Minimum Weight Design Of Long Span Roof Truss

Depending on your roof slope add 4 to 5 inches for heel height.

Minimum weight design of long span roof truss. The more complex the truss framework is the greater quantity of these joints will be required. The same thing is true for the bridge of the truss. Roofing paper inch plywood decking under tile roofing. A series of 30 ft 2 by 4 fink roof trusses spaced at 2 ft on center with 6 12 pitch are to be designed for use in a residence.

The span of the trusses their installed height above grade and or the acces sibility or availability of mechanical installation equipment such as a crane or forklift. Member of a truss. 30 psf design roof snow load heavy clay tile roofing no mortar 30 lb. The construction documents also provide the following information.

The load span tables shown below demonstrate only a tiny subset of the possible combinations available with trussteel cfs roof trusses. Roof truss span tables alpine engineered products 15 top chord 2x4 2x6 2x6 2x4 2x6 2x6 2x4 2x6 2x6 2x4 2x6 2x6 bottom chord 2x4 2x4 2x6 2x4 2x4 2x6 2x4 2x4 2x6 2x4 2x4 2x6 2 12 24 24 33 27 27 37 31 31 43 33 33 46 2 5 12 29 29 39 33 33 45 37 38 52 39 40 55 3 12 34 34 46 37 39 53 40 44 60 43 46 64 3 5 12 39 39 53 41 44 61 44 50 65 47 52 70. Compromised trusses can lead to severe structural problems such as bowing exterior walls sagging ridge lines and roof collapse. If dead loads must be hung from trusses then extra support can be provided by installing support beams perpendicular to the trusses reducing the span of the bottom chords and increasing their ability to carry the weight load.

Level returna lumber filler placed horizontally from the end of an overhang to the outside wall to form a soffit. If you can t get the heel height most residential trusses will have a 3 top cord. Trusses can be constructed with smaller sized lumber than rafters and often their cost is not significantly higher than normal rafters. Use of manufactured roof trusses can dramatically cut labor costs when framing a gable roof compared to building rafters.

L d ratiothe ratio of the truss span l to its depth d both dimensions in inches. Calculate the height of a common truss using the building width and the slope of the roof. Live loadany temporary applied load to a floor truss chord. Finally the truss calculator will compute the best dimensional method to connect the pieces of the truss with steel joints and a bridge.

Total designed load 25 pound per square foot 6 29 pound per square foot 2 35 pound per square foot 18. Typically roof live load is snow while floor live loads are furniture.