Calculate total linear feet, number of standard boards (8', 12', 16', 20'), joists, fasteners, and waste allowances for any wood or composite deck.
(22.3 sq meters) · 26 rows of boards
To calculate deck boards, divide the deck dimension by the effective board width (nominal width + gap) to find the number of rows. Then multiply rows by the run length to find total linear feet, add 10% for cutting waste, and divide by stock board length (e.g. 16 feet).
A 3/16" (0.188") gap is the industry standard for composite and kiln-dried wood decking to allow water drainage and expansion. For wet pressure-treated lumber, a 1/8" gap is typical as boards will naturally shrink after drying.
Standard construction requires 2 screws at every joist intersection. For 16" on-center joists, plan for approximately 350 screws per 100 square feet of deck surface.
Most composite decking manufacturers (like Trex, TimberTech) require 16" on-center joist spacing for straight boards, but require 12" on-center spacing when laying boards on a 45-degree diagonal pattern to prevent sagging.
