Materials for a 14×20 deck

33 deck boards (20 ft)

for 280 sq ft: 30 rows of 5½ in boards with a ⅛ in gap, on 16 joists, with 10% extra.

For a 14×20 foot deck, the boards run along the 20 ft side and the joists span the 14 ft side.

Materials for a 14×20 deck

Deck area280 sq ft
Deck boards (5½ in × 20 ft)33
Linear feet of decking600 ft (+10% = 660 ft)
Joists at 16 in on center16 × 14 ft
Joists at 12 in on center21 × 14 ft
Rim joists2 × 20 ft
Deck screwsabout 960

Framing sizes (joist depth, beams, posts and footings) depend on spans and local code; check your building department’s deck guide before you build.

Change the numbers

Deck boards needed

33 boards

20 ft long, 5½ in wide (5/4 × 6 or 2 × 6), 30 rows across a 14 ft deck.

Deck area280 sq ft
Rows of boards30
Linear feet600 (about $1,056)
Joists16 at 14 ft
Deck screws960 (2 per board at each joist)

Other deck sizes

Questions

How many deck boards do I need for a 14×20 deck?
33 boards 20 ft long (5½ in wide), laid in 30 rows, including 10% extra.
How many joists for a 14×20 deck?
16 joists 14 ft long at 16 in on center, or 21 at 12 in on center.
How many screws for a 14×20 deck?
About 960 deck screws: two per board at each joist. A 5 lb box holds roughly 350 to 450 screws.
How much does a 14×20 deck cost?
Decking boards alone run about $1,056 in pressure-treated pine or $2,640 in composite. A finished 280 sq ft deck built by a contractor typically costs $8,400 to $16,800.

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