Truss 101

Things to Specify

  • SPAN – the length of the bottom chord.
  • OVERHANG LENGTH – the horizontal distance from the end of the bottom chord to the bottom edge of the top chord. HOW MANY trusses you need can be easily determined as they are usually spaced 24 inches on center (O.C.).
  • DESIGN LOAD – the sum of the live and dead loads for top and bottom chords, plus the allowable stress increase.
  • The END CUT OF TRUSS, specify plumb cut, square cut or wild (not cut). See drawings above for reference.
  • For GABLE ENDS specify the type of gable end required: standard gable, dropped top chord, louvre size.
  • ROOF SLOPE – the vertical rise in inches per 12 inch horizontal run.
  • For SOFFIT RETURNS specify return information for soffit framing.
  • Specify TYPE OF TRUSS by indicating the truss configuration desired, such as kingpost, howe, scissor, etc.
  • For SPECIAL TRUSS TYPES specify all dimensions, cantilevers, etc.