Treated Pine vs Cedar vs Redwood

If you have ever stood in the lumber aisle doing mental math while staring at a stack of boards, welcome to the club. For outdoor projects, the “best” lumber is usually the one that matches your weather, your budget, and how much upkeep you are willing to do a year from now.

Let’s compare the big three you will see most often for backyard builds: pressure-treated pine (treated pine), cedar, and redwood. I will walk you through what each one does well, what it does not, and exactly where I use them on decks

Quick picks (if you just need an answer)

• Best budget deck framing: pressure-treated pine
• Best “nice looking” deck boards with lower upkeep: cedar (or redwood if available and affordable)
• Best pergola beams and posts: cedar or redwood for stability and looks, treated pine if you will paint and want to save money
• Best raised garden beds: cedar (my usual pick), redwood if you can get it, treated pine only if you are comfortable with modern treatment and you line the bed correctly

Now let’s earn those choices.

What kills outdoor wood

Outdoor lumber fails for a few predictable reasons:

• Rot and fungus: wood stays wet too long, especially where air cannot circulate
• Insects: termites and carpenter ants in some regions, plus general “bugs love damp wood” issues
• Movement: boards cup, twist, check, and split as they cycle between wet and dry
• UV damage: sun breaks down surface fibers, leading to graying and roughness
• Bad detailing: end grain touching soil, no drainage gaps, fasteners that corrode, or posts sitting in wet pockets

Species matters, but design and installation matter just as much. You can buy premium wood and still build a rot farm if you trap water.

Pressure-treated pine (treated pine)

What it is

This is usually Southern Yellow Pine that has been pressure-treated with preservatives so it can handle outdoor exposure. Today’s common residential treatments are copper-based (like ACQ, CA (copper azole), and MCA). You will see tags such as “ground contact” or “above ground,” and that label matters more than the shade of green on the board.

One important nuance: not all “treated” is equal. Treatment level and intended exposure are tied to Use Category ratings (often shown as UC3B for above-ground exterior, and UC4A to UC4C for ground-contact duty). The exact labeling varies by brand and yard, but the big idea is simple: match the rating to the job, not the vibe.

Pros

• Best value for structural strength: great for joists, beams, and posts
• Widely available: easy to match later for repairs
• Good rot resistance when rated correctly: especially ground-contact material where needed

Cons

• Movement and checking: it often comes wet, then shrinks and cracks as it dries
• Heavier: hauling 16-footers feels like a workout class you did not sign up for
• Hardware requirements: modern treatments are more corrosive to standard steel, so you need approved fasteners and connectors
• Not my favorite for “touch surfaces”: splinters and cracks can show up on deck boards and benches

Where treated pine shines

• Deck framing: joists, beams, rim boards, ledger (when flashed correctly)
• Near-grade structure: use ground-contact rated material for posts, and for any member that is close to soil or likely to stay damp
• Painted outdoor projects: pergolas, fences, rails when you plan to prime and paint

My treated pine rules of thumb

• Buy the straightest boards you can and sight down every one. Do not be shy.
• Pick the right rating for the exposure: above-ground for parts that can dry out, ground-contact for parts close to soil, masonry, or anywhere moisture lingers. When in doubt, read the tag and follow local code.
• Let it dry before staining unless you are using a product labeled for damp wood. If water beads on the surface, it is usually too wet to stain.
• Use the right hardware: hot-dipped galvanized fasteners (often ASTM A153) or stainless steel. In coastal or salt-air areas, stainless (commonly 305 or 316) is often the safer long-term bet. Match connectors and fasteners to the lumber treatment per the connector manufacturer.

Cedar

What it is

Most “cedar” at the store is Western Red Cedar. It has natural oils and extractives that make it more resistant to rot and insects than untreated pine, without chemical treatment.

Pros

• Naturally rot resistant: especially heartwood
• Lightweight and usually stable: it often stays straighter than wet treated pine as it seasons, although any wood can move depending on grain and grade
• Great to work with: cuts cleanly, holds detail, and smells like a woodworking shop should
• Comfortable underfoot: a good pick for deck boards and handrails

Cons

• Softer wood: dents and scratches more easily (kids, dogs, patio furniture, you name it)
• Color changes fast in sun: it will gray unless you maintain a UV-protective finish
• Cost: usually more than treated pine

Where cedar shines

• Deck boards and railings: especially if you like the natural look
• Pergolas and privacy screens: nice appearance and good stability
• Raised beds: a common DIY favorite because it is naturally durable

My note on cedar grades

Not all cedar is created equal. “Clear” and “heartwood” boards generally last longer and look better than knotty, sapwood-heavy boards. Knots are not evil, but they can loosen and split over time in harsh weather.

Redwood

What it is

Redwood is naturally rot resistant like cedar, with a reputation for durability and a rich color. Availability varies a lot by region, and in many areas it is a special order item.

Pros

• Excellent natural durability: especially heartwood
• Beautiful appearance: deep red tones that can age nicely with the right finish and maintenance
• Good stability: generally behaves well outdoors

Cons

• Price and availability: often the most expensive and hardest to source
• Softness: like cedar, it can dent
• Grade matters: “all heart” redwood lasts significantly longer than cheaper sapwood-heavy boards

Where redwood shines

• Showpiece decks and pergolas: when you want natural wood beauty and are willing to pay for it
• Raised beds: long-lasting without chemical treatment, especially with thicker boards

Decks: best wood by part

1) Framing (joists, beams, ledger)

Pick: pressure-treated pine. It is strong, economical, and designed for this job. Use the correct Use Category for the exposure, and do not skip flashing at the ledger. Wood does not fail because it is “bad wood” as often as it fails because water gets trapped.

Code note: deck rules vary by location. Before you buy a cartload of lumber, check your local building code for required species, grades, spans, and approved connectors.

2) Decking (the boards you walk on)

Pick: cedar or redwood if you want a natural-wood deck that is nicer underfoot and often more stable than wet treated boards. Treated decking can work, but expect more checking and splinters unless you select carefully and maintain it.

3) Posts near grade

Pick: ground-contact treated pine unless you are using a post base that keeps the post end fully above concrete and out of standing water. Most post rot starts right where moisture hangs out: close to the ground.

Fastener and hardware reminder

If you use treated pine anywhere, make sure your screws, nails, hangers, and post bases are rated for it. This is not a fun place to “use what I have in the garage.”

Pergolas: looks vs life

Pergolas are a funny mix of structure and furniture. You want it to stay straight, look good, and not turn into a wobbly sail in a windstorm.

• Best for a stained, natural look: cedar or redwood
• Best for paint: treated pine (let it dry, then prime and paint)
• Best for big spans: whichever species you choose, size matters more than species. Do not undersize beams.

Also, use proper post bases and structural connectors. A pergola is not the place for mystery screws and hope.

Raised beds: what I recommend

For raised beds, we are balancing rot resistance, cost, and your comfort level with treated lumber.

My usual pick: cedar

Cedar is naturally rot resistant, easy to work with, and readily available in many areas. Use thicker boards if you can (2x material lasts longer than 1x). Keep the bed off constantly wet ground if possible, and design for drainage.

Redwood: excellent if you can get it

Redwood can last a long time, especially heartwood grades. If it is affordable in your area, it is a premium choice.

Treated pine: possible, but be specific

Modern residential pressure-treated lumber is typically alkaline copper-based (not the older CCA used in most residential settings decades ago). Many university extension offices consider current residential PT acceptable for garden use, but comfort levels vary and local guidance is worth following.

If you choose treated wood for beds, I recommend:

• Using ground-contact rated boards (and in very wet climates or high-decay zones, recognize that “ground contact” can mean different UC levels like UC4A vs UC4B)
• Using a liner that does not trap water against the wood. A common approach is heavy landscape fabric on the soil side (to reduce soil contact while still letting the bed drain). If you use plastic, do it thoughtfully and keep drainage paths clear so you do not create a soggy sandwich.
• Keeping vegetables in quality soil and compost, and avoiding direct contact between produce and the wood

If you are building beds for kids, or you simply want maximum peace of mind, cedar is the easy “sleep well at night” pick.

Finishing and maintenance

Treated pine

• Will weather and crack as it dries: that is normal
• Finish options: let it dry, then stain or paint. Use a penetrating exterior stain for easiest upkeep.

Cedar

• Will gray quickly in sun: beautiful silver if you like that look
• Finish options: clear or tinted exterior stain with UV protection, reapplied as needed

Redwood

• Can hold color well when finished: results depend heavily on finish, exposure, and grade
• Finish options: penetrating stains are your friend, especially semi-transparent

No finish lasts forever. If you want the wood to stay “new-looking,” plan on a maintenance cycle. If you are okay with natural weathering, focus on good construction details and let the sun do its thing.

Cost and availability

Prices swing by region and season, but the pattern is usually consistent:

• Least expensive: treated pine
• Mid to higher: cedar
• Highest and most variable: redwood

If redwood is rare where you live, do not burn a weekend chasing it unless you truly want it for the look. Cedar is often the sweet spot for DIYers: durable, attractive, and not totally budget-breaking.

Climate and location notes

• Coastal or salt air: corrosion is the real villain. Lean toward stainless fasteners and connectors, and follow manufacturer compatibility guidance.
• Very wet climates: prioritize drainage, airflow, and the correct treated Use Category near grade.
• High termite regions: treated framing and smart detailing can matter more than the species on the receipt.

Safety and handling

• Wear a dust mask when cutting or sanding any wood. Outdoor lumber dust is still dust.
• Gloves help, especially with treated pine splinters.
• Do not burn scraps of pressure-treated lumber.
• Use the right blades and support long boards. Most “oops” cuts come from boards sagging or twisting during the cut.

Buying checklist

• Sight down the board for twist and crown
• Check end grain for deep cracks and splits
• Look for heartwood in cedar or redwood when possible
• Avoid boards with loose knots where structure matters
• Match ratings to use: above-ground vs ground-contact for treated lumber, and confirm Use Category tags when available

If you only remember one thing: buy straight boards. Straight boards make straight projects, and straight projects make you feel like you know what you are doing even when you are learning.

FAQ

Can I use treated pine for raised beds?

You can, and many people do, especially with modern residential copper-based treatments. If you prefer to avoid it, cedar and redwood are great natural alternatives. If you use treated lumber, choose the correct rating, consider a liner that does not trap water, and check local extension or health guidance if you want the most conservative answer.

Which lasts longer, cedar or treated pine?

Properly rated and installed treated pine can last a long time, especially for framing. Cedar can also last a long time above ground and is naturally resistant. The winner often comes down to exposure, detailing, and maintenance more than the species name.

Is cedar strong enough for a deck frame?

Cedar is not typically used for primary deck framing in most DIY builds. Pressure-treated lumber is the standard choice for joists and beams because of strength, cost, and code expectations.

Do I need to seal cedar or redwood?

You do not have to, but if you want to slow graying and surface wear, use an exterior stain with UV protection. If you like the weathered look, skip the finish and focus on good construction and airflow.

My bottom line

If you are building a deck, I like pressure-treated pine for the skeleton and cedar or redwood for the parts you see and touch. For pergolas, cedar or redwood looks great and often stays straighter, while treated pine makes sense for painted builds. For raised beds, cedar is my go-to because it is durable, easy, and keeps the “should I worry about this?” questions off your plate.

Pick the wood that fits your project, then build it like water is always trying to sneak in. Because it is.