11 Floor Joist Spacing and Layout

Imperial (US) sizing resources

Use these US span tables:
space joists either 12″, 16″ or 24″ oc

Sawn Lumber use:
American Wood Council (AWC)
https://awc.org/codes-standards/calculators-software/spancalc

Engineered Lumber use:
Forest Products Supply
http://www.fp-supply.com/st-louis-trusjoist-tji-i-joists.html

Metric sizing resources

Use these European span tables:
space joists either 400mm or 600mm oc

Sawn Lumber use:
only the typical thicknesses 47X?? and 63X??
Dead load per square metre (in kN/m²) supported by joists “More than 0.5 but not more than 1.25” Do not use “more than 0.25 but not more than 0.5″
C16 or C24 timber
https://www.timberbeamcalculator.co.uk/span-tables/floor-joists
or
http://nhbccampaigns.co.uk/landingpages/techzone/previous_versions/2011/Part6/section4/appendix.htm#64AT2

Engineered Lumber use:
Dead load per square metre gk = 0.75 kN/m2
Use “SJL 45” if possible avoid using “SJL 90”
span tables link
steico manufacturer’s website

Links: