20×16 Deck Cost in Alabama
A 20×16 (320 sqft) deck in Alabama costs $14,720-$23,680 in mid-tier composite with the state's 0.92× labor multiplier (South). A 16×20 deck (320 sqft) is the canonical 'mid-large' deck — fits a full sectional, a 6-seat dining table, and a grill island. Alabama labor runs ~0.92× national. Humid summers favor composite over PT, but mid-tier composite still beats PT on 25-yr TCO.
5 finish tiers — 20×16 in Alabama
National $/sqft × Alabama's 0.92× labor multiplier × 320 sqft = total installed cost. Materials + labor + standard railing included.
Excludes permit ($105-$259 typical in Alabama), demolition (if replacing), and exceptional framing for 6″ frost depth. Most AL jurisdictions require permits for decks > 30″ off grade or > 200 sqft. Fees typical $100-180.
20×16 framing notes for Alabama
Alabama considerations
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FAQ — 20×16 deck in Alabama
How much does a 20×16 deck cost in Alabama?▾
In Alabama, a 20×16 (320 sqft) deck costs $7,360-$11,840 in pressure-treated, $14,720-$23,680 in mid-range composite (Trex Transcend / Fiberon Sanctuary), and $22,080-$32,320 in luxury composite/PVC (TimberTech AZEK / Trex Signature). Numbers reflect Alabama's 0.92× labor multiplier on 2026-Q1 retail.
What's the cheapest way to build a 20×16 deck in Alabama?▾
Cheapest = ground-level pressure-treated pine with no railings (where exempt under 30″ height) — ~$5,888-$8,832 in Alabama. Add stairs + railings + above-grade framing and the build goes to ~$8,243-$11,776. DIY saves 30-50% on labor but requires permit + inspection coordination yourself.
How long does it take to build a 20×16 deck in Alabama?▾
Permit timeline in Alabama: 2-6 weeks depending on jurisdiction. Construction time for a 20×16: pro crew = 5-8 days for framing + boards + railings + stairs. DIY = 3-5 weekends for experienced DIYer. Allow extra time for permit approval + inspections.
What framing do I need for a 20×16 deck in Alabama?▾
IRC R507-compliant framing for a 20×16 deck typically uses 2×8 joists at 16″ OC for spans up to 12 ft, 2×10 joists for spans 12-16 ft. Alabama's frost depth is 6″ — footings must extend below that per IRC R403.1.4. Sonotube 10-12″ diameter at 6″ depth is typical. Verify with your local building department.
Is composite worth it for a 20×16 deck in Alabama?▾
Over 25 years in Alabama: PT pine = ~$8,832 install + ~$18,400 maintenance (stain every 2-3 yr) = $27,232 total. Mid composite = ~$17,075 install + $0 maintenance = $17,075 total. Composite wins by 59-81% over 25-yr lifecycle PLUS better resale value in Alabama's market.