DeckMath
Montana · 10×8 (80 sqft) · 2026-Q1 retail

10×8 Deck Cost in Montana

A 10×8 (80 sqft) deck in Montana costs $5,120-$8,160 in mid-tier composite with the state's 1.28× labor multiplier (West). An 8×10 deck (80 sqft) is the smallest practical deck size — barely fits a 4-person bistro set. Most affordable build in this list. Montana labor 1.28× national. Frost depth among the deepest in the US — footing cost dominates.

80 sqft1.28× laborFrost 60snow climate36 lf perimeter
Area
80 sqft
10×8
PT pine (budget)
$2,560-4,080
$32-51/sqft installed
Mid composite
$5,120-8,160
$64-102/sqft installed
Luxury PVC
$7,680-11,280
$96-141/sqft installed

5 finish tiers — 10×8 in Montana

National $/sqft × Montana's 1.28× labor multiplier × 80 sqft = total installed cost. Materials + labor + standard railing included.

Tier
$/sqft
Total low
Total high
Budget · Pressure-treated
PT pine
$32-$51
$2,560
$4,080
Mid · Cedar / premium PT
Cedar
$45-$70
$3,600
$5,600
Premium · Mid composite
Trex Transcend, Fiberon Sanctuary
$64-$102
$5,120
$8,160
Luxury · Premium composite
TimberTech AZEK, Trex Signature
$96-$141
$7,680
$11,280
Exotic · Tropical hardwood
IPE, Cumaru
$115-$179
$9,200
$14,320

Excludes permit ($218-$537 typical in Montana), demolition (if replacing), and exceptional framing for 60″ frost depth. MT permits $150-280. Frost depth 60″ in northern MT.

10×8 framing notes for Montana

Joist size
2×8 @ 16″ OC
Span 10 ft requires 2×8 SYP at standard 16″ OC. Check Joist Span Calculator for exact spans by species + spacing.
Beam configuration
1-2 beams
A 10×8 deck typically needs 1-2 beams depending on whether you can drop joists onto the beam (1) or hang them flush (2+).
Post count
4 posts
6×6 PT posts at 4-post layout typical. Footings extend below 60″ frost line.
Footings
4 × 60″ deep
Sonotube 10-12″ diameter at 60″ depth per IRC R403.1.4. Concrete budget: ~$230.
Decking
132 lf
80 sqft × 1.65 lf/sqft = 132 lf of deck boards at 16″ joist OC. Add 5-7% waste for cuts.
Railing
36 lf perimeter
36 lf of railing (~$36/lf mid composite, ~$22/lf wood). Stairs need 2 extra handrails (1 each side).

Montana considerations

Labor multiplier
1.28×
West 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
Billings · Missoula · Bozeman
Major metros drive installer availability + pricing pressure.
Permit fee
$218-$537
MT permits $150-280. Frost depth 60″ in northern MT.
Region
West
West regional pricing applied. Multiply national $/sqft by 1.28× for Montana installed cost.

Get a precise quote for your 10×8 deck in Montana

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FAQ — 10×8 deck in Montana

How much does a 10×8 deck cost in Montana?

In Montana, a 10×8 (80 sqft) deck costs $2,560-$4,080 in pressure-treated, $5,120-$8,160 in mid-range composite (Trex Transcend / Fiberon Sanctuary), and $7,680-$11,280 in luxury composite/PVC (TimberTech AZEK / Trex Signature). Numbers reflect Montana's 1.28× labor multiplier on 2026-Q1 retail.

What's the cheapest way to build a 10×8 deck in Montana?

Cheapest = ground-level pressure-treated pine with no railings (where exempt under 30″ height) — ~$2,048-$3,072 in Montana. Add stairs + railings + above-grade framing and the build goes to ~$2,867-$4,096. DIY saves 30-50% on labor but requires permit + inspection coordination yourself.

How long does it take to build a 10×8 deck in Montana?

Permit timeline in Montana: 2-6 weeks depending on jurisdiction. Construction time for a 10×8: pro crew = 3-5 days for framing + boards + railings + stairs. DIY = 2-3 weekends for experienced DIYer. Allow extra time for permit approval + inspections.

What framing do I need for a 10×8 deck in Montana?

IRC R507-compliant framing for a 10×8 deck typically uses 2×8 joists at 16″ OC for spans up to 12 ft, 2×10 joists for spans 12-16 ft. Montana'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 10×8 deck in Montana?

Over 25 years in Montana: PT pine = ~$3,072 install + ~$6,400 maintenance (stain every 2-3 yr) = $9,472 total. Mid composite = ~$5,939 install + $0 maintenance = $5,939 total. Composite wins by 59-81% over 25-yr lifecycle PLUS better resale value in Montana's market.

Compare Montana brand pricing for a 10×8

Same 10×8 in other states