You need lumber for your construction project and have decided on cedar. You might think the buying process would be simple from now on: go to the building supply store and pick up some cedar, right? Not so fast, friend. Actually, there is more to cedar than you might imagine.

Western Red Cedar and Inland Red Cedar are two similar but not identical wood products on the market. So if you’re a cedar beginner, here’s a cedar 101 crash course for you.

1. Know your background

The scientific name for the western red cedar is Thuja plicata. It is a variety of softwood that grows in the western US and Canada, known for its extreme durability, natural preservatives, and of course, its natural beauty. The innate characteristics of Western Red Cedar make it ideal for premium cedar siding, decking, shake and shingles.

Even once you’ve decided that Thuja plicata is what you need for your construction project, there are still a few things you need to know. Most western red cedar comes from British Columbia, western Washington, and western Oregon. However, some western red cedars also grow inland. You’ll find it on the eastern slopes of the Rocky Mountains, in Idaho, Montana, as well as parts of Alberta and eastern British Columbia.

The cedars of the easternmost and higher elevation forests are still Thuja plicata, the same botanical species as the cedars growing to the west, but there are differences in the wood. In fact, the two varieties are sometimes processed, graded, and even labeled differently: wood from trees that grow in coastal forests as “Western Red Cedar,” wood from trees that grow further east as “Interior Red Cedar.” “.

Now that you know the background to these woodland wonders, here are things to consider when trying to determine which type to buy.

2. Take a closer look

Paul Mackie is the western area manager for the Western Red Cedar Lumber Association, but he also answers to “Mr. Cedar” for his ability to answer cedar questions.

Mackie said that while botanists may not make a scientific distinction between trees that grow inland and trees that grow on the coast, you will see a visual difference if you examine both types side by side.

“Inland fiber is different from coastal materials,” he said. “The fiber inside will be lighter, with a striped appearance, and the clear percentage is much lower.”

Cedar decking and siding specialists seeking the highest quality products source their Western Red Cedar from trees that grow in the coastal climate. These coastal trees are gigantic, growing up to 200 feet tall and over 10 feet in diameter. Its native habitat is anywhere from sea level to about 4,000 to 5,000 feet in elevation, and in warmer, wetter conditions than the cedars that grow on the other side of the mountains. They also offer a more diverse appearance.

“In the coastal fiber, you’ll see a wide range of colors in the tree,” Mackie said. “You’ll have everything from a dark chocolate to a light straw color, and all of those colors can occur within the same piece.”

3. Does size matter?

Larger coastal cedars also tend to have a higher percentage of “clear” grade material than better quality cedar siding, cedar shakes, and large beams. In regions of higher elevation and drier climate, Inland Red Cedar just doesn’t grow as big. If you need large diameter lumber or beams, it will need to come from Western Red Cedar that was grown in the coastal forests.

Smaller inland trees are better suited for different products than coastal trees, Mackie said. Split rail fencing or smaller pieces of wood are two common uses for interior red cedar.

“There’s not such a wide product range for inland cedar,” Mackie said.

4. Making the grade

The two types of cedar are also processed and graded differently. Cedar is generally classified into “clear” and “knotty” grades. “Clear” is the most visually perfect wood, while “knotty” is what it appears to be: it is quality wood that is structurally sound, but has some knots or other visual blemishes. Within the “clean” designation, wood is graded A through D, with “A and better clears” being the highest grade and “D” the lowest.

According to Mackie, Inland Red Cedar has a lower percentage of light wood, so small that most Inland Red Cedar producers don’t even sell grade A materials. “D and better light” is usually the highest grade available for Inland Red Cedar. It is still quality wood, but it is not as free of knots and stains as the “A” or better. Western red cedar growers have enough volume to offer a wide range of light grades, up to the highest upright-grain lightheart grades.

Also, two different pieces of wood might be labeled similarly even though they were actually graded by different standards. According to Mackie, different lumber producers grade according to different rules. Growers of western red cedar grown in coastal regions grade to cedar-specific rules, inland plants do not.

“A lot of the coastal mills just process cedar,” Mackie said. “Inland mills might make a run of ponderosa pine, then white pine, then cedar.”

Because cedar is just one of many products offered by inland sawmills, they do not abide by cedar-specific rules. Mackie said that in “knotty” grades, inland cedar is often graded according to Ponderosa pine grading rules. It all depends on where the wood was sourced from and what set of standards that particular producer was using.

5. Make the choice

So just because two pieces of wood look like cedar, smell like cedar, and may even be botanical siblings, doesn’t mean they’re identical. If you’re looking for a smaller piece of cedar where durability matters but appearance isn’t as crucial, Inland Red Cedar might fit your needs. If you’re looking for a really big beam or lumber and need the highest quality cedar available, Western Red Cedar is your best choice.

Know your source, consider the needs of your project, and you’ll be sure to get the type of cedar that’s right for you.