Live Load
Variable, temporary loads from occupants, furniture, movable equipment, and environmental forces like snow. IRC standard is 40 psf for most floors.
In Detail
Live loads per IRC: floors 40 psf (habitable), sleeping areas 30 psf, decks 40 psf, attics (no storage) 10 psf. Roof live loads include snow, rain, and maintenance workers. Garages: 50 psf minimum. Live loads determine joist/rafter sizing via span tables.