The terms in the above
image are typically used to describe the various parts of a metal plate
connected wood truss. The truss profile, span, heel height, overall height,
overhang and web configuration depend on specific design conditions and
will vary by application.
We will design to
suit your needs!
Here are some definitions
of common roof truss terms:
- Bottom Cord -
The main member of a truss running along its lower side between supports
and usually carrying combined tension and bending.
- Cantilever - The
condition where top and bottom chords extend beyond a support with no
bearing at the extended portion.
- Clear Span - Horizontal
measurement between the inside faces of the bearing supports.
- Heel - The point
on a truss at which the top and bottom chords intersect, usually occurring
- Level Return -
A horizontal member of the truss running from the end of the overhang
back to the outside of the wall to form a soffit.
- Nominal Span -
Horizontal distance between outside edges of supports.
- Overall Truss
Length - The horizontal length of truss including the cantilever, but
not the overhang.
- Overhang - The
extension of a top or bottom chord of a truss beyond a support.
- Panel Point -
A point at which one or more web members intersect the top or bottom
- Panel Length -
The centerline distance measured horizontally between two panel points.
- Peak - The point
on a truss where the sloping top chords meet.
- Pitch - The inches,
or fraction thereof, of vertical rise in 12 inches of horizontal run
for inclined members. Usually expressed as 4/12, 8/12, etc.
- Purlin - Horizontal
member placed between two main load carrying structural members. They
can be used as spacers carrying decking or roofing materials and providing
some lateral support for the main members.
- Slope - See Pitch.
- Top Chord - Main
member of a truss running along its upperside supporting the decking
and usually carrying combined compression and bending.
- Webs - Members
that connect top and bottom chords together forming triangular openings
to give truss action and usually carrying compression or tension forces.