The Complete Guide to Cedar Wood: Types, Grades, Sizes, and What to Know Before You Buy
Cedar has been a favorite building wood for generations, and for good reason. It looks beautiful, smells great, and resists rot and insects without any chemical treatment. But cedar is not just one thing. There are several species, a range of grades, and a set of sizes that can trip you up if you do not know the basics before you shop.
This guide breaks it all down in plain terms. You will learn the main types of cedar, how grading works, how sizes are labeled, and the handful of things worth checking before you buy. By the end you will be able to walk into a lumberyard and order exactly what your project needs.
What Makes Cedar Wood Special?
Cedar stands out from other softwoods because of what nature built into it. The wood contains its own preservative oils that fight decay and repel insects, so it lasts outdoors far longer than untreated pine. It is also free of the pitch and resin found in many softwoods, which makes it one of the best woods for holding a stain or finish.
A few other traits make cedar a pleasure to work with:
- It stays put. Cedar is dimensionally stable, so it lies flat and resists the warping, cupping, and checking that plague other woods.
- It is lightweight. Cedar is easy to lift, cut, and fasten, which speeds up any build and makes it friendly for do-it-yourselfers.
- It looks and smells wonderful. The warm tones and soft grain suit any style, and the natural aroma is a bonus, especially with aromatic species.
- It is renewable. Cedar is a sustainable choice when it comes from responsibly managed forests.
One honest caveat: cedar is softwood. It is firm but resilient underfoot, not rock hard, so it can dent or scratch more easily than a dense tropical hardwood. For most homeowners that trade-off is well worth the beauty and easy handling.
The Main Types of Cedar Wood
Not all cedar is the same. The species you choose changes the color, the durability, the aroma, and the price. Here are the four you are most likely to run into.
Western Red Cedar
Western red cedar is the star of the group and the top pick for decks, siding, and outdoor projects. Native to the Pacific Northwest, it has warm reddish-brown tones, excellent natural durability, and the best dimensional stability of the bunch. If someone says cedar decking, they almost always mean western red cedar. It stains beautifully and resists decay and insects thanks to its natural oils.
Eastern Red Cedar (Aromatic)
Eastern red cedar, often called aromatic cedar, is the one with the strong, signature scent. That aroma comes from a high oil content that naturally repels moths and insects, which is why it lines closets and chests. It is lighter red with pale streaks and knots, and it is less durable and more knotty than western red cedar, so it is used more for closets, chests, fence posts, and landscape timbers than for smooth decking.
Eastern White Cedar (Northern White)
Eastern white cedar, also called northern white cedar, is a pale, light-tan wood common in the Northeast and Canada. It resists decay well and is a classic choice for shingles, shakes, and fencing. You will see it less often as decking, but it is a solid, rustic option.
Alaskan Yellow Cedar
Alaskan yellow cedar, or Alaska cedar, has a warm golden hue and is unusually strong and hard for a cedar. Its dense grain and natural oils make it very resistant to decay and moisture, so it shows up in decking, exterior trim, and even boatbuilding, especially in humid or coastal settings. It is a premium option and priced accordingly.
Understanding Cedar Grades
Grade is where cedar shopping gets confusing, because there are two grading systems and several agencies. Keep it simple by remembering the two purposes: appearance and structure.
Appearance grades, sometimes called select grades, apply to lumber under two inches thick where looks matter most. They use letters A through D, with A being the highest. Structural grades apply to thicker cedar, two inches and up, that carries weight. They use numbers 1 through 5, with 1 being the highest. Within appearance grades, the big choice is clear versus knotty.
| Grade | What it means | Best for |
|---|---|---|
| Architectural Clear | The top appearance grade, straight grain with few or no knots | Formal decks, premium siding, showpiece trim |
| Custom Clear / C and Better | High-quality clear wood with only minor characteristics | Quality projects on a smaller budget |
| Architect Knotty (Select Tight Knot) | Sound, tight knots with a smooth, skip-free face | Most cedar decks, rustic charm and value |
| Structural (No. 1 to No. 2) | Graded for strength, used at two inches thick and up | Joists, beams, posts, and framing |
For a deck surface, most homeowners land on Architect Knotty for its rustic look and friendly price, or a clear grade when they want a smooth, formal finish. There is no wrong answer, just a look and a budget.
Heartwood, Sapwood, and Grain
Two more terms shape how cedar performs. Heartwood is the darker wood from the center of the tree, and it holds the natural oils that resist rot. Sapwood is the lighter wood from the outer part of the trunk, and it is less durable. For anything near the ground or exposed to constant moisture, look for high heart content.
Grain direction matters too. Vertical grain, also called quarter sawn, is cut so the growth rings run straight across the board. It is the most stable and the most premium. Flat grain shows the wavy cathedral pattern and costs less, with a bit more movement over time. Both are beautiful, so this comes down to budget and the look you want.
Cedar Wood Sizes and How They Are Sold
Here is the detail that surprises first-time buyers: cedar is sold by nominal size, not by the actual measurement. A five-quarter, written 5/4, board is really one inch thick. A two-inch board is really an inch and a half. The nominal number is a label, not a ruler reading. The chart below shows the common sizes.
A few more sizing notes worth knowing:
- 5/4 x 6 is the classic decking board. It gives you a solid one-inch-thick walking surface at a good price, which is why it is the most popular cedar deck board.
- Surface matters. S4S means surfaced on four sides for a smooth finish. Rough sawn leaves a textured, rustic face. Pick based on the look and whether you plan to stain.
- Kiln-dried or green. Kiln-dried, or seasoned, cedar has been dried and is more stable. Green, or unseasoned, cedar still holds moisture and will shrink as it dries, so plan your spacing accordingly.
- Boards, planks, trim, and timbers. Beyond decking, cedar comes as siding boards, fascia, trim boards, railings, posts, and landscape timbers, so one material can tie a whole project together.
What Cedar Wood Is Used For
Cedar is one of the most versatile woods you can buy. The most common uses include decking and deck railings, exterior siding and trim, fences and gates, pergolas and arbors, raised garden beds and landscape timbers, outdoor furniture, and interior paneling and closet lining. Its blend of beauty, workability, and natural decay resistance makes it a fit almost anywhere indoors or out.
What to Know Before You Buy Cedar
Before you place an order, run through this short checklist so you get the right material the first time.
- Pick the grade for the job. Clear grades for a smooth, formal look, knotty grades for rustic charm and savings, structural grades for anything load-bearing.
- Check heart content for durability. For ground contact or wet areas, choose boards with more heartwood, which resists rot best.
- Decide kiln-dried or green. Kiln-dried is more stable and ready to finish. Green costs less but will shrink as it dries.
- Match the surface to your plan. Smooth S4S for a refined deck you will stain, rough sawn for a rustic, natural texture.
- Use the right fasteners. Cedar’s natural oils can react with regular steel and cause stains, so use stainless steel screws, and step up to a marine grade near salt air.
- Plan to seal it. Left bare, cedar weathers to a silvery gray. A quality finish preserves the warm color and extends its life. More on that in a dedicated care guide.
- Buy responsibly sourced wood. Cedar from well-managed forests is a renewable, eco-friendly choice, so ask about sourcing.
Pros and Cons of Cedar Wood
Every material has trade-offs. Here is the honest balance.
- Pros: Naturally resists rot and insects, dimensionally stable, lightweight and easy to work, stains beautifully, warm looks and pleasant aroma, and renewable when responsibly sourced.
- Cons: It is a softwood, so it dents and scratches more easily than hardwoods, it costs more than pressure-treated pine, and it needs periodic sealing to keep its color and reach its full lifespan.
Frequently Asked Questions
Is cedar a hardwood or a softwood?
Cedar is a softwood. It is firm but lighter and softer than dense hardwoods, which makes it easy to work but a bit more prone to dents and scratches.
What is the difference between red and white cedar?
Western red cedar is reddish-brown, very durable, and the top choice for decks and siding. Eastern red cedar is lighter, highly aromatic, and used more for closets and posts. White cedar is pale and common for shingles and fencing. For outdoor decks, western red cedar leads.
Is western red cedar the best cedar for a deck?
For most homeowners, yes. Western red cedar offers the best mix of durability, stability, appearance, and availability for decking. Alaskan yellow cedar is an even harder, premium option if your budget allows.
Does cedar wood need to be sealed?
Cedar will last outdoors untreated, but it fades to a silvery gray and lasts longer with care. A quality penetrating finish preserves the warm color, adds UV and moisture protection, and extends the wood’s service life.
How are cedar sizes measured?
Cedar is sold by nominal size, which is larger than the real board. A 5/4 board is actually one inch thick, and a 2 by 6 is actually one and a half by five and a half inches. Always plan around the actual net size.
The Bottom Line
Cedar earns its long-standing popularity. It is naturally durable, easy to work, beautiful, and renewable. The keys to buying well are simple: pick the species that fits your project, choose a grade that matches your look and budget, mind the difference between nominal and actual sizes, and plan to seal it. Get those right and cedar rewards you with a warm, long-lasting result.
If you are planning a cedar deck and want it built to last, the team known for affordable deck builder naperville area work can help you choose the right species and grade. Homeowners nearby can also reach an affordable deck builder in Barrington for a free consultation.