DeckMath
Maine · 20×12 (240 sqft) · 2026-Q1 retail

20×12 Deck Cost in Maine

A 20×12 (240 sqft) deck in Maine costs $14,640-$23,520 in mid-tier composite with the state's 1.22× labor multiplier (Northeast). A 12×20 deck (240 sqft) is a long, narrow deck — common for ranch-style homes with a long back wall. Maine's frost depth is the deepest in the contiguous US — footings can run 5-7 ft deep. Labor 1.22× national.

240 sqft1.22× laborFrost 60snow climate64 lf perimeter
Area
240 sqft
20×12
PT pine (budget)
$7,440-11,760
$31-49/sqft installed
Mid composite
$14,640-23,520
$61-98/sqft installed
Luxury PVC
$22,080-32,160
$92-134/sqft installed

5 finish tiers — 20×12 in Maine

National $/sqft × Maine's 1.22× labor multiplier × 240 sqft = total installed cost. Materials + labor + standard railing included.

Tier
$/sqft
Total low
Total high
Budget · Pressure-treated
PT pine
$31-$49
$7,440
$11,760
Mid · Cedar / premium PT
Cedar
$43-$67
$10,320
$16,080
Premium · Mid composite
Trex Transcend, Fiberon Sanctuary
$61-$98
$14,640
$23,520
Luxury · Premium composite
TimberTech AZEK, Trex Signature
$92-$134
$22,080
$32,160
Exotic · Tropical hardwood
IPE, Cumaru
$110-$171
$26,400
$41,040

Excludes permit ($240-$592 typical in Maine), demolition (if replacing), and exceptional framing for 60″ frost depth. ME permits $200-350. Frost depth 60″ in northern Maine.

20×12 framing notes for Maine

Joist size
2×10 @ 16″ OC
Span 20 ft requires 2×10 SYP or PT pine for IRC R507.6 compliance. Check Joist Span Calculator for exact spans by species + spacing.
Beam configuration
2-3 beams
A 20×12 deck typically needs 2-3 beams depending on whether you can drop joists onto the beam (1) or hang them flush (2+).
Post count
6 posts
6×6 PT posts at 6-post layout typical. Footings extend below 60″ frost line.
Footings
6 × 60″ deep
Sonotube 10-12″ diameter at 60″ depth per IRC R403.1.4. Concrete budget: ~$329.
Decking
396 lf
240 sqft × 1.65 lf/sqft = 396 lf of deck boards at 16″ joist OC. Add 5-7% waste for cuts.
Railing
64 lf perimeter
64 lf of railing (~$36/lf mid composite, ~$22/lf wood). Stairs need 2 extra handrails (1 each side).

Maine considerations

Labor multiplier
1.22×
Northeast region labor pricing on all installed costs.
Frost depth
60″
Footings extend below frost line per IRC R403.1.4. Deep frost — sonotube + concrete dominates foundation budget.
Climate
snow
Freeze-thaw cycles favor PVC over composite where budget allows.
Top metros
Portland · Bangor
Major metros drive installer availability + pricing pressure.
Permit fee
$240-$592
ME permits $200-350. Frost depth 60″ in northern Maine.
Region
Northeast
Northeast regional pricing applied. Multiply national $/sqft by 1.22× for Maine installed cost.

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FAQ — 20×12 deck in Maine

How much does a 20×12 deck cost in Maine?

In Maine, a 20×12 (240 sqft) deck costs $7,440-$11,760 in pressure-treated, $14,640-$23,520 in mid-range composite (Trex Transcend / Fiberon Sanctuary), and $22,080-$32,160 in luxury composite/PVC (TimberTech AZEK / Trex Signature). Numbers reflect Maine's 1.22× labor multiplier on 2026-Q1 retail.

What's the cheapest way to build a 20×12 deck in Maine?

Cheapest = ground-level pressure-treated pine with no railings (where exempt under 30″ height) — ~$5,856-$8,784 in Maine. Add stairs + railings + above-grade framing and the build goes to ~$8,198-$11,712. DIY saves 30-50% on labor but requires permit + inspection coordination yourself.

How long does it take to build a 20×12 deck in Maine?

Permit timeline in Maine: 2-6 weeks depending on jurisdiction. Construction time for a 20×12: 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 20×12 deck in Maine?

IRC R507-compliant framing for a 20×12 deck typically uses 2×8 joists at 16″ OC for spans up to 12 ft, 2×10 joists for spans 12-16 ft. Maine's frost depth is 60″ — footings must extend below that per IRC R403.1.4. Deep frost requires more concrete per footing — budget extra for sonotubes + concrete. Verify with your local building department.

Is composite worth it for a 20×12 deck in Maine?

Over 25 years in Maine: PT pine = ~$8,784 install + ~$18,300 maintenance (stain every 2-3 yr) = $27,084 total. Mid composite = ~$16,982 install + $0 maintenance = $16,982 total. Composite wins by 59-81% over 25-yr lifecycle PLUS better resale value in Maine's market.

Compare Maine brand pricing for a 20×12

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