Parallel Chord Roof Truss Span Chart

Spans shown are in feet 4.

Parallel chord roof truss span chart.

Total load psf duration factor live load psf roof type 55 1 15 40 snow shingle 55 1 15 30 snow tile 47 30 snow 40 20 snow 1 25 20. Floor truss span tables alpine engineered products 17 these allowable spans are based on nds 91. Tcdl 10 psf and bcdl 5 psf 3. Tcll top chord floor live load 2.

72 5 0 mi ni m u m girder floor truss floor truss jacks a a bearing wall girder floor truss floor truss jacks bearing wall cantilevered floor truss two 2x rim joists 24 max. Roof floor truss manual 7 31 08 10 43 am page 12. You can use sbca s span charts to roughly determine truss sizes available. Spacing of trusses are center to center in inches.

Maximum deflection is limited by l 360 or l 480 under live load. And parallel to floor truss span strongback lateral supports 24 max. Jbs 11 17 truss types. Openings are to be located in the center of the span max opening width is 24 inches 7.

The offset scissor truss has a bottom chord that is flat for a distance and then is vaulted up and back down. Alpine truss designs are engineered to meet specific span configuration and load conditions. Keep in mind that these tables are for estimations only. Live load l 480 total load l 360 5.

The shapes and spans shown here represent only a fraction of the millions of designs produced by alpine engineers. Typical flat parallel chord trusses stepdown hip h ip g rde california hip. The bottom chord of the cap truss is typically moved up 1 1 2 for 2x4 continuous lateral restraints over the flat top chord of the base truss or the thickness of whatever material may be used 3 4 for plywood osb etc. The partial scissor truss is similar except that the bottom chord slopes up in one direction and then straight down while the remaining portion is flat.

Basic lumber design values are f 2000 psi f 1100 psi f 2000 psi e 1 800 000 psi duration of load 1 00. The cap truss is very similar to a gable truss with webs transferring loads vertically into the base truss below it. The important point to keep in mind when you use your truss calculator is that every truss calculation is completely unique and is based on the size of your roof and its specific dimensions. The truss is a framework consisting of rafters posts and struts which supports your roof.

Included are a series of representative roof truss span tables that will give you an idea of the truss spans available for a particular load condition load duration lumber type and truss configuration.