Materials for a 10×20 deck

25 deck boards (20 ft)

for 200 sq ft: 22 rows of 5½ in boards with a ⅛ in gap, on 16 joists, with 10% extra.

For a 10×20 foot deck, the boards run along the 20 ft side and the joists span the 10 ft side.

Materials for a 10×20 deck

Deck area200 sq ft
Deck boards (5½ in × 20 ft)25
Linear feet of decking440 ft (+10% = 484 ft)
Joists at 16 in on center16 × 10 ft
Joists at 12 in on center21 × 10 ft
Rim joists2 × 20 ft
Deck screwsabout 704

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

25 boards

20 ft long, 5½ in wide (5/4 × 6 or 2 × 6), 22 rows across a 10 ft deck.

Deck area200 sq ft
Rows of boards22
Linear feet440 (about $774)
Joists16 at 10 ft
Deck screws704 (2 per board at each joist)

Other deck sizes

Questions

How many deck boards do I need for a 10×20 deck?
25 boards 20 ft long (5½ in wide), laid in 22 rows, including 10% extra.
How many joists for a 10×20 deck?
16 joists 10 ft long at 16 in on center, or 21 at 12 in on center.
How many screws for a 10×20 deck?
About 704 deck screws: two per board at each joist. A 5 lb box holds roughly 350 to 450 screws.
How much does a 10×20 deck cost?
Decking boards alone run about $774 in pressure-treated pine or $1,936 in composite. A finished 200 sq ft deck built by a contractor typically costs $6,000 to $12,000.

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