The maximum decking span is 16" on center with deck boards at 90 degrees of the joist.

For conventional designs with proper support systems 12" is recommended.

Property	5/4 Board	2x6 Board	4x4 Board
Flex Modulus (psi)** 1% Secant (4-point)	182,800	162,400	153,200
Flex Strength (psi) at 3% Strain (4-point)	3,110	2,810	2,700
Flex Modulus (psi)** 1% Secant	249,400	222,800	215,900
Compressive Modulus (psi)*** 1% Secant	n/a	n/a	95,700
Compressive Strength (psi) at 3% strain	n/a	n/a	1,960
Compressive Modulus (psi)*** Tangent	n/a	n/a	99,100
Specific Gravity (sp gr 23/23'C)	0.86	0.83	0.78
Thermal Expansion (in/in'C) (in/in'F)	1.1 E-4 0.60 E-4	1.0 E-4 0.56 E-4	1.2 E-4 0.65 E-4
Srew pull out (lbs.)	See Link	See Link	See Link
Nail pull out (lbs.)	See Link	See Link	See Link

Flexural Measurements as per ASTM D6109
Specific Gravity Measurements as per ASTM D6111
Thermal Expansion Measurements as per ASTM D6341
Compressive Measurements as per ASTM D6108

** Please note that ASTM D6109 specifies that 1% secant modules be the reported value for flexural Modulus. It is all right to report both the secant and tangent Modulus vales providing that they are clearly identified.

*** Pleas note that the ASTM D6108 specifies that the 1% modulus be the reported value for compressive modulus when no Hookean region exists. It is all right to report both the secant and tangent modulus values providing that they are cleared identified.