Introduction
Pressure-treated lumber costs more than untreated framing lumber — typically 30–60% more per board — and that premium is only the start of the project budget. Fasteners must be hot-dip galvanized or stainless, ground-contact members carry higher-rated (pricier) stock, and delivery, stain, and hardware add up fast. A realistic budget prices all of it.
The Pressure Treated Lumber Calculator gives you the quantities; this guide turns quantities into money. Below are typical US planning price ranges for common PT sizes, a full material breakdown for a 12 × 16 ft deck, the cost drivers that move your number, and the hidden costs first-time builders miss. Prices below are planning ranges — lumber markets move by region and season, so treat every figure as a starting point to verify locally.
PT vs. Untreated: The Price Premium
The treatment process — pressure-impregnating preservative deep into the wood — adds cost at the mill, and the market prices it accordingly. As a rough planning rule, expect PT equivalents to run about one-third to three-fifths above untreated SPF framing in the same size. The premium is smallest on commodity 2×4s and largest on wide, long, or ground-contact-rated stock, where fewer mills compete.
The premium buys service life: a ground-contact UC4A post can last 20–40 years in soil where an untreated post might fail in 3–7. For anything outdoors, the comparison that matters isn’t board price — it’s cost per year of service, where treated lumber wins by a wide margin. The material guide explains which ratings deliver that lifespan.
Typical Planning Prices by Size
Representative US retail ranges for common PT stock (southern yellow pine, standard #2 grade, 2026 market — verify locally):
| Size | Typical range (USD) | Common use |
|---|---|---|
| 2×4×8 | $5 – $9 | Fence rails, framing |
| 2×6×8 | $8 – $14 | Deck joists (short spans) |
| 2×8×12 | $14 – $24 | Deck joists, beams |
| 2×10×16 | $28 – $45 | Beams, long joists |
| 4×4×8 post (UC4A) | $12 – $22 | Fence and deck posts |
| 6×6×8 post (UC4A) | $28 – $55 | Deck and pergola posts |
| 5/4×6×12 decking | $12 – $22 | Deck surface boards |
| 1×6×6 picket | $3.50 – $6.50 | Fence pickets |
Kiln-dried-after-treatment (KDAT) stock typically adds 15–30% over wet-treated equivalents — worth it for visible decking where straightness matters. For the full worked takeoff behind a deck budget, see the estimating guide.
Project Breakdown: 12 × 16 ft Deck Materials
A ground-level 12 × 16 ft (3.66 × 4.88 m) deck — 192 sq ft (17.8 m²) — using mid-range pricing and the piece counts from the worked example (38 decking boards, 15 joists, 3 rims, 3 beam boards, 3 posts, 1 ledger, 6 concrete bags, hardware):
| Item | Qty | Est. cost |
|---|---|---|
| 5/4×6×12 decking @ ~$17 | 38 | $646 |
| 2×8×12 joists @ ~$19 | 15 | $285 |
| 2×8×16 rim joists @ ~$24 | 3 | $72 |
| 2×10×16 beam boards @ ~$32 | 3 | $96 |
| 6×6×8 posts (UC4A) @ ~$42 | 3 | $126 |
| 2×8×16 ledger @ ~$24 | 1 | $24 |
| Concrete, 50-lb bags @ ~$6 | 6 | $36 |
| Fasteners, connectors, flashing | lot | $180 |
Materials subtotal: ~$1,465, or about $7.60 per sq ft ($82 per m²). Add stain/sealer (~$120) for a DIY all-in near $1,585. A contractor building the same deck typically charges $15–$35 per sq ft installed ($160–$375 per m²) depending on region, height, and finishes — $2,880 to $6,720 for this deck — so DIY saves roughly half if you own the tools. The DIY vs. pro guide breaks down that decision.
Project Breakdown: 100 ft Privacy Fence
A 100 ft (30.5 m) run of 6 ft cedar-style PT privacy fence — 14 UC4A posts, 26 rails, 241 pickets (with waste), concrete, and galvanized screws — lands near $1,850–$1,950 in materials at mid-range pricing, or about $19 per linear foot ($62 per meter). Installed by a fence contractor, the same fence typically runs $30–$60 per linear foot ($100–$200 per meter). An illustrated line-item version of this fence is worked through in the case study.
What Moves Your Number
- Region and season. Prices vary 20–40% between markets and spike in spring building season; get quotes in late fall or winter when you can.
- UC rating. UC4A ground-contact posts cost more than UC3B framing in the same size — spec the rating per member, not one rating for everything.
- Length. Long boards (16 ft+) carry a premium per linear foot over 8-footers; design spans to use common lengths.
- KDAT vs. wet. Kiln-dried-after-treatment adds 15–30% but cuts cull waste on visible work.
- Hardware. Stainless screws cost 2–3× hot-dip galvanized; structural connectors and post bases add $100–$300 to a deck.
- Delivery. $50–$100+ per load — or free over a minimum order; plan one consolidated delivery.
Hidden Costs First-Timers Miss
- Stain and sealer. $40–$60 per gallon covering ~200 sq ft (18.6 m²) per coat — a 192 sq ft deck needs 2+ gallons for two coats.
- Cut-end preservative. $10–$15 per can; every field cut on treated lumber should be resealed.
- Concrete for posts. Two 50-lb bags per post at ~$6 each adds up on a long fence.
- Tool rental. A power auger ($75–$125/day) beats hand-digging 14 post holes.
- Permit fees. $100–$500 depending on jurisdiction — check before budgeting.
- Waste disposal. Offcuts of treated lumber can’t be burned; dump fees apply.
Related Guides
- Complete Guide — the full overview of PT lumber estimating.
- Estimating Guide — step-by-step takeoff with a worked deck example.
- Material Guide — ratings, treatments, and species that drive pricing.
- Case Study — an illustrated fence project with exact line-item costs.
- Pre-Order Checklist — verify quantities and pricing before you buy.
- FAQ — quick answers on PT lumber costs and estimating.
Get Your Number
Budget a PT lumber project in three passes: quantities from the Pressure Treated Lumber Calculator, unit prices from two or three local suppliers (never one), and the extras — hardware, concrete, stain, delivery, and permits — that turn a lumber list into a project cost. Price the UC rating each member actually needs rather than defaulting everything to the most expensive stock, and re-check prices the week you buy: lumber moves.
Disclaimer: All prices are typical US planning ranges for illustration only — actual costs vary widely by region, supplier, season, and market conditions. Verify current pricing locally, and consult a licensed professional for structural or code-related decisions.
