Attic Truss Load Rating

This translates into a uniform load of 640 plf across 2 5 ft of the span.

Attic truss load rating.

Safe load per table 4 1 specifies a 2000 lb over a 2 5ft x 2 5ft area. Total load psf duration factor. So if your ceiling is unfinished you have some excess carrying capacity up there. The truss is analyzed for each possible location of the 640 plf load along the span.

Or the 25 psf snow load could be entered as a roof snow load with the unbalanced snow loading option turned off. The live loads a truss is required to bear are determined by local building codes. If unbalanced snow loading isn t required or specified the truss designer may enter the 25 psf snow load as a top chord live load tcll set the load duration factor to 1 15 for snow and turn snow loading off completely. Of stuff on it.

For trusses at 2 ft o c. The horizontal bottom chords of most garage trusses are designed to carry the weight of drywall and insulation. If the bottom chord of a roof truss functions as a floor joist such as in an attic room it carries a live load that also varies by use but a typical live floor load for a residential space is about 40 pounds per square foot. That means you could lay a 2 x 4 ft.

Both sides of the equation should be equal in order to end up with a stable and secure roof structure. They have not been updated for the change in lumber values within the last decade. Live load psf roof type. Bcll 0 psf.

Keep in mind that these tables are for estimations only. Is a safe estimate. This truss load table guide illustrates how to read allowable load ratings for aluminum and steel truss. The explanations below will help you determine the appropriate truss to use for your application or conditions based on allowable load ratings.

The box truss is 290mm x 290mm 11 42 x 11 42 square. Bcll 0 psf no storage available in floor trusses. Alpine truss designs are engineered to meet specific span configuration and load conditions. The shapes and spans shown here represent only a fraction of the millions of designs produced by alpine engineers.

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. Scrap of plywood over the chords and set about 40 lbs.