Roof Truss Step Bottom Chord

One truss cut only at the third point.

Roof truss step bottom chord.

The span in short is the length of the bottom of the truss. This is where you will make a bottom chord. It has been cut adjacent to a node point. The bottom chord establishes the lower edge of a truss.

To reinforce the ends of the trusses 3 4 inch plywood gussets were to be attached to both sides of each truss with 10d nails 3 inches on center on all chords. The node gang nail at the cut point looks in distress and has partially pulled out. 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. Create a bottom chord while you have established the angle of the trusses with your rafter pieces and cut them in the necessary lengths they still need more support to finish the structure.

Some spans have a lower rate per foot than others. The bottom chord therefore carries combined stress of both tension and bending of the truss. For example if a truss has a span of 26 then the bottom chord can be built with two boards 16 and 10 which allows for no scrap and waste and is the most efficient for price savings. A domestic roof engineered truss has had the bottom cord cut to install an attic access hatch door.

The adjoining trusses appear slightly out of plain. Most economical when the difference in slope between the top and bottom chords is at least 3 12 or the bottom chord pitch is no more than half the top chord pitch. The bottom chord is the bottom horizontal or inclined member of a truss.