Minimum Weight Design Of Long Span Roof Truss

The same thing is true for the bridge of the truss.

Minimum weight design of long span roof truss.

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. If you can t get the heel height most residential trusses will have a 3 top cord. Typically roof live load is snow while floor live loads are furniture.

Total designed load 25 pound per square foot 6 29 pound per square foot 2 35 pound per square foot 18. Roofing paper inch plywood decking under tile roofing. The more complex the truss framework is the greater quantity of these joints will be required. 05425 cold formed steel trusses roof truss spans every trussteel roof truss is a custom design based upon the unique load span bearing use and code criteria of a particular project.

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. Use of manufactured roof trusses can dramatically cut labor costs when framing a gable roof compared to building rafters. The load span tables shown below demonstrate only a tiny subset of the possible combinations available with trussteel cfs roof trusses. Live loadany temporary applied load to a floor truss chord.

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. The construction documents also provide the following information. 30 psf design roof snow load heavy clay tile roofing no mortar 30 lb.

The installer should be knowledgeable about the truss design drawings truss placement plans and all notes and cautions thereon. Member of a truss. Trusses can be constructed with smaller sized lumber than rafters and often their cost is not significantly higher than normal rafters. Level returna lumber filler placed horizontally from the end of an overhang to the outside wall to form a soffit.

These steel joints are needed to support the overall truss. 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.