Cedar vs Pressure-Treated Calculator

With proper maintenance: cedar 18-25 years depending on grade (STK 18, Select Knotty 22, Clear 25). PT 24-27 years branded (YellaWood 25, Wolmanized 27); generic PT ~18 years without warranty backing. Without maintenance: both drop sharply — cedar to ~12 years (silvers fast, splits/cups), PT to ~14 years (UV degrades chemistry + face checking). Both materials are fundamentally wood — UV is the enemy. The difference: cedar fails by silvering and surface checking; PT fails by chemistry leaching out and rot reaching untreated heartwood.

Pressure-treated, by a wide margin. Generic PT SYP runs $1.85/lf vs cedar STK at $4.50/lf (cedar is 2.4× more). Premium clear cedar at $8.50/lf is 4.6× more than generic PT. For a 200 sqft deck (~600 lf of boards including waste): generic PT $1,100, YellaWood $1,290, WRC Select Knotty $3,300, WRC Clear $5,100. Material premium for cedar over PT is $2,000-4,000 on a typical deck. Factor that against expected lifespan: PT delivers more sqft-years per dollar.

Yes — to keep its color and slow weathering. Without finish, cedar oxidizes to a soft gray within 12-18 months (no structural impact — pure aesthetics). To preserve the reddish-brown look, apply Penofin Cedar, Sikkens Cetol Log & Siding, or Cabot Australian Timber Oil yearly. Costs ~$0.55/sqft material DIY ($165 for a 300 sqft deck per year). Cedar fans either commit to yearly oiling or accept the gray patina. Note: cedar should never be painted — paint traps moisture against the wood and accelerates rot.

Only above the 6″ ground-contact zone, and even then it's discouraged for joists. IRC 2021 R317.1 mandates ground-contact-rated lumber (PT UC4A) for anything within 6″ of grade. Cedar is naturally decay-resistant (R317.3 lists it as durable) but cannot be ground-contact rated by AWPA — its natural oils don't penetrate deep enough for in-soil performance. Practical solution: use cedar BOARDS on PT JOISTS. The boards are above-grade visible elements; the PT structure handles ground contact and load. This is the most-recommended DIY approach for cedar decks.

Cedar is significantly less splintery than PT. Cedar's softer, straighter grain (Janka hardness ~350 for WRC, ~1,000 for SYP PT) means less surface fracturing under foot traffic. Cedar 9/10 vs PT 6/10 on splintering resistance. Kids + bare feet matter more than the spec sheet suggests — most barefoot-deck reviews favor cedar by 2-3 stars. PT improves significantly with yearly stain refresh (locks down surface fibers) — but cedar still wins on day-1 splinter risk.

Both have sustainability tradeoffs. Cedar: no chemical treatment (fully compostable end-of-life, no leaching) BUT mature-tree harvesting required (most WRC comes from BC/PNW old-growth or 2nd-growth ranges; FSC-certified options exist). PT: faster-growing SYP (sustainable plantation) BUT copper-based chemical treatment contains compounds that don't break down in soil + can't be safely burned. Cedar score 6-8/10 (depending on grade + sourcing); PT 4-5/10 (chemistry penalty). For LEED projects, cedar wins easily; for budget pragmatism, PT's plantation source matters.

Cedar is slightly cooler — about 4°F less surface temp than PT on a sunny 90°F day. The difference is small because both are wood (similar thermal mass), but cedar's lower density means slightly less radiant heat absorption. Compared to composite/PVC, both wood materials run cooler than dark composite (~15-20°F cooler than Trex Enhance dark colors). Light-stained PT or light cedar both perform close to identical for barefoot comfort.

Both want stainless steel — for different reasons. Cedar's tannin acids react with standard galvanized (causes black streaks down the boards within months). PT chemistry (especially ACQ-treated generic) is corrosive to galv (rusts through screws in 3-5 yrs). Recommended: stainless 305 or 316 (marine-grade) for screws, post bases, and hangers on cedar AND on ACQ-treated PT. For modern MCA-treated PT (YellaWood, Weather Shield), HDG G185 hot-dipped is acceptable — ASTM A153 spec. Joist hangers: Simpson Stainless or HDG ZMAX, matched to fastener type.

Pressure-treated wins on 25-yr TCO by $2,500-4,500 on a typical 200-300 sqft deck. The math: cedar's $2-4/lf material premium compounds with cedar's higher fastener cost ($1.85/sqft stainless required vs $0.95/sqft HDG OK for MCA PT) and higher cedar-railing cost ($38/lf vs $26/lf PT). Maintenance is similar over 25 yrs (both ~$0.45-0.75/sqft/yr). PT's lower upfront wins decisively for DIY budget builds. Cedar's TCO advantage only shows up if you value aesthetics + splintering enough to ignore the $3,000-5,000 premium.