Rafter: A sloping roof framing member.
Rake: Edge of a roof with the intersection of the gable.
Reaction: Forces acting on a truss, through its support, that are equal but opposite to the sum of the dead and live loads.
Ridge: The horizontal line made by the top surfaces of the two sloping roof surfaces.
Rise: Vertical distance from the bottom of the top chord at the butt cut to the bottom (inside) of the top chord or from the top of the top chord at the heel to the top of the top chord at the peak.
Scab: Additional timber connected to a truss to effect a splice, extension or general reinforcement.
Scupper: Roof drain.
Seat Cut: Horizontal cut made on the bottom of a sloping bottom chord to provide a level bearing surface.
Set Back: The distance from the outside edge of the wall exclusive of veneer, to the face of a hip master (girder) truss.
Slider: Two inch dimension lumber inserted between the top and bottom chords at the heel joint in the plane of the truss to reinforce the top or bottom chord.
Slope: Same as Pitch.
Sloped Soffit: Sloped overhang with no level return.
Snow Load: Same as GSL Ground Snow Load.
Soffit: The under side of a roof overhang or truss cantilever end.
Span: Term generally used to communicate out-to-out span, or overall span of a truss design. Sometimes also indicates centerline to centerline of bearing.
Splice Point: The point at which two chord members are joined together to form a single member. It may occur at a panel point or between panel points.
Square Cut: End of top chord perpendicular to the slope of the member. Cut made at 90 degrees to the length of the member.
Strongback: Two inch dimensional framing member attached perpendicular to floor trusses – often through the chase opening – and placed vertically against the vertical web.
Stub Truss: A term used to describe a truss that is clipped at one end.
T-Brace: A brace consisting of two-inch dimension lumber nailed directly to the member requiring a brace, and with the width of the member perpendicular to the width of the brace.
Toenail: A nail driven at an angle to the member.
Top Chord: An inclined or horizontal member that establishes the top member of a truss.
Top Chord Bearing: The bearing condition of a parallel chord truss that bears on its top chord extension. Can also apply to a sloping chord truss bearing on a top chord extension.
Top Plate: Framing consisting of two members On The Flat that forms the top of exterior stud bearing walls of platform frame construction.
Truss: An engineered structural component, assembled from wood members, metal connector plates and other mechanical fasteners, designed to carry its own weight and superimposed design loads. The truss members form a semi-rigid structural framework and are assembled such that the members form triangles.
Truss Clip: Metal component designed to provide structural connection of trusses to wall plates to resist wind uplift forces.
Truss Engineering Drawing: Drawing prepared by a Professional Engineer which prescribes truss geometry (span, slope, panel point locations, lumber, plate type, size and location, design loads, spacing, forces, etc.) usually required for manufacturing and building inspection.
Truss Layout: Plan view of entire project created by the truss manufacture to indicate proper truss placement and location.
Truss Spacing: The on center distance between trusses.
Valley: The angle formed by two sloping sides of the roof.
Web Member: Internal members that join the top and bottom chord, to form the triangular patterns typical of trusses. These members typically carry axial forces.
Wedge: A triangular piece of lumber that has one side equal to the standard two-inch dimension lumber widths, and is inserted between the top and bottom chords, usually to allow the truss to cantilever. Its used is determined through engineering analysis.
Wind Load: Load applied to the roof by wind.