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.

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.