Roof Truss Chord

Closed open distinction is used in two ways to describe truss roofs.

Roof truss chord.

For example table 3 5 1 allows identical trusses to vary in span by as much as 1 2 in. These trusses are positioned on the top plate of the endwall so the entire bottom chord is supported by the wall. And in height by as much as 1 4 in. The same thing is true for the bridge of the truss.

End trusses close in the end of a building and provide a nailing surface for the upper end wall or rigid sheathing. Truss that creates roof planes and does not support other trusses truss that creates hip plane by truncating and allowing hip jacks truss top chords to fly over. There are three parts to the roof truss that you have to know. These steel joints are needed to support the overall truss.

The bottom chord which is the bottom of the framed truss. Then there is the top chord or rafters that are angled to make the roof pitch. 500 sycamore street p o. Dropped chord roof truss.

Hip end trusses that are supported by. In span and 1 2 in. Closed in which the bottom chord is horizontal and at the foot of the truss and open in which the bottom chords are raised to provide more open space also known as raised bottom chord trusses. See gusset construction below.

Bottom chords is at least 3 12 or the bottom chord pitch is no more than half the top chord pitch. The chord size and web configuration are determined by span load and spacing. Finally there are the gussets that hold the framed truss together. Complying with the erection tolerances specified in sbca s bcsi b1 summary sheet is critical to achieving an acceptable roof line.

There are two main types of timber roof trusses. Hip end trusses that are supported by hip truss and creates hip plane. Variance from the design dimensions is also allowed. It is most often used for roof construction.

All truss designs are optimized to provide the most economical configuration for the specific application. Finally the truss calculator will compute the best dimensional method to connect the pieces of the truss with steel joints and a bridge. The parallel chord or flat truss gets its name from having parallel top and bottom chords. Box 177 la crescent mn 55947 507 895 8400.

Any weight imposed on the end truss is directly transferred to the endwall which transfers the weight to the foundation. Some common trusses are named according to their web configuration such as the king post fan fink or howe truss. Truss that supports creeper trusses and creates hip roof plane. Flat the most economical flat truss for a roof is provided when the depth of the truss in inches is approximately equal to 7 of the span in inches.