Roof Truss Self Weight

The live loads a truss is required to bear are determined by local building codes.

Roof truss self weight.

Total floor area less than 200m2 and where roof shape calculations have not been made the. You need not to use formulato calculate the self weight. When it comes to estimating the weight of an existing roof field verification of the in place construction is necessary. The soffit weight approx.

Medium term loads for small buildings ie. However i am wondering if the drawings indicate the truss is to be designed for 20 psf ll and 10 psf dl does the truss manufacturer include the self weight of the truss in that 10 psf or is the 10 psf considered a superimposed dead load and they add in the self weight of the truss separately. If you know the mass per unit length you can calculate the self weight by. Pitch slope the pitch or slope is the incline of the roof expressed as a fraction describing the rise over the run.

The rise will be the elevation change over the 12 inches. It is very easy to calculate the self weight of the truss. The truss are 36 in height. Tile weight 575 n m 2 truss self weight 75 n m 2 battens felt 35 n m 2 685 n m2 where a rafter bay forms part of the room in raised tie and attic trusses an additional load of 250 n m2 is added for the ceiling finishes.

Asphalt shingle or asphalt fiberglass composite shingle 2 7 lbm ft2 13 2 kg m2 metal roofing aluminum or steel panel sheet or shingle 1 2 lbm ft2 5 9 kg m2 terne plate copper bearing steel sheet 0 7 lbm ft2 3 4 kg m2 wood shingle or shake 2 4 lbm ft2 11 7 kg m2 zinc roofing 1 6 lbm ft2 7 8 kg m2. Dead load weight of roof trusses top chord bottom chord webs weight per lineal foot plf 2x4 2x4 2x4 4 3 2x4 2x8 2x4 5 6 2x6 2x4 2x4 4 8 2x6 2x6 2x4 5 5 2x6 2x6 2x6 6 2 2x6 2x8 2x4 5 9 2x6 2x10 2x4 6 6 2x6 2x10 2x6 7 2 2x8 2x8 2x4 6 6 2x8 2x8 2x6 7 2 2x8 2x10 2x8 8 4 dead load weight of floor trusses depth in inches top chord bottom chord. Pre manufactured stock trusses are constructed with spruce pine fir spf or southern yellow pine syp lumber. For example a slope of 6 12 means for every 12 inches of horizontal distance the slope of the roof will rise 6 inches vertically.

The run or the base number is 12 inches. 4000 00 pounds with 1 4 drywall. 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. The studs are metal.

These trusses the meet building code criteria as specified by structural building components of america sbca and the truss plate institute tpi. Don t forget to add all roof assembly materials when calculating total roof weight.