Cedar vs Pressure-Treated Lumber: Weight and Durability

I Grabbed the Wrong Board and My Back Knew It

So I was on a deck job last summer — mid-July, humid as all hell — and I reached for what I thought was a cedar 2x6. Nope. Pressure-treated southern yellow pine. My shoulder reminded me of the difference before my eyes did. And honestly, that moment kind of summed up the whole cedar vs pressure-treated debate for me: they look vaguely similar when they're fresh, but they are fundamentally different materials with different weights, different lifespans, and different costs.

I've been building with both for years and I still catch myself re-checking numbers, because the weight difference matters more than people think — especially when you're loading a trailer or calculating dead loads on a structure. If you're trying to figure out how much lumber you actually need (and how much it's going to weigh), our

will save you a headache.

Weight: The Numbers Nobody Memorizes

Here's the thing about lumber weight — it's not just about the species. It's about moisture content. A freshly treated board from the lumberyard is going to be soaking wet, sometimes dripping, and that water adds real pounds. Cedar, on the other hand, tends to come to you closer to its equilibrium moisture content, which means it's lighter right out of the gate and it stays lighter.

I put together a comparison table because I got tired of Googling this every time:

Lumber Type	Dry Density (lbs/ft³)	Green/Wet Weight per Board Foot (lbs)	Approx. Weight of 8ft 2x6
Western Red Cedar	~23	~2.0	~16 lbs
Pressure-Treated SYP (kiln-dried after treatment)	~36	~3.5	~26 lbs
Pressure-Treated SYP (wet from yard)	~45+	~4.5	~35 lbs
Incense Cedar	~25	~2.2	~18 lbs
Pressure-Treated Hem-Fir	~28	~2.8	~22 lbs

That wet pressure-treated SYP number is not a typo. I've weighed these boards on job sites. A single wet 2x12x16 can push past 80 pounds, and when you're carrying twenty of them up to a second-story deck frame, you feel every single one.

If you're doing a

for a materials order, keep in mind that the delivered weight of pressure-treated lumber could be nearly double what cedar weighs. That matters for delivery costs, trailer capacity, and honestly just how wrecked your crew is by lunch.

So for a pressure-treated 2x6x12 that's still wet:

Board feet = (2 × 6 × 12) ÷ 12 = 12 board feet
Weight ≈ 12 × 4.5 = about 54 lbs, give or take.

Same board in cedar? More like 24 lbs. That's less than half!

Durability: Where It Gets Complicated

Everyone assumes pressure-treated wins the durability contest. And in a lot of scenarios, yeah, it does — but the answer is messier than that.

Pressure-treated lumber gets its rot resistance from chemical preservatives (usually some copper-based formula like ACQ or CA-C) forced deep into the wood fibers. It's engineered to resist decay and insects, and for ground contact applications, it's basically your only realistic option. Cedar's natural resistance comes from oils in the heartwood — thujaplicins, if you want to get nerdy about it — and those oils do a genuinely impressive job at repelling insects and slowing rot. But they're not infinite.

Here's where I've seen the real-world differences play out:

Cedar decking that's left unfinished and exposed to standing water will start showing soft spots in maybe 8-12 years. I've torn out cedar decks that were 15 years old and the boards in shaded, damp areas were basically sponge. But the boards in sunny, well-ventilated spots? Still solid. Meanwhile, pressure-treated decking from the same era was holding up structurally but looked absolutely terrible — gray, splintery, with checking (those cracks that run along the grain) everywhere.

The takeaway I keep coming back to: pressure-treated is more durable in the worst conditions, but cedar ages more gracefully in moderate conditions. And if you're sealing or staining either one regularly (which you should be), the gap narrows a lot.

For structural framing — joists, beams, posts — I almost always spec pressure-treated. It's stronger, it handles ground contact, and the weight penalty doesn't matter as much when the lumber is staying put. For decking boards, railings, and fence pickets, cedar is lighter, easier to work with, and looks better without paint. You can use our

to compare material costs side by side, because that's the other half of this equation.

Quick Decision Guide

I'm not going to pretend there's one right answer. But after building probably 40+ decks and more fences than I can count, here's my general framework:

Use pressure-treated when: the wood touches or is near the ground, it's structural (joists, ledger boards, posts), you're on a tight budget, or you're in a region with serious termite pressure.

Use cedar when: appearance matters, you want a lighter material to work with, the application is above-grade and well-ventilated, or you're sensitive to the chemicals in treated wood (some people are, and I get it).

Use both when: you're smart. Seriously — a pressure-treated frame with cedar decking and railings is the move on probably 80% of residential deck projects. You get the structural reliability where it counts and the aesthetics where people actually see and touch the wood.

If you're trying to estimate how much material you need for a project like this, the

handles the surface boards while the

can help you ballpark the whole thing. And for figuring out joist spacing and spans, check the

— it works for deck framing too.

One more thing I'll mention: if you're hauling materials yourself, use the

before you load up. I've seen a half-ton truck squatting on its bump stops because someone didn't account for how heavy wet treated 6x6 posts are. It's not a good look (and it's not great for your truck either).

Does pressure-treated lumber weigh more than cedar?

Yes, significantly. Pressure-treated southern yellow pine weighs roughly 50-100% more than western red cedar, depending on moisture content. A wet PT 2x6x8 can weigh about 35 lbs versus around 16 lbs for the same board in cedar. Even after the treated wood dries, it's still considerably heavier because southern yellow pine is just a denser species.

How long does cedar last compared to pressure-treated wood?

It depends on the conditions. In ground contact or constant moisture, pressure-treated can last 20-40 years while cedar might only go 10-15. Above grade with good airflow and regular sealing? Cedar can last 20+ years and honestly look better doing it. The chemicals in PT lumber give it an edge in harsh environments, but cedar's natural oils are no joke either.

Can I mix cedar and pressure-treated on the same project?

Absolutely — and most experienced builders do exactly that. PT for the structure, cedar for the visible surfaces. Just make sure any fasteners you use are compatible with both (stainless steel or coated screws rated for ACQ-treated lumber).