Framing A Truss

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Framing A Truss

• Luke Rhine
• Reservoir High School

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Types of Trusses
Medium Spans MOST COMMONLY USED
Small Spans
Large Spans
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Types of Trusses

• Various need truss types

Commonly used for barns / sheds / garages.
Commonly used when a room is placed in the attic
or when a crawl space is required in the attic
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Types of Trusses

• Various need truss types

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Terminology
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Terminology

• Peak - Point on the truss where the sloped chords
  meet.
• Slope / Pitch - The incline angle of the roof.
  Described as the ratio of total rise over the
  total width or run. An interior diagonal member
  of the truss structure.
• Web - An interior diagonal member of the truss
  structure.
• Heel - Point on a truss at which the top and
  bottom chords intersect.

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Terminology

• Cantilever - The part of a truss that extends
  beyond its support, exclusive of its overhang.
  Note the overall span of the truss is to include
  length of cantilever. Ex 28' truss with 2'
  cantilever equals a truss with a 2' cantilever
  and the distance between two outside bearings
  equals 26'.
• Bottom Chord - A horizontal or inclined member
  that establishes the bottom member of a truss.

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Terminology

• Top Chord - An inclined or horizontal member that
  establishes the top member of a truss.
• Bearing Point - A structural support, usually a
  beam or a wall that is designed by the building
  designer to carry the truss reaction loads to the
  foundation.
• Overhang - The extension of the top chord of a
  truss beyond the outside of the bearing support
  or the bottom chord.

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Rules When Framing

• Ordering Trusses
• Roof trusses are generally made to order for a
  given construction or remodeling job, and they
  usually require about 2 to 3 weeks of lead time.
• On most projects, your lumberyard or home center
  can place the order for you, but you must supply
  the dimensions, pitches and styles (gable, hip,
  flat). Those are usually available on the plan
  (which you need to get your permits anyway).

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Rules when Framing

• Positioning and Bracing Trusses
• After the trusses are all stacked up on the wall
  plates, you then walk them back into position one
  at a time starting with the second gable end
  truss (which goes on the far end from where the
  trusses are stacked) working your way back to the
  first gable end.
• Mark those off with the same 24" on center
  sequence that you marked on the wall plates.

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Rules when Framing

• Positioning and Bracing Trusses
• Then once you have a few of the trusses in place,
  nail the end of the brace over the second gable
  end truss up along the peak and then nail it to
  the other trusses, lining each one up with the
  marks you made. That'll not only set the proper
  spacing but it will also plumb up the other
  trusses (assuming the gable end truss is still
  plumb).

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Examples
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Examples
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Examples