Span tables
Lumber span tables
Each table below is reproduced verbatim from a published, code-recognized source - the International Residential Code (IRC) span tables and the American Wood Council's DCA6 deck guide - with the exact edition and table number cited on every page.
New to these grids? How to read a span table walks through the five keys printed around every one of them - member and load case, live and dead load, deflection limit, species and grade, and spacing - and what L/360 deflection means explains the limit in each heading, and why the floor, ceiling and rafter tables do not share one.
40 psf · L/360
Floor Joists - 40 psf Live Load (Living Areas)Living rooms, kitchens, halls and other non-sleeping floor areas.30 psf · L/360
Floor Joists - 30 psf Live Load (Sleeping Areas)Bedrooms and attic floors (sleeping areas).30 psf · L/180
Rafters - 30 psf Ground Snow LoadSloped roof rafters where the ceiling is not attached to the rafters (30 psf ground snow load).20 psf · L/240
Ceiling Joists - 20 psf Live Load (Limited Attic Storage)Ceiling joists for attics with limited storage. Covers Douglas Fir-Larch and Hem-Fir per the published source table.Decks · DCA6
Deck Joists - DCA6Deck joist spans and allowable overhangs, No. 2 grade, 40 psf live load.Decks · DCA6
Deck Beams - DCA6Built-up and solid deck beam spans by the joist span they carry, No. 2 grade.