Category | Price | Seller | Device |
---|---|---|---|
Utilities | Free | American Wood Council | iPhone, iPad, iPod |
Maximum horizontal spans for joists and rafters are calculated based on the following assumptions and conditions:
· Joists and rafters are oriented to support vertical loads applied to the narrow (1.5 in. thick) face of the member, resulting in strong-axis bending.
· At least three joists or rafters are installed parallel to one another and spaced not more than 24 inches on-center, with properly designed sheathing attached on the top (compression) edge of each joist or rafter.
· Joists and rafters are single-span with adequate structural support at each end. The Span Calculator does not address cantilevered joists and rafters, multiple-span joists and rafters, or spliced joists and rafters.
· For joists and rafters, most building codes specify a minimum bearing length of 1.5 inches on wood or metal and not less than 3 inches on masonry or concrete. These minimum bearing lengths are to be used in the absence of calculated bearing lengths. Consult the local building code for specific requirements.
· Joists and rafters carry only combinations of dead load plus live load (D + L), dead load plus snow load (D + S), or dead load plus roof live load (D + Lr). The Span Calculator does not address wind load or seismic load.
· Buildings in regions with ground snow loads greater than 70 psf should not use the prescriptive provisions of the governing building code without approval of the authority having jurisdiction. Buildings in these high snow zones should be designed in accordance with accepted engineering practice.
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 American Wood Council nor its members assume any responsibility for any particular design prepared from this Span Calculator application. Those using this Span Calculator assume all liability from its use.
It has become a great tool for quick and accurate adjustments in design!
The update I received fixed the crash problem and it works well. Agree with the first reviewer on improvement suggestions. Just designed my friend's carport rafters with a 50 pcf snow load and cross checked. Works fine. Thank you!
Not as useful as I had hoped. I was expecting to be able to find span lengths for custom beam sizes. Guess I just wasted $20. If this is possible I apologize, please let me know.
I appreciate the idea. However, it doesn't lend itself to anything but "2x" construction and even then there is no option to sister members together. I would like to enter custom beam sizes and be able to sister commercial lumber.
Very simple to use and versatile. I do a lot of design build work and this program works wonderfully. 2x framing lumber specification for joist and rafter usage. Quicker than looking up span tables.
Calculates joists but not beams. Crashes when selecting wet service conditions from span options tab. Add larger woods and/or multiple smaller woods to make up beams.