JoistLedgerSpans, joists and footings straight from the code tables.

Decking for a 10 × 14 ft deck in ipe, straight layout

1 × 6 ipe boards
24× 16 ft
22 rows across 10 ft — 323 linear ft including 5% waste
Plan — boards across the joists10 ft14 ft22rows5.688″ repeatactual width + gap24 boards · 484 screws
Boards to buy24× 16 ft
Linear feet308 ft plus 5% waste323ft
Rows of decking10 ft ÷ 5.688″ repeat22rows
Board repeat5.5″ actual width + 0.1875″ gap — not the nominal size5.688in
Deck area10 × 14 ft140ft²
Joists crossedat 16″ o.c. over 14 ft11joists
Deck screwstwo per board-joist crossing — about 2 boxes of 350484screws
Layoutboards run perpendicular to the joists — least wastestraight
Butt joints16 ft boards cover the 14 ft run in one pieceNone needed
Deck width
10 ft
Deck length
14 ft
Board
ipe
Layout
straight
Joist spacing
16 in o.c.

Nominal width is not actual width

This is where board counts go wrong. A ipe board measures its real width, and with the gap it needs the repeat is 5.688″ — which is what actually decides the row count.

10 ft of deck at that repeat is 22 rows, and 24 boards once 5% waste for the straight layout is added.

Working from the nominal size undercounts by close to a tenth.

The gap is not optional in either direction

Treated lumber is sold wet and shrinks. Composite expands with heat. Gap too tight on composite and it buckles in July; gap too wide on wet treated lumber and by autumn you have gaps that swallow a phone.

Screws

484 — two at every board-joist crossing, across 11 joists. One screw per crossing lets the board cup and lift at the corner, and that is the single most common reason a deck looks tired after two summers.

Read the end grain

Lay boards bark-side up. A board cups away from its bark side, so bark-up sheds water off the crown rather than holding it in a trough.

Butt joints

Where the run exceeds a standard board length, stagger the joints so no two adjacent rows meet over the same joist — and double the joist under every joint. A butt joint on a single joist gives each board about ¾ inch of bearing, which is not enough for either board.

Notes

  • **Nominal width is not actual width.** A "1 ×" board measures 5.5″ across. With a 0.1875″ gap the repeat is 5.688″, which is what decides the row count — 22 rows here. Working from the nominal size undercounts by close to a tenth.
  • Very dense and very stable; pre-drill every fastener. The gap is not optional in either direction: too tight on composite and it buckles in July; too wide on wet treated lumber and you get gaps you can drop a phone through by autumn.
  • Straight layout, 5% waste — boards run perpendicular to the joists — least waste. This is the least wasteful way to lay a deck, and the fastest.
  • A 16 ft board covers the 14 ft run in one piece. Worth paying for: an unbroken board is stronger, drains better and looks like a deck rather than a repair.
  • Fasten with two screws at every board-joist crossing — 484 screws here. One screw lets the board cup and lift at the corner, and it is the single most common reason a deck looks tired after two summers.
  • Lay the boards bark-side up if you can read the end grain. A board cups away from the bark side, so bark-up sheds water off the crown instead of holding it in a trough.

Nearby sizes

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