PSF (Pounds per Square Foot)
Unit of pressure or load measurement used in structural engineering. Floors, roofs, and decks are rated for specific psf loads (e.g., 40 psf live load for residential floors).
In Detail
PSF is the standard unit for distributed loads in residential construction. Common values: residential floors 40 psf live + 10 psf dead, sleeping areas 30 psf live, decks 40 psf live, roofs 20–30 psf live (snow dependent), garages 50 psf live. Multiply psf by tributary area to get point loads at connections.