oak makes for a fantastic option. Due to its durability and hardness, it’s a good choice for anything that needs to bear weight, such as floors and beams, and it works really well for furniture as well, mainly because it is very resistant to denting and scratching. It also makes for an attractive material to use for decorative pieces.

When to Use Douglas Fir?

If you need a type of wood that is ideal for outdoor purposes, to the point where it could even be submerged for short periods of time, then Douglas fir is a great choice.

Douglas fit may not be the hardest, densest, or most structurally sound type of wood, although it can still be used for basic purposes. It is solid enough for basic construction uses, but it really excels at outdoor use, especially due to its resistance to the elements.

Alternatives to Oak and Douglas Fir

Although oak is quite hard and durable, there are harder and more durable options out there. These include, but are not limited to, mahogany, teak, sugar maple, ebony, ironwood, and others. If you are looking to make some indoor or outdoor furniture out of wood that is both hard and resistant to the elements, ebony and teak make for the best options.

Summary

What it really boils down to is that oak is the best choice for indoor purposes, whereas Douglas fir is better for outdoor use. Now that you know what makes these two types of wood different from each other, you can choose the one that works best for your next project.