Ceiling Joist Roof Span Calculator

Use the span tables below to determine allowable lengths of joists and rafters based on size and standard design loads.

Ceiling joist roof span calculator. Ceiling joists of the first floor of a two story structure often serve as floor joists for the second floor. If a room is 10 inside to inside and the joists are cut 10 7 so they will bear fully on both walls then the span will be 10. For example if building is 24 x 24 and has trusses and the load on the roof will be for 30 lb snow load and a ceiling with no storage will total out like this. You can also use the wood beam calculator from the american wood council website to determine maximum rafter and joist lengths.

Also available for the android os. This will be slightly less than the length of the board. Span calculator for wood joists and rafters also available for the android os. Flat roof joists.

Flat roof joist calculator. The load on an outside wall with clear span trusses is exactly half the load on each wall. The full version allows any size. Span calculator for wood joists and rafters also available for the android os.

Also available for the android os. This demo version is fixed at 1m clear span. If this is the case with your structure use the floor joist table to determine maximum joist length load. 1 enter joist details 1 1 span and joist spacing.

In other words it is either going to be on an outside wall or somewhere on the inside. This is the distance between joist centres. While every effort has been made to insure the accuracy of the information presented and special effort has been made to assure that the information reflects the state of the art neither the west coast lumber inspection bureau the american wood council nor its members assume any responsibility for any particular design prepared from this online span calculator. While every effort has been made to insure the accuracy of the information presented and special effort has been made to assure that the information reflects the state of the art neither the west coast lumber inspection bureau the american wood council nor its members assume any responsibility for any particular design prepared from this online span calculator.

Enter a span for the joist.