Roof Trusses Weight Load

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.

Roof trusses weight load. This translates into a uniform load of 640 plf across 2 5 ft of the span. The load carrying capacity is handled by larger or higher graded material being used for the truss top and bottom chords as well as the webs. Bcll 0 psf no storage available in floor trusses. If you have another floor above your garage the ceiling floor structure can usually support up to 40 lbs sqft including the weight of the floor above it.

In engineering calculations the span of a beam a truss is a beam is squared. That means you could lay a 2 x 4 ft. The horizontal bottom chords of most garage trusses are designed to carry the weight of drywall and insulation. So if your ceiling is unfinished you have some excess carrying capacity up there.

Safe load per table 4 1 specifies a 2000 lb over a 2 5ft x 2 5ft area. The truss is analyzed for each possible location of the 640 plf load along the span. This means a 30 foot span is 50 wider than a 20 foot span but must have 225 of the load carrying capacity. For trusses at 2 ft o c.

If you do not have another floor above the ceiling trusses may only be able to hang a maximum of 10 lbs sqft. If the number of members is labeled m and the number of nodes is labeled n this can be written as m 3 2 n. The live loads a truss is required to bear are determined by local building codes. Of stuff on it.

Scrap of plywood over the chords and set about 40 lbs. Don t forget to add all roof assembly materials when calculating total roof weight. The formula for truss loads states that the number of truss members plus three must equal the twice the number of nodes. When it comes to estimating the weight of an existing roof field verification of the in place construction is necessary.