Attic Joist Span

Span exceeds 26 feet in length.

Attic joist span.

Ceiling joist span tables. This sample table gives minimum floor joist sizes for joists spaced at 16 inches and 24 inches on center o c for 2 grade lumber with 10 pounds per square foot of dead load and 40 pounds of live load which is typical of normal residential construction. For example the highlighted cell below shows that a 2 x 6 southern yellow pine joist with a grade of 2 and spaced 24 apart can have a maximum span of 10 feet 0 inches 10 0 if you are designing your structure to support a plaster ceiling. Span length is different for every room.

Also available for the android os. 1 inch 25 4 mm 1 foot 304 8 mm 1 pound per square foot 0 0479kpa. For uninhabitable attics without storage we will use table r802 4 1 and for uninhabitable attic with limited storage we will use table r802 4 2. Now lets take a look at those tables.

It is safe to say though that 2x6 ceiling joists spaced every 24 inches on center a typical arrangement found in attics will not support live loads for a bedroom office or bathroom. As mentioned above the span tables within the code list the allowable ceiling joist spans for common lumber sizes based on what design load scenario is applied. Ceiling joist spans for common lumber species uninhabitable attics with limited storage live load 20 psf l δ 240 check sources for availability of lumber in lengths greater than 20 feet.