Free tool
Deck Material & Cost Calculator
Size your deck and get board counts, joist and footing counts, and a Twin Cities installed price for pressure-treated, cedar or composite.
Free tool
Deck Material & Cost Calculator
| Deck area | 280 sq ft |
|---|---|
| Decking (5.5 in boards, 5% waste) | 644 linear ft |
| Joists at 16 in on center | 16 × 14 ft |
| FootingsBelow Twin Cities frost depth — required by code and by physics. | 8 at 42 in deep |
| Railing | 54 linear ft |
| Stairs | 4 risers |
| Guard heightRequired on any walking surface more than 30 in above grade. | 36 in minimum |
Installed cost, Twin Cities
$12,208 – $18,385
A ballpark, not a bid. Access, condition, permits and soil move the real number. Send it over and we'll price your actual project for free.
Footings are the whole ballgame in Minnesota
Deck footings here have to bear below frost — typically 42 inches or more in the metro — and they get inspected. Surface blocks and shallow piers work fine in Tennessee and fail in their second Minnesota winter, tilting the frame and pulling the ledger away from the house.
The ledger connection is the other failure point. Most collapsed residential decks come apart at the ledger, not the field. It needs proper structural fasteners, flashing that keeps water out of the rim joist, and it cannot be nailed on.
Composite versus wood over 20 years
Pressure-treated pine is the cheapest to build and the most expensive to own — figure staining or sealing every two to three years, and board replacement starting around year 12 in our freeze-thaw and UV cycle. Cedar looks better and ages more gracefully but still wants maintenance.
Composite runs 40 to 70 percent more up front and effectively zero maintenance beyond washing. On a deck you plan to keep past 12 years, the lifetime numbers usually favor composite. On a house you're selling in five, treated lumber is the rational choice.
Common questions
- How deep do deck footings need to be in Minnesota?
- At least 42 inches in most of the Twin Cities metro so the bearing surface is below frost. Your city's building department sets the exact figure and inspects the holes before the pour.
- Do I need a permit to build a deck?
- Almost always, yes. Metro cities generally require a building permit for any deck attached to the house or more than 30 inches above grade, along with a site plan and inspections at footing and framing.
- How much does a deck cost in the Twin Cities?
- Roughly $30 to $45 per square foot installed for pressure-treated, $40 to $60 for cedar, and $52 to $95 for composite and PVC, before stairs and upgraded railing.
- When do I need railing?
- Any walking surface more than 30 inches above grade needs a guard, typically 36 inches tall, with baluster spacing that won't pass a 4 inch sphere.